Do 3D-printed and milled tooth-supported complete monolithic zirconia crowns differ in accuracy and fit? A systematic review and meta-analysis of in vitro studies

STATEMENT OF PROBLEM

Additive (3-dimensional printing) and subtractive (milling) methods are digital approaches to fabricating zirconia restorations. Comparisons of their resultant fabrication accuracy and restoration fit are lacking.

PURPOSE

The purpose of this systematic review and meta-analysis was to evaluate the accuracy and fit of monolithic zirconia crowns fabricated by 3-dimensional printing and milling.

MATERIAL AND METHODS

The PubMed (Medline), Scopus, Embase, Web of Science, Cochrane Library, and Google Scholar databases were searched up to August 2023. Eligible records were included, and the standardized mean difference (SMD) analyzed 4 outcomes: marginal fit, intaglio fit, trueness, and precision. Publication bias was analyzed with Trim-and-fill, the Egger regression test, and Begg funnel plot. Methodological quality was rated using the QUIN tool.

RESULTS

A total of 15 publications were found eligible out of the initial 6539 records. The 3-dimensional printing group demonstrated a lower marginal fit (SMD=1.46, 95% CI=[0.67, 2.26], P<.001; I2=83%, P<.001) and trueness (SMD=0.69, 95% CI=[0.20, 1.18], P=.006; I2=88%, P<.001) and a significantly higher precision (SMD=-2.19, 95% CI=[-2.90, -1.48], P<.001; I2=56%, P=.045). The intaglio fit did not differ significantly across the study groups (SMD=0.77, 95% CI=[-0.22, 1.77], P=.127; I2=87%, P<.001).

CONCLUSIONS

Given the high degree of heterogeneity, it can be cautiously concluded that while 3-dimensional printing led to greater precision, the outcomes of the 2 accuracy and adaptation parameters most crucial to the longevity of the restorations-trueness and marginal fit-showed the superiority of the milling technique.

Dental biomaterials redefined: molecular docking and dynamics-driven dental resin composite optimization

BACKGROUND

Dental resin-based composites are widely recognized for their aesthetic appeal and adhesive properties, which make them integral to modern restorative dentistry. Despite their advantages, adhesion and biomechanical performance challenges persist, necessitating innovative strategies for improvement. This study addressed the challenges associated with adhesion and biomechanical properties in dental resin-based composites by employing molecular docking and dynamics simulation.

METHODS

Molecular docking assesses the binding energies and provides valuable insights into the interactions between monomers, fillers, and coupling agents. This investigation prioritizes SiO2 and TRIS, considering their consistent influence. Molecular dynamics simulations, executed with the Forcite module and COMPASS II force field, extend the analysis to the mechanical properties of dental composite complexes. The simulations encompassed energy minimization, controlled NVT and NPT ensemble simulations, and equilibration stages. Notably, the molecular dynamics simulations spanned a duration of 50 ns.

RESULTS

SiO2 and TRIS consistently emerged as influential components, showcasing their versatility in promoting solid interactions. A correlation matrix underscores the significant roles of van der Waals and desolvation energies in determining the overall binding energy. Molecular dynamics simulations provide in-depth insights into the mechanical properties of dental composite complexes. HEMA-SiO2-TRIS excelled in stiffness, BisGMA-SiO2-TRIS prevailed in terms of flexural strength, and EBPADMA-SiO2-TRIS offered a balanced combination of mechanical properties.

CONCLUSION

These findings provide valuable insights into optimizing dental composites tailored to diverse clinical requirements. While EBPADMA-SiO2-TRIS demonstrates distinct strengths, this study emphasizes the need for further research. Future investigations should validate the computational findings experimentally and assess the material's response to dynamic environmental factors.

Graph neural networks-based prediction of drug gene association of P2X receptors in periodontal pain

The P2X7 receptor, a member of the P2X receptor family, plays a crucial role in various physiological processes, particularly pain perception. Its expression across immune, neuronal, and glial cells facilitates the release of pro-inflammatory molecules, thereby influencing pain development and maintenance, as evidenced by its association with pulpitis in rats. Notably, P2X receptors such as P2X3 and P2X7 are pivotal in dental pain pathways, making them promising targets for novel analgesic interventions. Leveraging graph neural networks (GNNs) presents an innovative approach to model graph data, aiding in the identification of drug targets and prediction of their efficacy, complementing advancements in genomics and proteomics for therapeutic development. In this study, 921 drug-gene interactions involving P2X receptors were accessed through https://www.probes-drugs.org/. These interactions underwent meticulous annotation, preprocessing, and subsequent utilization to train and assess GNNs. Furthermore, leveraging Cytoscape, the CytoHubba plugin, and other bioinformatics tools, gene expression networks were constructed to pinpoint hub genes within these interactions. Through analysis, SLC6A3, SLC6A2, FGF1, GRK2, and PLA2G2A were identified as central hub genes within the context of P2X receptor-mediated drug-gene interactions. Despite achieving a 65 percent accuracy rate, the GNN model demonstrated suboptimal predictive power for gene-drug interactions associated with oral pain. Hence, further refinements and enhancements are imperative to unlock its full potential in elucidating and targeting pathways underlying oral pain mechanisms.

