Association between salivary /microbiological parameters, oral health and eating habits in young athletes

BACKGROUND

Athletes' oral health can impact overall well-being and sports performance. This study aimed to evaluate the interactions between eating habits and oral health of 120 young athletes as compared to 30 age-matched individuals not practicing sports based on a questionnaire and the analysis of saliva.

METHODS

One hundred twenty subjects practicing various sports activities (test group) and 30 subjects not practicing sports (control group) were selected. A self-administered questionnaire was used to obtain personal data, hours and frequency of weekly training, complete pathological history, history of hard and soft tissues of the oral cavity, family history, and oral hygiene practices. The eating habits of the young participants were analyzed by investigating the number of daily meals; use and frequency in sports practice of supplements/energy drinks, fruit/juices, snacks, chocolate; daily diet; and differences between usual diet and pre-competition diet. At baseline (T0), each participant was clinically assessed for the determination of the number of decayed, missing, and filled teeth (DMFT), Silness & Löe Plaque Index (PI), and the Löe & Silness Gingival Index (GI) and qualitative analysis for the presence/absence of stains and dental erosions. At T0, before (T1) and after training sessions (T2), saliva was collected to determine resting pH, Streptococcus mutans, and Lactobacillus spp counts.

RESULTS

Test groups were trained more than 2 h, 5 times a week. Soccer players and skiers had a high percentage of caries; water polo players demonstrated the highest percentage of erosions and dental stains. Salivary resting pH showed statistically different values in three different observations between the groups. S. mutans was harbored by 60% of soccer and 70% of water polo players, while Lactobacillus spp in 43.33% of the swimmers and soccer players. Combining all the 56 variables including the clinical examination, self-reported parameters, and salivary analysis, we have identified water polo players as a distinct at-risk group for developing dental defects, expressed as an aggregate disease score. In particular, we have found that energy snacks/chocolate intake is strongly associated with ratio of S. mutans/Lactobacillus spp and that S. mutans is linked to dental defects (R = 0.88). Linear regression analysis indicates that energy snacks/chocolate intake in the study population represents a strong driver for oral dysbiosis and dental disease.

CONCLUSIONS

Our study clearly shows that athletes should follow a balanced diet that not only satisfies their nutritional needs but also avoids oral dysbiosis and subsequent dental damage.

Porphyromonas gulae and canine periodontal disease: Current understanding and future directions

Porphyromonas gulae has emerged as a notable pathogen in canine periodontal disease, akin to Porphyromonas gingivalis in human periodontitis. This review examines the initial isolation, phylogenetic analysis, habitat, host range, relationships with host health status and age, and key pathogenic determinants, including fimbriae, proteases, citrullinating enzyme, and lipopolysaccharide. Control strategies discussed include polyphosphate to disrupt haeme/iron utilization, clindamycin with interferon alpha to reduce bacterial load and enhance the immune response, and a protease inhibitor. Further research is needed to understand strain-level diversity of virulence factors and interactions between P. gulae and other oral bacteria, particularly Fusobacterium nucleatum, a common pathogen in both dogs and humans. The potential for interspecies transmission between dogs and humans warrants further research into these interactions. Extensive in vivo studies across various breeds are crucial to validate the effectiveness of proposed treatment strategies. This review emphasizes P. gulae's role in periodontal health and disease, setting the stage for future research and improved management of canine periodontal disease.

Antimicrobial hybrid coatings: A review on applications of nano ZnO based materials for biomedical applications

The extreme survivability of infectious microorganisms on various surfaces prompts for the risk of disease transmissions, posing a perilous concern for global health. Thus, the treatment of these pathogenic microorganisms using the nanomaterials functionalized with antimicrobial coatings reaps relevant scope in the ongoing trend of research. Driven by their admirable biocompatibility, cost-effectiveness, and minimal toxicity, ZnO nanoparticles (ZnO-NPs) based antimicrobial hybrid coatings have emerged as a robust material to prevent the growth of infectious microorganisms on various surfaces, which in turn boosted their applications in the area of biomedical sciences. In this context, the current review focuses on the synthesis of ZnO-NPs based hybrid coatings using different polymers and inorganic materials for effective utilization in biomedical domains including dentistry, orthopedics, implantable medical devices and wound healing. The synergistic effect of ZnO-NPs hybrids with remarkable antibacterial, antifungal and antiviral property has been discussed. Finally, we highlight the future potential of ZnO-NPs based antimicrobial hybrid coatings for potential clinical translation.

Magnification: The game changer in dentistry

During dental examinations and treatments, many dentists are using magnification to improve their vision. The dental operating microscope serves as the most effective tool for this purpose, enhancing the quality, longevity, and outcome of clinical work. This review will explore the latest research and data on the importance of magnification devices in dentistry, including diagnostic methods, treatment options and ergonomics in specialities such as restorative dentistry, endodontics, pedodontics, periodontics, and prosthodontics. This review aims to provide insights into the optimal magnification for different clinical situations, the specific benefits of dental operating microscopes for each dental branch, and their limitations.

Biaxial flexural strength and surface characterization of multilayer zirconium dioxide after polishing, glazing and clinical adjustments

PURPOSE

To evaluate how laboratory polishing and glazing and clinical adjustments, i.e., by grinding and polishing affect the biaxial flexural strength and surface characterization of multilayer zirconia.

METHODS

Specimens of KATANA™ Zirconia YML, containing Enamel-Body 1 or Body 2-3 layers, and UTML were divided into 18 groups (n = 11) according to material/layer and finish treatment: laboratory polishing, glazing, or both, or followed by clinical adjustments. The surface roughness, surface structure and elemental composition were evaluated. Thermocyclic-mechanical cyclic loading and biaxial flexural strength test were performed. Three- and two-way ANOVA were used (α = 0.05).

RESULTS

The yttrium amount decreased in the order UTML, YML Enamel-Body 1, and YML Body 2-3. Body 2-3 showed higher flexural strength than Enamel-Body 1 and UTML, in that order. Flexural strength after clinical adjustments was higher in Body 2-3 but lower in Enamel-Body 1 and UTML. Finish treatments had indistinguishable impact on Enamel-Body 1. Body 2-3 had higher strength after polishing, polishing and glazing, and glazing, in that order. UTML displayed the highest strength after polishing and glazing or glazing. The surface roughness was lowest after polishing regardless of material/layer.

CONCLUSIONS

Laboratory treatments and clinical adjustments of multilayer zirconia affect the flexural strength and surface roughness differently depending on the zirconia type. Composition-gradient zirconia should be polished, and shade-gradient zirconia (≥ 5 mol% yttria) should be polished and glazed. Clinical adjustments of zirconia with higher yttria content are detrimental for the flexural strength and should be performed with caution.

Advanced biomaterials for targeting mature biofilms in periodontitis therapy

Periodontitis is a chronic inflammatory disease primarily caused by bacteria, leading to inflamed and bleeding gums, periodontal pocket formation, and bone loss. Affecting 70%-90% of adults over 65, periodontitis is a leading cause of tooth loss and significantly impacts quality of life. Standard treatments, including subgingival scraping and antibiotics, have limitations, and antibiotic resistance among periodontal pathogens is an increasing concern. Biofilms are barriers to drugs and immune responses, contributing to bacterial resistance and reducing antibiotic effectiveness. Due to their adjustable physicochemical properties, bioactive materials potentially eliminate bacterial biofilms, presenting a promising alternative for periodontitis therapy. In this review, the recent innovations in biomaterials for removing mature biofilms in periodontitis are examined, and their broader potential is discussed. Additionally, the compositions of bacterial biofilms, formation pathways, and intrinsic drug resistance mechanisms are discussed. Finally, the strategies for optimizing subgingival biofilm removal in periodontitis are highlighted, such as targeting biofilms-embedded bacteria, disrupting the extracellular polymeric substances, and utilizing combined approaches. A comprehensive understanding of the properties of biomaterials guides the rational design of highly targeted and effective therapies for periodontitis.

Magnesium-substituted zinc-calcium hydroxyfluorapatite bioceramics for bone tissue engineering

Hydroxyfluorapatite (HFAp) materials possess a structural and compositional similarity to bone tissue and dentin. These bioceramics facilitate various physiological functions, including ion exchange within surface layers. Additionally, magnesium (Mg) serves as a primary substitute for calcium in the biological apatite found in the calcified tissues of mammals, while zinc (Zn) contributes to overall bone quality and exhibits antibacterial properties. Although multiple studies have examined the individual substitution of ions within the hydroxyapatite (HAp) structure, no research to date has investigated the simultaneous substitution of zinc, fluoride, and varying amounts of magnesium in calcium HAp. This study explores the incorporation of magnesium into the structure of zinc-calcium hydroxylfluorapatite. A series of ion-substituted apatites, represented as Ca9.9-xZn0.1Mgx (PO4)6(OH)F with 0 ≤ x ≤ 1, were synthesized. Characterization of the produced samples confirmed that they were monophase apatite, crystallizing in the hexagonal P63/m space group, with only a slight impact on crystallinity due to magnesium doping. Pressure-less sintering of the samples demonstrated that maximum densification, approximately 94%, was achieved at 1200 °C with a sintering dwell of 1 h for the sample with x = 0.1. Furthermore, the Young's and Vickers hardness of this sample reached peak values of 105 and 5.02 GPa, respectively. When immersed in simulated body fluid, the formation of an amorphous CaP which can subsequently be crystallized into crystalline phase on the surface of dense specimens was observed, indicating the ability to bond with bone in a living organism and their potential use as substitutes for failed bone and dentin filling and coating.