The internal and marginal adaptation of lithium disilicate endocrowns fabricated using intra and extraoral scanners: An in-vitro study

OBJECTIVES

The impression technique highly influences the adaptation of ceramic restorations. Not enough information is available to compare the marginal (MF) and internal fit (IF) of endocrowns fabricated with various digitization techniques. Therefore, this in-vitro study aimed to compare the MF and IF of lithium disilicate (LDS) endocrowns fabricated through direct and indirect digital scanning methods.

MATERIALS AND METHODS

One extracted maxillary molar was used to fabricate endocrowns. The digitization of the model was performed with (G1) direct scanning (n = 10) utilizing an intraoral scanner (IOS), (G2) indirectly scanning the conventional impression taken from the model using the same IOS (n = 10), (G3) indirectly digitalizing the obtained impression using an extraoral scanner (EOS) (n = 10), and (G4) scanning the poured cast using the same EOS (n = 10). The MF and IF of the endocrowns were measured using the replica method and a digital stereomicroscope. The Kruskal-Wallis test was used to analyze data.

RESULTS

The studied groups differed significantly (p<0.001). G2 (130.31±7.87 μm) and G3 (48.43±19.14 μm) showed the largest and smallest mean vertical marginal gap, respectively. G2 and G3 led to the highest and lowest internal gaps in all regions, respectively. With significant differences among the internal regions (p<0.001), the pulpal area demonstrated the most considerable misfit in all groups.

CONCLUSIONS

Scanning the impression using an extraoral scanner showed smaller marginal and internal gaps.

Evaluation of the effect of chemical disinfection and ultraviolet disinfection on the dimensional stability of polyether impression material: an in-vitro study

BACKGROUND

Various methods, chemical and physical, disinfect dental impressions. Common chemicals include 1% Sodium Hypochlorite and 2% glutaraldehyde, while UV radiation is a prevalent physical method. Few studies compare their effects on dimensional stability in polyether impressions. This study aims to assess such stability using different disinfection methods. Therefore, this study was planned to evaluate the dimensional stability of polyether impression material using different disinfection methods.

METHODS

This in vitro study compared the effects of chemical disinfectants (1% Sodium Hypochlorite and 2% glutaraldehyde) and UV irradiation on the dimensional stability of polyether impression material. Groups A, B, C, and D, each with ten samples (N = 10), were studied. Group A was untreated (control). Group B was treated with 2% glutaraldehyde for 20 min, Group C with 1% Sodium Hypochlorite for 20 min, and Group D with UV rays for 20 min. A pilot milling machine drill was used to make four parallel holes labeled A, B, C, and D in the anterior and premolar regions from right to left. After sequential drilling, four implant analogs were positioned using a surveyor for accuracy. Ten open-tray polyether impressions were made and treated as described in the groups, followed by pouring the corresponding casts. Distortion values for each disinfection method were measured using a coordinate measuring machine capable of recording on the X- and Y-axes.

RESULTS

A comprehensive analysis was conducted using the one-way ANOVA test for distinct groups labeled A, B, C, and D, revealing significant differences in the mean distances for X1, X2, X4, X5, and X6 among the groups, with p-values ranging from 0.001 to 0.000. However, no significant differences were observed in X3. Notably, mean distances for the Y variables exhibited substantial differences among the groups, emphasizing parameter variations, with p-values ranging from 0.000 to 0.033. The results compared the four groups using the one-way ANOVA test, revealing statistically significant distance differences for most X and Y variables, except for X3 and Y4. Similarly, post-hoc Tukey's tests provided specific pairwise comparisons, underlining the distinctions between group C and the others in the mean and deviation distances for various variables on both the X- and Y-axes.

CONCLUSIONS

This study found that disinfection with 1% sodium hypochlorite or UV rays for 20 min maintained dimensional stability in polyether impressions.

Dental implant considerations in patients with systemic diseases: An updated comprehensive review

BACKGROUND

Various medical conditions and the drugs used to treat them have been shown to impede or complicate dental implant surgery. It is crucial to carefully monitor the medical status and potential post-operative complications of patients with systemic diseases, particularly elderly patients, to minimize the risk of health complications that may arise.

AIM

The purpose of this study was to review the existing evidence on the viability of dental implants in patients with systemic diseases and to provide practical recommendations to achieve the best possible results in the corresponding patient population.

METHODS

The information for our study was compiled using data from PubMed, Scopus, Web of Science and Google Scholar databases and searched separately for each systemic disease included in our work until October 2023. An additional manual search was also performed to increase the search sensitivity. Only English-language publications were included and assessed according to titles, abstracts and full texts.

RESULTS

In total, 6784 studies were found. After checking for duplicates and full-text availability, screening for the inclusion criteria and manually searching reference lists, 570 articles remained to be considered in this study.

CONCLUSION

In treating patients with systemic conditions, the cost-benefit analysis should consider the patient's quality of life and expected lifespan. The success of dental implants depends heavily on ensuring appropriate maintenance therapy, ideal oral hygiene standards, no smoking and avoiding other risk factors. Indications and contraindications for dental implants in cases of systemic diseases are yet to be more understood; broader and hardcore research needs to be done for a guideline foundation.

Smile aesthetics in Pakistani population: dentist preferences and perceptions of anterior teeth proportion and harmony

BACKGROUND

This study aimed to evaluate dentist perceptions of attractive smiles in the Pakistani population, considering different dental proportions.

METHODS

Maxillary casts and digital images were used to create symmetrical representations of anterior teeth. dentists' preferences for good and bad teeth proportions, width/height ratios, and various dental proportions (golden, recurring esthetic dental (RED), golden percentage, Preston, and local/observed) were assessed using one sample and paired t-test. The Chi-square test was used to determine the gender disparities and factors affecting smile attractiveness. A p-value of ≤ 0.05 was taken as significant.

RESULTS

The RED proportion emerged as the preferred choice for normal-sized teeth, with specialists and general dentists favoring it over the golden proportion. For tall teeth, the golden proportion was predominantly preferred. The golden percentage received limited preference for aesthetic smile construction.

CONCLUSIONS

The smiles created using the principles of RED proportion were opted as the most attractive by local dentists. Factors such as tooth arrangement, color, and midline were highlighted as essential considerations in aesthetic smile construction.

Finite element analysis of stress distribution on residual root structure in socket shield procedure following immediate dental implant placement: an in vitro study

BACKGROUND

The success of implants in the socket shield technique relies on stress experienced by root fragments within the socket. Although there is no consensus on optimal root fragment thickness, varying thicknesses and dynamic implant placement induce stress in various directions and degrees. This study aimed to assess biomechanical response and stress distribution across different root fragment thicknesses in the socket shield procedure.

METHODS

This in vitro study was conducted to assess and compare the stress distribution on residual root structures of varying thicknesses positioned within the labial aspect of the maxillary incisor socket during immediate implant placement of standard dimensions. The procedure involved applying an insertional torque of 40 Ncm, and the analysis was conducted using finite element analysis software.

RESULTS

Utilizing the Numerical Technique with Abaqus software for explicit dynamics, von Mises stress and principal strain were analyzed on the root structure and bone under nonlinear contact conditions during implant torque application. For Model A, a loading torque of 40 Ncm was applied vertically on the implant, along with a horizontal force of 20 N on the root structure and bone. Results indicated maximum stress of 12.68 MPa on the root structure with a thickness of 0.5 mm and 5.61 MPa on the bone, with principal strains of 6.82E-03 and 4.10E-03, respectively. In Model B, with a root structure thickness of 1.0 mm, the maximum stress increased to 19.70 MPa, while the bone stress rose to 9.51 MPa, with principal strains of 1.03E-02 and 6.09E-03. Model C, with a root structure thickness of 1.5 mm, exhibited a maximum stress of 21.58 MPa on the root and 10.12 MPa on the bone, with principal strains of 1.16E-02 and 6.10E-03. Lastly, in Model D, with a root structure thickness of 2.0 mm, the maximum stress on the root structure and bone escalated to 28.74 MPa and 11.38 MPa, respectively, with principal strains of 1.55E-02 and 8.31E-03.

CONCLUSIONS

As the thickness of the shield increases (ranging from 0.5 to 2 mm) in socket shield procedures with immediate implant placement, both stress on the root fragment and bone and principal micro-strain escalate. However, employing a shield thickness within the range of 0.5 to 2 mm does not lead to any adverse stress generation on the residual root fragment. However, for enhanced safety, it is recommended to restrict the maximum diameter and extension of the root fragment to 1.5 mm when considering implant sizes and socket diameter for the socket shield technique.

The effectiveness of botulinum toxin for temporomandibular disorders: A systematic review and meta-analysis

OBJECTIVE

The current body of research on utilizing botulinum toxin (BTX) to manage temporomandibular disorders (TMDs) has not yet yielded definitive conclusions. The primary objective of this study was to determine the effectiveness of BTX in pain reduction for TMDs compared to placebo and other treatments. The secondary outcomes evaluated were adverse events, maximum mouth opening, bruxism events, and maximum occlusal force.