Reduction of stress-shielding and fatigue-resistant dental implant design through topology optimization and TPMS lattices

To improve longevity and performance of dental implants by reducing stress-shielding, a modification of the internal structure of the implant can be a solution. In this paper the inner design of the implant is generated either using a topology optimization approach or an approach based on TPMS lattice structures. These approaches aim to maintain long-term stability and to reduce stress-shielding. For both approaches, the mechanostat model was applied to investigate the influence of the inner structure to the surrounding bone tissue and compare the standard uniform implant. For the investigation an ANSYS model was used with material parameters obtained from a mechanical test of additively manufactured Ti6Al4V. Compared to the uniform implant, the topology-optimized implant showed 20% less stress-shielding, and the implant with triply periodic minimal surface structures (TPMS) showed 15% less stress-shielding. Further, the long-term-stability was investigated by introducing a high-cycle fatigue material model. Despite a change in the internal structure and a 45% reduction in the mass of the topology-optimized implant, the cycle numbers specified in the DIN EN ISO 14801 standard were fulfilled.

Biomaterials and therapeutic strategies designed for tooth extraction socket healing

Tooth extraction is the most commonly performed oral surgical procedure, with a wide range of clinical indications. The oral cavity is a complex microenvironment, influenced by oral movements, salivary flow, and bacterial biofilms. These factors can contribute to delayed socket healing and the onset of post-extraction complications, which can burden patients' esthetic and functional rehabilitation. Achieving effective extraction socket healing requires a multidisciplinary approach. Recent advancements in materials science and bioengineering have paved the way for developing novel strategies. This review outlines the fundamental healing processes and cellular-molecular interactions involved in the healing of extraction sockets. It then delves into the current landscape of biomaterials for socket healing, highlighting emerging strategies and potential targets that could transform the treatment paradigm. Building upon this foundation, this review also presents future directions and identifies challenges associated with the clinical application of biomaterials for extraction socket healing.

Upregulation of RCN2 accelerates tumor progression and indicates poor prognosis in OSCC

OBJECTIVE

Oral squamous cell carcinoma (OSCC) is a prevalent cancer of the head and neck region. However, the potential role of RCN2 in OSCC is currently not well understood.

STUDY DESIGN

A series of molecular biology experiments were conducted to explore the mechanism by which RCN2 promotes OSCC growth through protein kinase A (PKA).

RESULTS

Our results revealed a significant increase in RCN2 levels in OSCC tissues. Moreover, OSCC patients with high RCN2 expression had a significantly worse prognosis than those with lower RCN2 expression. Interestingly, PKA activity was increased in RCN2-overexpressing YD-10B cells but reduced in RCN2-knockout Ca9-22 cells. These findings suggest that RCN2-mediated PKA activity is activated in OSCC cells. Moreover, the specific PKA inhibitor H89 significantly reduced the proliferation ability of RCN2-overexpressing Ca9-22 cells. Furthermore, we identified AKT/mTORC as a downstream pathway through which PKA promotes OSCC cell proliferation. The Tumor Immune Estimation Resource database revealed that the expression level of RCN2 was correlated with the infiltration levels of B cells, CD8+ T cells, CD4+ T cells, and neutrophils in the microenvironment of OSCC.

CONCLUSIONS

Our study revealed that RCN2 promotes tumor progression by activating PKA/AKT/mTORC signaling, which suggests that RCN2 may serve as a potential target for OSCC treatment.

The Effect of Angulation and Scan Body Position on Scans for Implant-Treated Edentulism: A Clinical Simulation Study

INTRODUCTION

The acquisition of digital impressions has become an integral part of clinical dentistry. The purpose of the present clinical simulation study was to evaluate the accuracy of digital impressions for maxillary full-arch implant-supported prostheses using two modern intraoral scanners with different acquisition technologies.

MATERIAL AND METHODS

Two models of edentulous maxilla, with six implants at positions #16,14,12,22,24,26 (FDI World Dental Federation System, ISO 3950) or #3,5,7,10,12,14 (Universal Numbering system) were digitally designed, and 3D-printed in resin material (Asiga DentaMODEL, Australia). In the first scenario, all implants were parallelized, while in the second, implants #12/#7 and #22/#10 had a 20° angulation buccally, while implants #16/#3 and #26/#14 20° angulation distally. The models were scanned with two different intraoral scanners, Trios3 (3Shape, Denmark) and CS3600 (Carestream Dental, USA). Linear (x, y, z axes-top point) and angular deviations (x, y, z axes-Δφ) were assessed. Statistical analysis was performed using Kolmogorov-Smirnov tests (significance at p < 0.05).

RESULTS

Implant angulation showed a significant impact on accuracy, while the two scanners showed statistically significant differences. CS3600 demonstrated superior trueness, while Trios3 superior precision in both clinical scenarios. In the first clinical scenario a predominant occurrence of angular deviations was observed, while in the second scenario both angular and linear deviations were recorded. Scan body position also influenced scanning outcomes, with the last scan body captured demonstrating higher deviations.

CONCLUSION

Both scanners provided acceptable accuracy in the acquisition of digital impressions. Implant angulation and scan body position significantly affected trueness and precision. Clinicians should carefully consider implant angulations in full-arch implant restorations, as well as the scanning protocol.

In situ remineralization of enamel caries lesions with a toothpaste supplemented with fluoride, amorphous calcium phosphate casein phosphopeptide and trimetaphosphate

OBJECTIVES

This in situ study aimed to evaluate the effect of a new toothpaste formulation containing fluoride (F), casein phosphopeptide amorphous calcium phosphate (CPP-ACP) and sodium trimetaphosphate (TMP) on the remineralization of initial caries lesions.

METHODS

This was a blind, crossover study, performed in 5 experimental phases with a duration of 3 days each. At first, the initial surface hardness (SH) and hardness after demineralization (SH1) were determined. Then, volunteers (n = 10) used palatal appliances containing 4 bovine enamel specimens with initial caries lesions. The treatment regimens were: 1) Placebo (No F-TMP-CPP-ACP), 2) 1100 ppm F (1100F), 3) 1100F+3 %TMP (1100F-TMP), 4) 1100F+10 %CPP-ACP (1100F-CPP-ACP) and 5) 1100F-CPP-ACP-TMP. After 3 days, the final surface hardness (post-remineralization) (SH2), percentage of surface hardness recovery (%SHR), integrated recovery of subsurface hardness (ΔIHR), fluoride- (F), calcium- (Ca) and phosphorus- (P) concentration in the enamel were determined. Data were analyzed by ANOVA (one-way, repeated measures) and Student-Newman-Keuls test (p < 0.05).

RESULTS

The enamel surface showed greater remineralization (SH2) when treated with 1100F-CPP-ACP-TMP (224.8KHN±1.6) compared to 1100F (163.9KHN±2.0) (p < 0.033). Treatment with 1100F-CPP-ACP-TMP led to remineralization of the subsurface lesion (ΔIHR) by 84 % and 91 % when compared to the 1100F and 1100F-CPP-ACP treatments (p < 0.05). For the F concentration values in the enamel, there was an increase of ⁓ 63 % compared to 1100F (p < 0.05). The Ca concentration in the enamel after 1100F-CPP-ACP-TMP treatment was significantly higher in ⁓ 65 %, ⁓ 28 % and ⁓ 15 % when compared to the 1100F, 1100F-CPP-ACP and 1100F-TMP treatments (p < 0.05). The highest concentration of P was observed for 1100F-ACP-CPP-TMP, which was ⁓ 41 % and ⁓ 17 % higher than the 1100F and 1100F-TMP treatments respectively (p < 0.05).

CONCLUSION

The result of this study demonstrates that the combined use of remineralizing agents (F, CPP-ACP, and TMP) in a single toothpaste formulation (1100F-CPP-ACP-TMP) significantly enhances mineral gain compared to conventional toothpaste, as evidenced by a short-term in situ model.

CLINICAL SIGNIFICANCE

The findings of our study offer essential insights for future investigations and potential clinical applications, especially for individuals with initial caries lesions.

Three-unit CAD/CAM-manufactured lithium disilicate FDPs after an average observation period of 120 months

OBJECTIVE

In recent decades, CAD/CAM-fabricated lithium disilicate restorations have become popular and have been approved for fixed dental protheses (FDPs) up to the second premolar since 2013. This multicenter follow-up study collected long-term clinical data on three-unit anterior and premolar FDPs made of lithium disilicate to evaluate the material's suitability over >10 years.

METHODS

Thirty-two patients received a total of 32 three-unit anterior or premolar monolithic lithium disilicate FDPs. In exceptional aesthetically demanding cases, the labial cut back technique was used for minimal additional veneering. The study was conducted at University Hospital Aachen and three external private dental practices. Failure was defined as any event leading to the loss of an FDP. The survival and success rates were calculated using the Kaplan-Meier method. At the last follow-up examination in 2023 and 2024, 17 of the 32 patients (53,1 %) were re-examined.

RESULTS

The average observation period was 10 years and the longest follow-up period was 15 years. The cumulative survival rate after 10 years was 84.4 %. In detail the five failures recorded were due to one fracture of the connector, one repeated loss of retention, two cases of persistent pain and one loss of an abutment tooth. The cumulative success rate was 75 %.

CONCLUSION

Within the limitations of this study, lithium disilicate for CAD/CAM manufacturing appears to be a reliable material for full-contour three-unit FDPs, provided that the most posterior abutment tooth does not extend beyond the second premolar and that minimum connector thicknesses are maintained. In aesthetically demanding cases, the labial cut back technique combined with additional veneering can be used.

CLINICAL SIGNIFICANCE

This study is one of the few to provide long-term data on the clinical performance of three-unit FDPs made from lithium disilicate, specifically examining cases with premolar abutments. The findings highlight the reliability of this material under the specified conditions.

Exploring the potential of reconstructed human epithelial tissue models for safety assessment of intraoral medical devices

Medical devices are integral to a wide array of medical interventions and are increasingly utilized in both clinical and home settings. Within the oral cavity, intraoral medical devices are employed for various applications, to improve quality of life and maintain oral health and hygiene. However, the dynamic and complex environment of the oral cavity, characterized by the influence of factors, such as saliva composition, fluctuating pH, and microbial flora presents a challenge to ensure the safety of end-users. In this paper, we investigate the feasibility of utilization of 3D reconstructed human tissue models for the assessment of biocompatibility of intraoral medical devices. Building upon experiences drawn from the development and validation of ISO 10993-23 and from the development of a protocol for ocular irritation and photo-irritation, we suggest a new protocol for buccal mucosa irritation testing. The methodology is based on the viability assessment and analysis of cytokine release into media. By addressing intraoral medical devices biocompatibility testing, we aim to contribute to the advancement of biocompatibility assessment methodologies and increase the applicability of ISO 10993-23.

In Vitro Comparison of the Effectiveness of Different Attachment Shapes and Locations on Extrusion of the Upper Left Lateral Incisor Using Thermoplastic Aligners

OBJECTIVES

The aim of this study was to compare the effectiveness of different attachment shapes and locations on the extrusion of the upper left lateral incisor (UL2) using thermoplastic aligners.

MATERIALS AND METHODS

Seven typodonts were digitally printed with hemi-ellipsoid or rectangular attachments in the incisal, middle or cervical third of the UL2. Five clear aligners were fabricated for each typodont; each was tested twice. Forces and moments were measured with an orthodontic force tester during 0.2 mm simulated extrusion of the UL2. Analysis of variance (ANOVA) was used to determine the effects of group, tooth, and the group-by-tooth interaction on the outcomes. A two-sided 5% significance level was used for all tests.

RESULTS

Altering attachment shape and location had a statistically significant effect on the forces and moments generated in each trial (p < 0.01), except for rectangular incisal and hemi-ellipsoid cervical (p > 0.05). The rectangular middle attachment generated the highest extrusive force (Fz = 7.498 N), followed by hemi-ellipsoid cervical (Fz = 6.338 N) and rectangular incisal (Fz = 5.948 N).

CONCLUSIONS

Varying direct attachment shape and location on the UL2 during extrusion has a significant effect on the forces and moments generated by thermoplastic aligners. The rectangular attachment located in the middle third generated the most effective extrusive force and least unwanted moment. For anchorage teeth, hemi-ellipsoid attachments located in the cervical third were found to be the most effective in minimising the reciprocal intrusive forces and unwanted moments.

Racial Disparities in Access to Preventive Dental Services in Pediatric Population: A Secondary Data Analysis

BACKGROUND AND OBJECTIVES

Though preventive measures are available to alleviate the burden of dental caries, there remain racial disparities in the utilization of preventative dental care. Our objectives were to determine whether racial disparities persisted in receiving preventive oral procedures between (1) Black children and white children; and (2) Hispanic children and white children.

METHODS

We used pooled Medical Expenditure Panel Survey data in the United States from 2018 to 2021. The key outcome variable involved the use of preventive dental services (ie, examination, x-rays, cleaning, dental sealant fitting, and fluoride treatment), while the main predictor variable involved race (ie, whether they were white, Black, or Hispanic children).

RESULTS

Controlling for covariates, there was no statistical significance in the odds of Hispanic and white children in receiving x-rays, sealants, and fluoride treatment ( P < .001). Black children had significantly lower odds of receiving oral examination, x-rays, and fluoride treatment than their white counterparts ( P < .01).

CONCLUSIONS

This study highlights the massive strides made in the utilization of preventive dental services by Hispanic children in the United States along with the persisting disparities largely present for Black children; however, further studies are needed focusing on structural, sociocultural, and factors contributing to these disparities.

Effect of beam divergence on the irradiance from dental light curing units

OBJECTIVE

This study measured the beam divergence angle and light output from dental light curing units (LCUs). Twenty LCUs were assessed using a laboratory-grade wide beam imager to determine the relationship between the beam divergence on the irradiance as a function of distance from the light tip.

METHODS

The irradiance (mW/cm2) and beam divergence angles (°) at 5, and 10 mm from the tips of 18 Light-Emitting Diode (LEDs), 1 Quartz-Tungsten-Halogen (QTH), and 1 Laser diode LCU.

RESULTS

There were significant differences in the power, irradiance, and emission spectra from the 20 LCUs. At 10 mm from the LCU tip, the irradiance delivered by one LCU decreased by approximately 85.7 %, whereas this decrease was as low as 5.6 % for a different LCU. There was a positive correlation between the divergence angle reported by the wide beam imager and the reduction in irradiance. The laser diode LCU had the least beam divergence and the smallest decrease in irradiance as the distance increased. In contrast, the QTH LCU with the turbo light guide had the greatest beam divergence and the greatest reduction in irradiance as the distance increased. 50 % of the LCUs tested would require exposure times longer than 20 s to deliver 10 J/cm2 at the 10 mm distance.

SIGNIFICANCE

The wide beam imager is a useful tool for measuring the beam divergence from LCUs and predicting the effect of distance on their irradiance. At 10 mm, some LCUs may require a fivefold increase in the exposure time to deliver the same energy they deliver at 0 mm from the tip of the LCU.

Dydrogesterone alleviates periodontitis in perimenopausal women undergoing periodontal therapy by decreasing inflammation and mediating oral microbiota

OBJECTIVE

Dydrogesterone (DG), a synthetic isomer of progesterone, plays a potential regulatory role in the periodontal environment. The aim of this study was to investigate the potential effects of DG on periodontitis under periodontal therapy (PT) and the underlying mechanisms related to oral microbiota.

METHODS

As a cohort study, perimenopausal women with periodontitis and abnormal uterine bleeding associated with ovulatory dysfunction were screened. A total of 30 women received PT (PT group) and 30 women received PT and oral DG 10 mg twice/day for 10 days/month (PT + DG group). At baseline and 3 months after treatment, pocket probing depth (PPD), bleeding index (BI), bleeding on probing (BOP), plaque index, CRP, IL-6, and TNF-α were measured. Additionally, 16S rDNA sequencing was performed to determine the characteristics of oral microbiota, mainly in terms of abundance, diversity, composition, and community structure.

RESULTS

Three months after treatment, the levels of PPD, BI, and BOP, as well as the levels of CRP, IL-6, and TNF-α in gingival crevicular fluid were significantly lower in the PT + DG group than those in the PT group. After treatment, a relatively lower microbial abundance, and some differences in microbial composition were revealed between the PT and PT + DG groups. At the genus level, significantly fewer Escherichia-Shigella, Porphyromonas, and Absconditabacteriales (SR1), and more Lactobacillus, Gordonia, Bifidobacterium, and Oribacterium were found in the PT group than in the PT + DG group.

CONCLUSIONS

DG enhances the effect of PT on inhibiting inflammatory response in women with periodontitis by mediating oral microbiota.

Accuracy of freehand versus dynamic computer-assisted zygomatic implant placement: An in-vitro study

OBJECTIVE

To compare the accuracy of zygomatic implant placement using a dynamic computer-assisted implant surgery system (D-CAIS) versus the traditional freehand approach.

METHODS

An experimental in vitro study was conducted using 10 stereolithographic models randomized to two groups: D-CAIS (test group) and freehand placement (control group). A single zygomatic implant was placed on each side of the models. The accuracy of implant placement was assessed by superimposing the actual postoperative implant position, obtained via cone-beam computed tomography (CBCT), with the virtual preoperative surgical plan from the preoperative CBCT. Additionally, the operated side and surgery duration were recorded. Descriptive statistics and bivariate analyses were performed to evaluate the data.

RESULTS

The D-CAIS group demonstrated significantly greater accuracy across most outcome variables. Reductions in angular (MD = -5.33°; 95 %CI: -7.37 to -3.29; p < 0.001), coronal global (MD = -2.26 mm; 95 %CI: -2.97 to -1.55; p < 0.001), coronal horizontal 2D (MD = -1.96 mm; 95 %CI: -2.60 to -1.32; p < 0.001) and apical global deviations (MD = -3.37 mm; 95 %CI: -4.36 to -2.38; p < 0.001) were observed. Accuracy in the freehand group varied significantly between operated sides. However, the surgical procedures in the D-CAIS group were significantly longer (MD = 11.90 mins; 95 %CI: 9.37 to 14.44; p < 0.001).

CONCLUSIONS

D-CAIS navigation systems offer significantly greater accuracy in zygomatic implant placement compared to the traditional freehand technique. Additionally, D-CAIS systems may minimize discrepancies in accuracy between operated sides, though their use is associated with an increase in the duration of surgery.

CLINICAL SIGNIFICANCE

D-CAIS navigation systems improve the accuracy of zygomatic implant placement. However, an increase in the duration of surgery is to be expected.

Evaluation of validity and reliability of AI Chatbots as public sources of information on dental trauma

AIM

This study aimed to assess the validity and reliability of AI chatbots, including Bing, ChatGPT 3.5, Google Gemini, and Claude AI, in addressing frequently asked questions (FAQs) related to dental trauma.

METHODOLOGY

A set of 30 FAQs was initially formulated by collecting responses from four AI chatbots. A panel comprising expert endodontists and maxillofacial surgeons then refined these to a final selection of 20 questions. Each question was entered into each chatbot three times, generating a total of 240 responses. These responses were evaluated using the Global Quality Score (GQS) on a 5-point Likert scale (5: strongly agree; 4: agree; 3: neutral; 2: disagree; 1: strongly disagree). Any disagreements in scoring were resolved through evidence-based discussions. The validity of the responses was determined by categorizing them as valid or invalid based on two thresholds: a low threshold (scores of ≥ 4 for all three responses) and a high threshold (scores of 5 for all three responses). A chi-squared test was used to compare the validity of the responses between the chatbots. Cronbach's alpha was calculated to assess the reliability by evaluating the consistency of repeated responses from each chatbot.

CONCLUSION

The results indicate that the Claude AI chatbot demonstrated superior validity and reliability compared to ChatGPT and Google Gemini, whereas Bing was found to be less reliable. These findings underscore the need for authorities to establish strict guidelines to ensure the accuracy of medical information provided by AI chatbots.

Prognostic factors affecting probing depth reduction following non‑surgical periodontal therapy in patients with periodontitis: A linear mixed‑effects model analysis

The present study aimed to elucidate the prognostic factors affecting the probing depth (PD) reduction following the non-surgical periodontal treatment of patients with periodontitis using a linear mixed-effects model. A retrospective analysis was performed on 455 patients who met the specific inclusion criteria. Data were gathered from 3-month re-evaluation records in the electronic periodontal charting system at the Department of Periodontology, School and Hospital of Stomatology at Tianjin Medical University between December 2021 and January 2022. Descriptive statistics were used to assess the changes in PD and certain baseline characteristics of the patients. A three-level nested random-effects mixed-effect model (patient/tooth/site) was used to evaluate the prognostic factors for PD reduction. Variance decomposition was conducted to analyze PD reduction across different nested levels. P<0.05 was considered to indicate a statistically significant difference. The overall mean PD reductions at the patient level for all sites were 0.88 mm. Patients diagnosed with Grade C periodontitis exhibited a greater PD reduction compared with those with Grade B periodontitis (0.96 vs. 0.76 mm; P<0.001). The multivariable coefficient for patients with Grade C periodontitis was 0.20 (95% confidence interval, 0.08-0.33; P<0.001). Random-effects analysis demonstrated that the variability in PD reduction was 59.4, 39.1 and 73.8% at the patient, tooth and site levels, respectively. Grade C periodontitis had the most substantial importance on the effect of PD reduction following NSPT. This reduction in PD could primarily be explained at both the site and patient levels.

Accuracy of various intraoral scanners in scanning post space preparation: An in vitro study

OBJECTIVES

This in vitro study aimed to evaluate the depth, trueness, and scanning time of intraoral scans for post spaces using four different intraoral scanners.

METHODS

A human maxillary canine was decoronated, endodontically treated, and prepared for a post space to a depth of 18 mm. Four intraoral scanners: Primescan (PS), Cerec Omnicam (OC), Medit i700 (MD), and Carestream 3700 (CS), were used to scan the post space (n = 15). A reference scan was obtained using a conventional polyvinyl siloxane impression, which was then scanned with a desktop scanner. All scans were converted to STL files and analyzed in a 3D inspection program to evaluate depth and trueness, measured by root mean square (RMS) calculations. Data analysis involved one-way ANOVA, followed by Bonferroni-adjusted pairwise comparisons.

RESULTS

PS achieved the greatest depth (18.07 mm), followed by MD (9.96 mm), CS (7.31 mm), and OC (7.13 mm), with significant differences observed among the scanners (P < 0.001). Significant differences in RMS values were also found (P < 0.001). The highest RMS value at a depth of 6.5 mm was recorded for OC (31.33 ± 3.44) and CS (30.93 ± 3.65), followed by PS (20.41 ± 3.65), with MD having the lowest RMS value (18.84 ± 3.22). At a depth of 9.5 mm, a significant difference was observed between PS and MD (P < 0.001), with PS showing the lowest RMS value (18.12 ± 2.20) compared to MD (25.80 ± 2.45). Regarding scanning time, PS was the fastest (33.67 s), followed by CS, MD, and OC.

CONCLUSIONS

The PS scanner demonstrated the greatest scan depth, trueness, and the shortest scanning time. In contrast, OC and CS captured the least depth and trueness, limited to 7.1 and 7.3 mm, respectively.

CLINICAL SIGNIFICANCE

The PS scanner is recommended for scanning depths exceeding 10 mm, while the MD is suitable for depths less than 10 mm. OC and CS may be effective for scanning depths limited to 7 mm.

Efficacy of biofilm decontamination methods of dental implant surfaces: A systematic review of in vitro studies

This systematic review examines the decontamination techniques used to clean titanium (Ti) implant surfaces covered with in vitro bacterial biofilms. The selected studies were gathered from the PubMed and Web of Science databases. These include in vitro studies investigating decontamination methods used to clean Ti implant surfaces coated with bacterial biofilms until January 2024. The determined studies were filtered according to the PRISMA guidelines, and the Science in Risk Assessment and Policy (SciRAP) was used to assess the reporting and methodological quality of the included studies. A total of 634 full-length peer-reviewed articles were identified. After excluding duplicate papers between the databases and screening according to the predefined inclusion and exclusion criteria, 13 studies were included. The decontamination methods investigated included mechanical, chemical, and physical methods, either as a single or in a combined approach. Significant variability was observed among the included studies. Combining the mechanical and physical methods with a chemical yielded the most significant reduction in both single- and multiple-species biofilms. The current results do not indicate that any single decontamination technique is more effective than others in eradicating bacterial biofilm from Ti surfaces; the combined approach was more advantageous than the single ones.

A Systematic Review and Meta-Analysis of Interventions Targeted to Parents for Improving the Oral Health of Children from Culturally and Linguistically Diverse (CALD) Backgrounds

A high prevalence of dental caries is a significant health problem, especially in the pediatric population. Low-income minority groups, including the refugee and immigrant populations, are at higher risk of compromised oral health. It has been suggested that migrant parents do not have enough understanding of oral health, risk factors associated with dental caries, or the progress of dental decay. This systematic review aims to study quantitative literature on oral health interventions, health promotion programs, or behaviour change interventions targeting the parents/ caregivers of culturally and linguistically diverse (CALD) children. A systematic search of electronic databases, including MEDLINE, EMBASE, PUBMED, CINAHL, SCOPUS, WEB OF SCIENCE, COCHRANE, and PROQUEST, was conducted until August 2023. Randomised (RCT) or non-randomised controlled trials (NRCTs) were included. Two reviewers independently assessed the quality of the included studies using the Cochrane Risk of Bias (RoB) 2.0 and ROBINS-I tools. Meta-analysis was performed as appropriate. The initial search from the databases retrieved 2073 articles. After the removal of duplicates, 1683 articles remained. Finally, 69 articles were reviewed in full text, and 15 articles were considered eligible in this review. The RoB assessment for RCTs rated three as low-risk and three as high-risk. The serious RoB in these NRCTs mostly pertained to measurement bias based on self-reporting oral health behaviours. The meta-analysis pooling of results (for RCTs and NRCTs) favoured interventions for CALD parents' oral health knowledge [0.73 (95% CI, 0.08 to 1.38) for RCTs, 1.73 (95% CI; 1.45 to 2.02) for NRCTs] and attitudes [0.86 (95% CI, 0.31 to 1.42)]. Relatively high heterogeneity was observed. Oral health educational interventions can be effective in improving the oral health literacy of CALD parents' oral health knowledge and attitudes, especially when facilitated by lay health advisors. However, the low quality of evidence due to high heterogeneity and high RoB further highlighted the need for well-designed RCTs targeting CALD parents.

Your Teeth, You Are in Control: A Process Evaluation of the Implementation of a Cognitive Behavioural Therapy Intervention for Reducing Child Dental Anxiety

AIM

To explore the views of patients, caregivers, and dental professionals on the factors that influence implementation, processes, and effectiveness of a guided self-help cognitive behavioural therapy (CBT) intervention, 'Your teeth, you are in control' (YTYAIC), in the CALM trial.

METHODS

Semi-structured interviews were conducted as part of this qualitative component of the process evaluation, and data were analysed using a framework approach based on the Consolidated Framework for Implementation Research (CFIR) and the Five Areas Model of CBT.

RESULTS

Thirty-seven participants were recruited. Potential mechanisms of action were identified using the Five Areas Model of CBT. Participants felt the intervention may exert change through targeting unhelpful thoughts and feelings (e.g., building trust and perceptions of control) and behaviours (e.g., encouraging effective communication and coping strategies) and facilitating a more positive situational context (e.g., developing more supportive relationships). Enablers (e.g., adaptability, design and delivery) and barriers (e.g., time/resource constraints, cost) to implementation were identified using the CFIR.

CONCLUSIONS

This study revealed multiple potential mechanisms of action which could reduce dental anxiety and examined how implementation and contextual factors may influence this change process. The results of the research revealed that the intervention could be implemented in primary dental care and identified the potential barriers which should be addressed to aid successful implementation of the intervention in real world contexts.

TRIAL REGISTRATION

This clinical trial has been registered with an international registry and has been allocated an International Standard Randomised Controlled Trial Number (ISRCTN27579420).

Accuracy of freehand surgery, static and dynamic computer assisted surgery on zygomatic implant placement: A systematic review and meta-analyses

Real-time surgical navigation systems (dynamic computer-aided surgery, d-CAIS) and static guided surgery (static computer-aided surgery, s-CAIS) have been shown to enhance the accuracy of zygomatic implant (ZI) placement. The objective of this systematic review was to evaluate and compare the accuracy and risk of complications associated with d-CAIS and s-CAIS in ZI placement. A systematic review of published studies involving more than 4 patients was conducted to assess and compare the accuracy of d-CAIS and s-CAIS in zygomatic implant placement. Only one study included freehand ZI placement as a control. The primary outcomes measured were the accuracy of implant placement relative to preoperative planning, with a secondary focus on evaluating any potential complications. Out of 903 screened studies, 14 met the inclusion criteria. Freehand zygomatic implant placement was used as a control in only 1 study. The results revealed a mean apex deviation of 2.07 mm (95% CI: 2.01 to 2.13; I2 = 83.14%) for d-CAIS, 1.29 mm (95% CI: 1.15 to 1.43; I2 = 94.5%) for s-CAIS, and 4.98 mm (95% CI: 3.59 to 6.37; I2 = not assessable) for freehand placement. Reported complications included mucositis, reversible bilateral sinusitis, oroantral fistula, unspecified reversible postoperative complications, and fracture of the anterior wall of the zygoma. Both CAIS systems demonstrated high accuracy and safety in ZI placement, with a nearly 99% success rate at 6 months of follow-up. These findings suggest that both d-CAIS and s-CAIS are reliable methods for improving the precision and reducing the risks associated with ZI procedures.

Stress Distribution in Proclined Anterior Teeth of Pediatric Patients With and Without Mouthguard Use: A 3D Finite Element Analysis

BACKGROUND

Traumatic dental injuries related to sports are a significant concern, as they can have severe physical and psychological impacts on children. Using mouthguards is essential, particularly in sports like skating, where high-impact forces are common.

AIM

The study aimed to evaluate how stress is distributed on the teeth and surrounding bone in children with proclined anterior teeth when a force of 614.12 N was applied to two different regions of the jaws. The evaluation was conducted using finite element analysis (FEA), both with and without the use of a mouthguard.

METHODS AND METHODOLOGY

A 3-dimensional finite element analysis (FEA) model was constructed using a cone beam computed tomography (CBCT) scan of a 12-year-old male patient. An average standardized force of 614.12 N was calculated, based on the average weight of children aged 11 to 13 years and the average speed of 13.4 m/s with which the children skate. The force was applied in two different directions and areas of the jaws: a lateral blow, perpendicular to the crown and root with the maxillary and mandibular teeth in occlusion (between the first molar and second premolar), and a blow obliquely at the pogonion point on the chin. Static simulations were then performed for four realistic scenarios-two with mouthguards and two without mouthguards.

RESULT

The Von Mises stresses were evaluated under all conditions. When the applied force was directed laterally, the stress values observed were 126.76 MPa with a mouthguard and 140 MPa without a mouthguard. When the force was applied to the chin region, the stress values were 37.997 MPa with a mouthguard and 40.67 MPa without a mouthguard.

CONCLUSION

The use of a mouthguard in children is beneficial for protecting teeth and surrounding structures, especially in cases of proclined anterior teeth, as it helps dampen the generated stresses.

Experimental bilayer zirconia systems after aging: Mechanical, optical, and microstructural characterization

OBJECTIVES

To characterize two experimental zirconia bilayer materials compared to their monolithic controls, before and after hydrothermal aging.

METHODS

Commercial zirconia powders were utilized to fabricate two bilayer materials: 3Y-TZP+ 5Y-PSZ (3Y+5Y/BI) and 4Y-PSZ+ 5Y-PSZ (4Y+5Y/BI), alongside control groups 3Y-TZP (3Y/C), 4Y-PSZ (4Y/C), and 5Y-PSZ (5Y/C). Compacted specimens were sintered (1550 °C- 2 h, 3 °C/min), and half of them underwent hydrothermal aging (134 °C-20h, 2.2 bar). Characterizations were performed through scanning-electron microscopy (SEM), X-ray diffraction (XRD), Raman spectroscopy, reflectance tests and biaxial flexural strength test (ISO:6872). Weibull statistics were applied to determine the characteristic strength and Weibull modulus. Grain size and optical properties were analyzed using two-way ANOVA followed by the Tukey test.

RESULTS

Degradation regions and monoclinic phase were observed at aged 3Y-TZP and 4Y-PSZ surfaces. Significant differences were observed in the evaluation of optical properties between the bilayer and control groups. The bilayer materials presented intermediate characteristic strength values compared to their controls and aging significantly increased the strength of some groups.

SIGNIFICANCE

Experimental bilayer materials presented lower mechanical properties than monolithic controls, 3Y/C and 4Y/C. Hydrothermal aging increased the characteristic strength of bilayered and monolithic controls, except for 5Y-PSZ. Both experimental bilayer systems, as well as monolithic controls, met the ISO 6872:2015 requirements for single-unit crowns (100 MPa), 3-unit fixed dental prostheses (FDPs) up to premolars (300 MPa), and 3-unit FDPs involving molars (500 MPa). However, for FDPs with four or more units, only monolithic 3Y-TZP and 4Y-PSZ, and bilayered 3Y+5Y met the required minimum flexural strength (≥800 MPa).

Clinical outcomes of novel CAD/CAM-designed functional space maintainers produced via additive and subtractive methods: A randomized controlled trial

OBJECTIVE

Since passive fixed space maintainers do not restore the lost tooth or provide chewing function, this study seeks to assess the effectiveness of an innovative approach for maintaining space following the premature extraction of first primary molars, utilizing functional space maintainers designed with CAD/CAM.

METHODS

This randomized controlled trial included 28 patients allocated into two groups (15 in 3D Printing group and 13 in Milling group). The inclusion criteria required extraction or loss of the first primary molar due to complications of caries, with a prolonged period until eruption of the successor. Space maintainers were fabricated using 3D printing metal (Co 69 %, Cr 25 %, W 9.5 %, Mo 3.5 %, Si 1 %, Scheftner, Germany) and milling composite (breCAM.HIPC, Bredent, Germany). This study evaluated the efficiency of space maintainers through clinical check-ups at one, three, and six months, maximum occlusal bite force, and masticatory performance assessments.

RESULTS

A positive clinical trend was noted over time, with the "type of space maintainer" factor (Milling vs. 3D Printing) influencing the degree of clinical assessment (p < 0.001). There were no significant differences in maximum occlusal bite force between sides for both types of space maintainers (p = 0.270 for 3D Printing and p = 0.765 for Milling). Significant improvements were observed in masticatory performance after the placement of both types of space maintainers.

CONCLUSION

A six-month follow-up showed that 3D-printed metal outperformed milled composite ones, with no significant differences in bite force or masticatory performance, indicating that CAD/CAM technology could set new standards in producing functional space maintainers.

CLINICAL SIGNIFICANCE

This study underscores the potential of the manufacturing technologies to set new standards in pediatric dentistry, particularly for maintaining space following premature tooth loss, while ensuring improved functional outcomes for young patients.

Dental plaque-inspired peptide engineered to control plaque accumulation

Effective control of plaque accumulation is an important strategy for reducing the risk of both localized oral health issues and systemic diseases associated with plaque. However, existing approaches for preventing plaque accumulation exhibit some limitations, such as insufficient compatibility with the oral microbiota and tissues, as well as inconvenience in their use. Herein, inspired by dental plaque, a new class of peptides featuring excellent anti-fouling performance is successfully developed. Our peptides consist of a salivary-acquired peptide with tooth surface-selective adhesion, a zwitterionic peptide with anti-adhesion property, and four proline residues that provide structural rigidity. We conduct a series of progressive experiments, including molecular dynamics simulation and assessments of the anti-fouling performance of our peptides on hydroxyapatite slices, human tooth enamel slices, and ex vivo human teeth. The results demonstrate that our peptides possess the abilities of rapid anchoring on tooth surfaces and effective inhibiting protein and bacterial adhesion. These characteristics enable our peptide to efficiently control plaque accumulation through rinsing or spraying while preserving the balance of the oral microbiota. These findings open an appealing avenue for the development of anti-fouling agents for controlling plaque accumulation on tooth surfaces.

The Mechanical Properties of Orthodontic Aligners of Clear Aligner After Intraoral Use in Different Time Periods

OBJECTIVE

Although the technique of orthodontic aligners has risen in popularity, their mechanical properties have not been thoroughly investigated. The aim of this study was to evaluate the mechanical properties of the orthodontic aligners Clear Aligner after intraoral use for 7, 10 and 14 days, and to compare them with as-received aligners (0 days). It was also sought to examine the properties of the unprocessed raw material (polyethylene glycol terephthalate) used to manufacture these aligners.

MATERIALS/METHODS

Thirty-two aligners by four patients were evaluated and studied at 0, 7, 10, 14 days of use. Each aligner was divided into three segments (two posterior and one anterior), which resulted in 96 samples. Also, 16 samples of unprocessed material were studied. For all samples, elastic modulus, ultimate tensile stress (UTS) and yield stress were calculated by conducting tensile testing. Additionally, material hardness was tested. The two-tailed Mann-Whitney test was performed, having set the level of significance at p = 0.05.

RESULTS

Analysis of the measurements indicated a statistically significant decrease in elastic modulus between days 0 and 14 of use, of UTS between days 0 and 7, 7 and 10, and of yield stress between days 0 and 7. For hardness, in every period, posterior segments demonstrated significantly higher values than anterior segments. All properties of the unprocessed material were statistically significantly higher than the processed samples.

CONCLUSIONS

The unprocessed material presented significant differences in every property tested in comparison to the processed aligners. The processed material showed further deterioration over time during use. The present study provides evidence that thermoforming and ageing affect the mechanical properties of the aligners.

Effect of nitrogen atmosphere during 3D printing on mechanical properties of orthodontic aligners

The aim of this study was to investigate the effect of low oxygen environment during printing on the mechanical properties of 3D printed aligners. Thirty-six 3D printed rectangular (20 × 20 × 10 mm) specimens were fabricated using the SprintRay Pro 55 printer and equally divided into two groups. Eighteen of them were built under normal atmosphere conditions during printing (CON) and the rest by continuously purging pure (NIT), thereby eliminating the oxygen content. Both groups underwent post-curing in an illuminated chamber. Three samples from each group were analyzed by attenuated total reflection Fourier-transform infrared spectroscopy (ATR-FTIR). The remaining specimens underwent metallographic grinding/polishing followed by nano-indentation testing. The mechanical properties measured were: Martens Hardness (HM), indentation modulus (EIT), and elastic index (ηIT). Statistically significant differences between groups were assessed using Mann-Whitney tests (α = 0.05). Both groups showed identical ATR-FTIR spectra and complete C = C conversion. No statistically significant differences in the parameters tested were seen. The medians (interquartile ranges) were HM CON: 68.0 N/mm2 (65.0-71.0 N/mm2), NIT: 73.0 N/mm2 (67.0-83.0 N/mm2); EIT CON: 1999.0 MPa (1952.0-2154.0 MPa); NIT: 2047.0 MPa (1702.0-2104.0 MPa); ηIT CON: 28.0% (27.2%-29.0%) and NIT: 28.9% (27.1%-31.4%). The results of this study showed that elimination of oxygen during printing does not affect the mechanical properties of 3D printed aligners.

Changes in the caries-associated microbiota and caries experience in children and adolescents with type 1 diabetes: A systematic review and meta-analysis

OBJECTIVE

This systematic review aimed to determine the differences in the caries-associated microbiota and caries experience among children with type 1 diabetes (T1D) compared to healthy children in observational studies.

DESIGN

Registered in PROPSERO (CRD42024529842), this review involved searching four electronic databases (PubMed, Embase, Scopus and Web of Science) from inception to April 2024. Citation searching was further performed on eligible studies from the database search. Observational studies comparing the cariogenic taxa between paediatric participants (0-18 years of age) with T1D and healthy paediatric participants were included. Caries experience was analysed where available in eligible studies. Outcomes were narratively and tabularly synthesised, and meta-analysis performed where appropriate. All studies were critically appraised using the relevant Joanna Briggs Institute appraisal tool.

RESULTS

425 studies were identified, of which 14 studies were eligible. After assessing 534 citations, 2 additional studies were included. Overall, 16 studies (15 cross-sectional, 1 longitudinal) satisfied the inclusion criteria. Differences in cariogenic bacteria were observed when glycaemic control was considered. Children with T1D and poorer glycaemic control exhibited an increase in Streptococci and Lactobacilli taxa compared to those with improved glycaemic control and healthy children. A small number of studies also found increases in the caries experience with poorer glycaemic control.

CONCLUSION

Overall, the evidence indicates that children with T1D who have poorer glycaemic control exhibit an increase in cariogenic bacteria. Early evidence suggests that these children also experience more caries. However, further research with improved and longitudinal study designs are required to strengthen the existing evidence.

Psychosocial Determinants of Poor Dental Attendance Among Young Mexican-Identifying Adults in California

OBJECTIVE

Engagement in preventive dental care is a complex health behaviour and is determined by multiple factors. The study aimed to understand the association of psychosocial determinants with poor dental attendance.

METHODS

Survey data from 333 Mexican-identifying adults in California aged 21-40-year were analysed. Poor dental attendance was a composite of time since last dental visit and reason for visit. Responses of 'more than 1 year ago' for last dental visit, or 'something was wrong, bothering or hurting/emergency dental problem' as the reason for last dental visit were categorised as poor dental attendance. Psychosocial determinants including dental anxiety assessed using the Modified Dental Anxiety Scale, participant reported quality of provider interactions, and perceived social support were assessed. Logistic regression analyses examined associations after accounting for covariates.

RESULTS

Over half (58%) had poor dental attendance. Among those with poor dental attendance, 22% had high dental anxiety, 41% perceived low quality of dental explanation, and 48% reported provider occasionally/never checked patient understanding. Participants with high anxiety had twice the odds of poor dental attendance (OR = 2.07, 95% CI = 1.01-4.22) than those with low dental anxiety. Additionally, those reporting that providers did not explain oral health status or treatments well had two times higher odds of poor dental attendance than those reporting adequate explanation (OR = 2.06, 95% CI = 1.11-3.83). Checking patient understanding or perceived social support was not significantly associated with dental attendance.

CONCLUSION

Dental anxiety and poor provider interactions affect use of dental services. Interventions targeting dental staff should prioritise enhancing communication skills and checking patient understanding to improve their dental attendance.

ZygoPlanner: A three-stage graphics-based framework for optimal preoperative planning of zygomatic implant placement

Zygomatic implant surgery is an essential treatment option of oral rehabilitation for patients with severe maxillary defect, and preoperative planning is an important approach to enhance the surgical outcomes. However, the current planning still heavily relies on manual interventions, which is labor-intensive, experience-dependent, and poorly reproducible. Therefore, we propose ZygoPlanner, a pioneering efficient preoperative planning framework for zygomatic implantation, which may be the first solution that seamlessly involves the positioning of zygomatic bones, the generation of alternative paths, and the computation of optimal implantation paths. To efficiently achieve robust planning, we developed a graphics-based interpretable method for zygomatic bone positioning leveraging the shape prior knowledge. Meanwhile, a surface-faithful point cloud filling algorithm that works for concave geometries was proposed to populate dense points within the zygomatic bones, facilitating generation of alternative paths. Finally, we innovatively realized a graphical representation of the medical bone-to-implant contact to obtain the optimal results under multiple constraints. Clinical experiments confirmed the superiority of our framework across different scenarios. The source code is available at https://github.com/Haitao-Lee/auto_zygomatic_implantation.

Evaluating the influence of sports-induced trauma on temporomandibular disorders: A systematic review and meta-analysis

OBJECTIVE

The main aim of this study was to identify the existing literature on the association between sporting activities and temporomandibular disorders and to critically appraise evidence of this association through a systematic review and meta-analysis.

DESIGN

A comprehensive search was conducted using PubMed, ScienceDirect, Dimensions, Google Scholar, Cochrane Library, and the Education Resources Information Centre (ERIC). Articles were selected using pre-specified eligibility criteria. In addition, the quality of eligible studies was assessed using the National Institutes of Health (NIH) for observational cohort and cross-sectional studies. Data were systematically extracted and analyzed.

RESULTS

Temporomandibular disorder symptoms, such as myofascial pain, clicking sounds, and musculoskeletal symptoms, were comparably prevalent among athletes and non-athletes, with some studies reporting contrasting results. However, meta-analyses of the comparisons demonstrated statistically insignificant differences between athletes and non-athletes. Additionally, there was a significant reduction in temporomandibular disorder symptoms when mouthguards were used.

CONCLUSIONS

This comprehensive analysis of existing evidence highlights the various symptoms and clinical manifestations of TMD among athletes, including myofascial pain, clicking sounds, and musculoskeletal symptoms. This study established different prevalence rates in different sports.

Effect of manufacturing trinomial and restoration thickness on the fabrication trueness, fit, and margin quality of additively manufactured resin-based ultrathin laminate veneers

OBJECTIVE

To evaluate the effect of the manufacturing trinomial (manufacturing technology, three-dimensional printer, and material) and restoration thickness on the fabrication trueness, fit, and margin quality of additively manufactured resin-based ultrathin laminate veneers (LVs) by comparing to those produced subtractively.

METHODS

Reference LVs were designed from the scan files of two identical maxillary central incisor typodonts prepared for 0.3 mm and 0.5 mm LVs. LVs were manufactured additively with resins of different compositions, either using a tilting stereolithography (Irix Max [AM-IX] and Irix Plus [AM-IP]) or a digital light processing printer (VarseoSmile Crown Plus [AM-VS] and Tera Harz TC- 80DP [AM-GR]), and subtractively (Tetric CAD [SM-TC]) (n = 10). All LVs were digitized to evaluate their fabrication trueness and fit. The margin quality was assessed through visual examination. The trueness and fit data were analyzed with two-way analysis of variance and Tukey tests, while the chi-squared test was used to evaluate the margin quality (α = 0.05).

RESULTS

The interaction between the main factors and the manufacturing trinomial affected the fabrication trueness and fit, while restoration thickness affected the fit of tested LVs (P ≤ 0.001). AM-IP mostly had the lowest deviations, followed by AM-IX, and mostly had the lowest gaps (P ≤ 0.037). Thinner LVs had lower gaps (P < 0.001). Tested LVs mostly had slightly rough margins with small defects.

CONCLUSIONS

LVs fabricated with the tilting stereolithography printer mostly had higher trueness. Using AM-IP or fabricating 0.3 mm LVs improved the fit. Nevertheless, all tested LVs had clinically accep fit.

CLINICAL SIGNIFICANCE

Ultrathin laminate veneers fabricated with the manufacturing trinomial involving tested tilting stereolithography printer and resins may require less clinical adjustments. In addition, one of the resins (AM-IP) within this manufacturing trinomial or fabricating 0.3 mm laminate veneers may improve the fit.

Prevalence of hypodontia and other developmental dental anomalies in children with or without molar incisor hypomineralisation

OBJECTIVES

To investigate whether hypodontia and other developmental dental anomalies were more common in children with MIH than their unaffected peers, and to determine if sex or geographical location had any effect on hypodontia prevalence.

METHODS

This analytical cross-sectional study was conducted in specialist paediatric dentistry clinics across 14 countries, categorised into six geographical regions. A total of 1279 children (aged 6 - 17 years) underwent a clinical examination and were allocated to the MIH (n = 649) or comparison group (n = 630). A validated MIH index was used to record the presence/extent of any hypomineralisation and a standardised approach was used to establish the clinical and/or radiographic presence of ten developmental dental anomalies.

RESULTS

Four anomalies were significantly more prevalent in participants with MIH than those without this condition: hypodontia (p = 0.047), dens invaginatus (p = 0.004), dens evaginatus (p < 0.001) and microdont maxillary lateral incisors (p = 0.01). Additionally, the adjusted odds of hypodontia were 1.49 times higher in children with MIH compared to those without MIH. There was considerable disparity between geographic locations with the highest prevalence of hypodontia in participants from the Western Pacific region (11.21 %) and the lowest (2.92 %) in the Americas. No statistically significant association was found between sex (male vs. female) and hypodontia (p = 0.839).

CONCLUSIONS

Accepting that the study group may not be representative of the wider population, the findings still have important clinical relevance. Furthermore, they lend support to the concept of shared genetic and epigenetic influence in the aetiology of MIH and other developmental dental disorders.

Long-term structural and functional nasomaxillary evolution of children with mouth-breathing after rapid maxillary expansion: An 8-year follow-up study

Objective

To evaluate the effects of rapid maxillary expansion (RME) on nasal patency and nasomaxillary dimensions in children and adolescents with mouthbreathing through 8 years of clinical follow-up.

Methods

RME was performed using a Hyrax orthodontic appliance in 28 mouth-breathers (6-13 years old). During follow-up, objective tests of nasal respiratory function were conducted, such as acoustic rhinometry, which provided the minimum cross-sectional areas of the nasal cavity, and active anterior computed rhinomanometry, which measured inspiratory nasal resistance. The tomographic widths of the coronal sections of the nose and maxilla were also measured. Fisher's exact test and the Mann-Whitney U test were used to compare categorical and numerical variables, respectively, in mouth-breathers with and without allergic rhinitis. Temporal evolution was assessed using generalized estimating equation models. Statistical significance was set at P < 0.05.

Results

There was a reduction in inspiratory resistance after RME with a stable improvement in nasal patency during the 8-year follow-up period (P = 0.0179). All nasal and maxillary tomographic widths showed statistically significant increases in the short-term (P < 0.0001), and most of them showed significant increases in the long-term when compared with the pre-expansion period. Tomographic measurements were not influenced by allergic rhinitis.

Conclusions

Our study showed that RME promoted and maintained the widening of the posterior maxillary structure in children and adolescents with mouth-breathing, with a decrease in inspiratory nasal resistance during the 8-year follow-up period. These findings highlight the importance of RME in mouth-breathers with maxillary atresia.

Impact of malocclusion on oral health-related quality of life: insights from children with and without hypodontia

OBJECTIVE

To assess the impact of malocclusion on oral health-related quality of life (OHRQoL) and to compare the impact of malocclusion in children with and without hypodontia.

METHODS

Children aged 10-16 years with ≥ 5 missing teeth and without hypodontia completed the Malocclusion Impact Questionnaire (MIQ) to assess the impact of malocclusion on OHRQoL. The Child Perception Questionnaire 11-14 years short form (CPQ11-14-ISF16) was used to verify the validity of the MIQ. Demographic and orthodontic data were collected. Internal consistency and validity of the MIQ were analyzed. MIQ scores were compared using an independent t‑test. Regression analysis was performed to identify predictors of the MIQ score.

RESULTS

A total of 92 participants completed the MIQ, and 52 participants the CPQ11-14-ISF16. The MIQ showed excellent internal consistency (Cronbach's α 0.89) and good criterion validity with CPQ11-14-ISF16 (r = 0.58). No significant difference in the impact of malocclusion on OHRQoL between the groups (p = 0.15) was found. Age (p < 0.05), sex (p < 0.001), and general appearance (p < 0.001) significantly predicted OHRQoL scores in the regression analysis. Multilevel analysis showed that the group and age effects were nonsignificant and that sex and general appearance were predictive for the MIQ score.

CONCLUSION

This study suggests that the MIQ is a useful tool to assess the impact of malocclusion on OHRQoL in the orthodontic field. Differences in the impact of malocclusion on OHRQoL between children with and without hypodontia of ≥ 5 teeth were limited. It may be beneficial delaying treatment until the patient expresses a subjective treatment need which may reduce overtreatment of children with hypodontia.

Biocompatibility of irrigation solutions to dental-derived mesenchymal stem cells in regenerative endodontic procedure: a systematic review of in vitro studies

Regenerative endodontic procedures (REPs) offer an alternative to apexification in necrotic immature permanent teeth, promoting continued root development and dentinal wall thickening. Success in REPs requires effective disinfection and the survival of dental-derived mesenchymal stem cells (DMSCs), such as dental pulp stem cells (DPSCs), stem cells from the apical papilla (SCAPs), and periodontal ligament stem cells (PDLSCs). This review investigates the biocompatibility of irrigation solutions, including sodium hypochlorite (NaOCl), ethylenediaminetetraacetic acid (EDTA), and chlorhexidine (CHX), on DMSCs. Following PRISMA guidelines, a comprehensive search was conducted in PubMed, Scopus, Web of Science, Cochrane, and SciELO, with the last update on March 4, 2024. Studies from January 2008 to April 2024 assessing viability, proliferation, migration, differentiation, and mineralization of DMSCs treated with NaOCl, EDTA, and CHX were included. The papers were selected using PICOS criteria and quality was assessed using the PRILE checklist and risk of bias with the Quality Assessment Tool for In Vitro Studies. Of 738 studies identified, 15 met inclusion criteria. The findings suggest that NaOCl and CHX exhibit lower biocompatibility towards DMSCs compared to EDTA. NaOCl and CHX are cytotoxic to DMSCs, while EDTA demonstrates favorable biocompatibility, promoting osteogenic differentiation and mineralization. This highlights potential implications for irrigant selection in regenerative procedures, as appropriate irrigants may enhance cellular survival and improve clinical outcomes.

The association of third molars with mandibular incisor crowding in a group of the Yemeni population in Sana'a city: cone-beam computed tomography

BACKGROUND

Multiple factors contribute to mandibular incisor crowding. However, the role of wisdom teeth in these irregularities remains a controversial issue among clinicians. Therefore, this study aimed to determine the potential association between mandibular incisor crowding and the presence or absence of lower wisdom teeth using CBCT image analysis.

MATERIALS AND METHODS

A total of 64 CBCT images of adult patients were recruited. These CBCT images were classified into two groups according to the presence or absence of the lower wisdom teeth on the panoramic view. After the classification, the severity of crowding was calculated by utilizing Little's irregularity index. Points such as A point, Nasion, and B point (Supramentale) were identified on the software program. The significance level was set at P < 0.05.

RESULTS

There was no statistically significant correlation (P = 0.780) in the crowding of the mandibular incisor among the groups with the presence or absence of the lower wisdom teeth. Group 1 (with wisdom teeth) was 5.85 ± 4.05 mm, classified as a moderate irregularity; similarly, group 2 (without wisdom teeth) showed moderate irregularity with a mean value of 5.32 ± 3.12 mm. There was an incisor crowding with a severe irregularity in 18 patients (28.1%), a minimal irregularity in 15 patients (23.4%), a moderate irregularity in 14 patients (21.9%), a very severe irregularity in 10 patients (15.6%), and a perfect alignment in 7 patients (10.9%).

CONCLUSIONS

The presence and absence of lower wisdom teeth do not influence the mandibular incisor crowding.

Are Orthodontic Interventions Associated With Headaches in Children and Adolescents? A Systematic Review and Meta-Analysis

This study aimed to assess the prevalence of headaches in children and adolescents during and after completing orthodontic treatment. This systematic review followed the PRISMA guidelines. An extensive literature search was conducted in the following databases: MEDLINE, Embase, CINAHL, Web of Science, and Cochrane from inception until December 20, 2024. Studies targeting individuals between 7 and 18 years old, diagnosed with malocclusions, and receiving orthodontic treatment were included. A meta-analysis (odds ratio) was performed considering the number of individuals with and without headache, who did and did not undergo orthodontic treatment. The quality of studies was assessed using the Quality in Prognosis Studies (QUIPS) tool. Finally, the overall certainty of the evidence was assessed by the GRADE approach. Seven studies met the inclusion criteria with a pooled sample size of 1.141 individuals. No statistically significant difference in the prevalence of headache was found between children who received orthodontic intervention compared to no treatment (OR 1.22 [CI 0.78; 1.92]; p = 0.38). Children with malocclusion who were treated orthodontically had significantly fewer headaches after treatment compared to untreated children with class II malocclusion (OR 0.42 [CI 0.19; 0.92]; p = 0.03). All studies had a high risk of bias, and the certainty of evidence was very low. In summary, no increased prevalence of headaches was detected during or after orthodontic interventions in children and adolescents with malocclusions when compared to those who did not receive orthodontic treatment. Instead, children with malocclusion treated orthodontically had significantly fewer headaches after treatment compared to untreated children with malocclusion. Further research is needed, as the conduct and quality of the existing studies need substantial improvement. Trial Registration: CRD42022340817 (PROSPERO).

Proton-Nuclear Magnetic Resonance Metabolomics of Gingival Crevicular Fluid During Orthodontic Tooth Movement With Aligners

OBJECTIVES

To determine the correlation between orthodontic tooth movement and a pre-defined set of gingival crevicular fluid (GCF) metabolites through proton nuclear magnetic resonance (1H-NMR) spectroscopy.

MATERIALS AND METHODS

A clinical randomised prospective split-mouth study comparing the GCF metabolites around stationary and moving second maxillary molars. Twenty-four healthy subjects diagnosed with dental class II malocclusion undergoing orthodontic clear aligner treatment (CAT) were enrolled. GCF samples from the mesial and distal sulcus of second molars under stationary conditions or under 1 N of distalising force were harvested at baseline, 1 h, 7 days and 21 days after the application of CAT. 1H-NMR was utilised for GCF sample analysis. The 2-dimensional total correlation spectroscopy spectral signature of 35 known GCF metabolites was compared in moving and stationary teeth. Principal component analysis (PCA), partial least squares-discriminant analysis (PLS-DA), variable importance in projection (VIP) score and area under the curve (AUC) were computed utilising MetaboAnalyst 5.0 software.

RESULTS

VIP-score values showed statistically significant differences between the metabolites involved in moving and stationary molars (p < 0.05). PCA and PLS-DA results showed potential differences between the metabolite clusters. The variation of the 1H-NMR signals of Glutamine, Uracil, N-Acetylneuraminate and alpha-ketoglutarate contributes primarily to the variance across metabolites in moving versus stationary teeth at 1 h, 7 days and 21 days.

CONCLUSION

High values of Glutamine and low values of Uracil, N-Acetylneurinamate and alpha-ketoglutarate could be utilised to predict the progress of orthodontic tooth movement over time. Knowledge of metabolites predictive of tooth movement could contribute to the design of tailored orthodontic treatment planning, reducing time, costs and side-effects.

Patient-Reported Outcomes With Immediate-Loaded Zygomatic Implant Fixed Rehabilitation in Patients With Edentulous Atrophic Maxilla: A Retrospective Practice-Based Clinical Study

OBJECTIVE

To assess if immediate-loaded zygomatic implant-supported fixed rehabilitation meets the expectations of and satisfies patients with atrophic edentulous maxilla.

METHODS

This study included an analysis of data obtained from the dental records of 22 consecutive patients with atrophic edentulous maxillae who received immediate-loaded zygomatic implant-supported fixed rehabilitation between 2017 and 2020. Patients' expectations and satisfaction scores were recorded on a validated 100-mm visual analog scale (VAS). Data was analysed using descriptive statistics and generalized estimating equations.

RESULTS

The results showed a majority of patients had high expectations (VAS > 90) of the rehabilitation with regard to their general satisfaction (71%), aesthetics (71%), chewing (66%), speech (66%), and influence on social life (81%). At 6 months, a majority of the patients showed high general satisfaction (72%), and high satisfaction with aesthetics (77%), chewing (72%), speech (66%), and social life (72%) (VAS > 90). There was a statistically significant increase in the level of satisfaction with chewing from 2 weeks to 6 months after immediate loading (B = 0.309, SE = 0.138, 95% CI: 0.038, 0.580, p = 0.025). A statistically significant association was found between pre-treatment expectations and satisfaction with the rehabilitation's impact on speech, aesthetics, and social life. The satisfaction levels were not influenced by age and sex. All participants agreed that they would recommend this procedure to their peers.

CONCLUSIONS

The results of this study suggest that immediate-loaded zygomatic implant-supported fixed rehabilitation could meet the expectations and satisfy edentulous patients with atrophic maxilla.

Antimicrobial effect of blue light on antibiotic-sensitive and drug-resistant Escherichia coli: a novel isotropic optical fibre

Background. Orthopaedic oncological pelvic reconstructions have an elevated risk of infection with Gram-negative bacteria. This study evaluates the bactericidal ability of a novel antimicrobial blue light (ABL)-emitting optical fibre on antibiotic-sensitive Escherichi coli (AS-Ec) and ESBL-producing E. coli (ESBL-Ec). Methods. Time-to-kill assays used a 10 ml NaCl solution with a starting inoculum of 1×105 c.f.u. ml-1 for AS-Ec or ESBL-Ec; assays were repeated at least three times per strain. Experimental tubes had either one optical fibre [20.1 mW mm-1; low power (LP)] or two optical fibres [40.3 mW mm-1; high power (HP)], which delivered five wavelengths of ABL over 60 min. Control tubes had no optical fibres. Fifty microlitres of samples taken from each tube at 0, 10, 20, 30 and 60 min were streaked onto agar plates and incubated. c.f.u. ml-1 was determined. Bactericidal reduction was defined as a 99.9% (≥3 log10) reduction in c.f.u. ml-1. One-way ANOVA was conducted. Results. Bactericidal effects were seen for AS-Ec under both LP-ABL and HP-ABL with a log10c.f.u. ml-1±sd difference of 3.44±0.35 (P=0.043) and 3.74±0.21 (P=0.048) at 30 and 20 min, respectively. For ESBL-Ec, while there was a significant reduction in bacterial colony formation, the bactericidal threshold was not reached with a log10c.f.u. ml-1±sd difference of only 1.02±0.41 (P=0.034) and 2.53±0.22 (P=0.037) at 60 min for LP-ABL and HP-ABL, respectively. Conclusions. A novel ABL-emitting optical fibre exhibited bactericidal effects in AS-Ec and a clinically meaningful reduction of ESBL-Ec, providing a promising avenue for the use of ABL as a potential therapy for Gram-negative infections.

Assessing socioeconomic status through dental and associated tissue characteristics: A cross-sectional study for human identification

Background

Dental identification methods are employed to determine a person's identity in forensic odontology. Additionally, analyzing a person's teeth can provide insights into their socioeconomic status, which may assist in the process of identification. Our study aimed to assess the correlation between dental health status and SES among individuals, with a focus on identifying predictors of SES based on dental health indicators.

Methods

A cross-sectional study was conducted to evaluate the correlation between dental health status and socioeconomic status among 135 individuals. who had visited the Department of Oral Medicine for various forms of dental care. SES was measured according to a modified Kuppuswamy scale. The associations between SES and dental health indicators were analyzed using chi-square tests for categorical variables and t-tests for continuous variables.

Results

Dental caries is more common in lower SES groups, attributed to factors like poor nutrition and hygiene. Partial and complete edentulism are also more prevalent in lower SES populations, often due to financial constraints and lack of awareness, leading to extractions rather than restorations. However, urban populations, regardless of SES, show greater utilization of dental restorations, likely due to the concentration of dentists in cities and access to community-based dental camps offering low-cost treatments. Periodontal diseases further reflect SES disparities. Studies show that individuals from lower SES backgrounds report more severe periodontal issues, such as gingival swelling, while higher SES groups report milder symptoms like gingival bleeding, indicating earlier intervention.

Conclusion

SES plays a vital role in shaping health and lifestyle outcomes. The findings in our study demonstrate the value of incorporating SES indicators, such as education, occupation, marital status, and residence, into forensic investigations to enhance the precision of identification processes.

Learning needs of residents in oral and maxillofacial surgery outpatient clinics: a dual-source survey study

BACKGROUND

Standardized residency training for dental residents is a clinical skills development program designed for newly graduated dental students. A significant conflict arises between patients' expectations for high-quality medical services and residents' need to enhance their skills through hands-on clinical practice. This study aims to explore the current situation and needs of resident doctors in the outpatient department of oral and maxillofacial surgery, based on patient dissatisfaction feedback and a comprehensive questionnaire survey among resident doctors.

METHODS

Dissatisfaction feedback related to the oral and maxillofacial surgery outpatient clinic from 2021 to 2023 was collected, categorized, and analyzed. Concurrently, a survey questionnaire comprising 19 questions was designed to assess the the residents' current work status and needs of in the outpatient department. The questionnaire was completed by the residents and analyzed to gather insights.

RESULTS

From 2021 to 2023, there were 84 instances of dissatisfaction feedback involving resident doctors in the oral and maxillofacial surgery outpatient clinic. The primary reason for dissatisfaction was "severe postoperative reactions" (42.9%), followed by "resident doctors unable to solve problems independently" (26.2%), and "patients' lack of trust in resident doctors" (25%). The resident doctor questionnaire yielded 71 valid responses, revealing that the main factor hindering their ability to consult patients was patients' distrust (42.25%), followed by "lack of confidence and fear of causing adverse effects" (36.62%). Residents rated their theoretical knowledge and practical abilities at 2.75 and 2.86, respectively, indicating moderate proficiency levels. They identified increased clinical consultation opportunities as their most critical need to improve diagnostic and treatment skills (77.5%). Their preferred consultation modes were: [1] operating independently with the teacher observing and summarizing afterward (56.34%), and [2] operating independently with the teacher observing and providing real-time reminders during the operation (23.9%).

CONCLUSION

In the outpatient department of oral and maxillofacial surgery, the primary reasons for patient dissatisfaction related to resident doctors are inadequate operational skills and patients' distrust in their abilities. However, due to the limited sample size of this study, the generalizability of these findings to a broader population remains uncertain. Further large-scale, objective investigations are needed to provide clearer and more meaningful insights into this issue.

Effect of environmental conditions on wear resistance of lithium silicate glass-ceramic materials

OBJECTIVES

To compare the impact of neutral and acidic environments on wear resistance of lithium silicate glass-ceramics (LSGCs), with and without crystallization firing after manufacturing.

MATERIALS AND METHODS

Fifty-six specimens were tested in a two-body wear simulator and divided into seven groups. Four groups consisted of commercially available LSGC materials, each opposed to steatite antagonists. A fifth group included an LSGC material tested additionally in its fired state. A sixth group involved another LSGC material opposed to zirconia antagonists. A seventh group comprised zirconia specimens, opposed to steatite antagonists. All specimens underwent a two-body wear test with 250,000 cycles, a 5 kg load, and 1 mm lateral movement, while immersed in either neutral (pH 7) or acidic (pH 3) buffer solutions. Laser scanning microscopy, optical profilometry, and scanning electron microscopy were used to quantify and/or investigate the wear. Data were analyzed using one-way ANOVA.

RESULTS

LSGC materials exhibited significantly higher wear at pH 7 compared to pH 3 (p < 0.001). The greatest volume loss was observed in an unfired LSGC material (0.138 ± 0.039 mm³ at pH 3 vs. 0.495 ± 0.092 mm³ at pH 7). Steatite antagonists also suffered significantly greater wear at pH 7, with the highest antagonist wear recorded at 1.718 ± 0.068 mm³ . The wear mechanism caused by steatite antagonists differed from zirconia antagonists.

SIGNIFICANCE

Environmental conditions play a major role in the wear performance of LSGCs. Fully crystallized LSGC materials show similar susceptibility to environmental changes compared to LSGC materials requiring crystallization firing.

Comparative study of the profile of supragingival dental plaque and tooth decay in patients with lupus erythematosus and rheumatoid arthritis

BACKGROUND AND OBJECTIVES

Systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA) are complex autoimmune diseases that present with a range of systemic and oral manifestations including dental decay and alterations in the oral microbiome profile. The purpose of this study was to compare the fungal and bacterial profile of supragingival dental plaque and dental caries in patients with SLE and RA.

METHODS

The present descriptive-cross-sectional-analytical study was conducted on 91 participants (31 RA, 30 lupus, and 30 control groups). Decayed, Missing, and Filled teeth (DMFT) and The International Caries Detection Assessment System (ICDAS) indices were used to investigate tooth decay. The DAS-28 index was used to assess the severity of RA, and the SLEDAI-2 K index was used to evaluate the severity of lupus. The number of supragingival dental plaque Streptococcus mutans, Lactobacillus spp. and Candida albicans colonies were evaluated using Mitis Salivarius Agar (MSA), deMan-Rogosa-Sharpe agar (MRS) and Sabouraud Dextrose Agar with Chloramphenicol (SC) culture medium, respectively. Data were analyzed using one-way ANOVA, Kruskal -Wallis, k2, Fisher's tests, and Spearman's correlation coefficient.

RESULTS

A statistically significant relationship was observed between the education level (P = 0.030), mean of DMFT, ICDAS, MSA and SC indices (P < 0.001) with the type of disease. The control and RA group showed significantly higher MRS index than the lupus group (P < 0.001). There was significant and positive correlation between the severity of the disease in lupus patients and SC (Candida albicans) (P < 0.001, R = 0.698) and MRS (P = 0/020, R = 0.408) indices.

CONCLUSION

Dental decay and the fungal and bacterial flora of supragingival dental plaque patients are higher than in the healthy group. It is recommended that these patients pay more attention to their oral hygiene and undergo periodic oral examinations.