MATERIALS AND METHODS

A literature search was performed on PubMed, Dimension Publication, Scopus, and Google Scholar. The RoB 2 tool was used for quality assessment. The mean differences in pain scores were estimated to measure the effect of BTX on pain reduction. For adverse events, the risk ratio for the incidence of side effects was calculated.

RESULTS

Two hundred and sixty non-duplicate articles were identified; however, only 14 RCTS were included in this review. The total study population included 395 patients. The overall risk of bias showed a low to moderate quality of evidence. Results from 6 studies were reported only narratively; four studies were used for meta-analysis on pain reduction, and five were used for meta-analysis on adverse events. The control used in the meta-analysis was placebo injections. Results of the meta-analysis for pain reduction were statistically insignificant for the BTX group with mean differences at MD = -1.71 (95% CI, -2.87 to -0.5) at one month, -1.53 (95% CI, -2.80 to -0.27) at three months, and -1.33 (95% CI, -2.74 to 0.77) at six months. This showed that BTX treatment was not significantly better than placebo for a reduction in pain scores at 1, 3, and 6 months. Regarding safety, the placebo group showed a relative risk of 1.34 (95%CI, 0.48-6.78) and 1.17 (95%CI, 0.54-3.88) at 1 and 3 months respectively. However, the risks were not statistically significant. There was also no difference in the effectiveness of BTX compared to placebo and other treatments for maximum mouth opening, bruxism events, and maximum occlusal force.

CONCLUSION

BTX was not associated with better outcomes in terms of pain reduction, adverse events, maximum mouth opening, bruxism events, and maximum occlusal force. More high-quality RCTs are needed to better understand this topic.

The role of physiotherapy interventions in the management of temporomandibular joint ankylosis: a systematic review and meta-analysis : Running title: Physiotherapy in TMJ ankylosis

BACKGROUND

The main aim of this systematic review and meta-analysis was to identify peer-reviewed scholarly journal articles reporting the significance of physiotherapy interventions in managing TMJ ankylosis. In addition, this study aimed to critically appraise the existing evidence on the prevalence and clinical presentation, physiotherapy intervention approaches, efficacy of physiotherapy interventions, adverse effects, and safety of physiotherapy interventions in TMJ ankylosis management.

METHODS

An all-inclusive literature search was conducted using the PubMed, Google Scholar, and Scopus electronic databases. The researchers screened the potential articles and assessed for eligibility based on the reported inclusion and exclusion criteria. The quality evaluation tool for observational cohort and cross-sectional studies developed by the National Institutes of Health (NIH) and the Cochrane Collaboration's Risk of Bias Tool were used to assess the quality of the included studies. Researchers also comprehensively analyzed the data, reported the results, and discussed them according to the predominant themes.

RESULTS

The primary electronic database search yielded 409 articles, of which 25 were included in this review. A secondary search was conducted from citations of the included studies, yielding 74 articles, of which six were included in the study. A significantly higher prevalence of bony ankylosis than fibrous ankylosis, with an overall effect size of p < 0.00001. In addition, there were significantly more unilateral than bilateral presentations with an overall effect size of p < 0.00001. Moreover, there were 78 reported complications out of 245 subjects according to five included studies demonstrating a significant effect size with p = 0.001 following the treatment protocols.

CONCLUSION

This study highlighted the prevalence of bony ankylosis in temporomandibular joint ankylosis, emphasizing its impact on patients' well-being. On the other hand, the results show that physiotherapy is essential to optimize postoperative outcomes and minimize adverse events such as re-ankylosis. Practitioners and healthcare professionals must monitor postoperative recovery and ensure strict adherence to physiotherapy protocols for optimal outcomes.

Analysis of shade-matching ability in dental students: a comparative study under clinical and correcting light conditions

BACKGROUND

Selecting the ideal tooth shade is essential to the success of aesthetic dental restorations. Students' cognitive abilities are involved in the multifaceted and intricate process of shade matching. Hence, the present study aimed to assess and compare the shade-matching ability of undergraduate dental students in various years of dental education under clinical and correcting light.

METHODS

This comparative cross-sectional study was instigated amongst male 4th, 5th, and 6th-year students of the dental complex of King Faisal University, Kingdom of Saudi Arabia. A total of 72 male dental students assessed the shade under clinical (fluorescent light) and correcting light (handheld Dental Base Light) by using VITA Classical shade guides. Statistical analysis was done using SPSS version 23 (Armonk, NY, USA). The Chi-square test was used to evaluate the association between correct and incorrect shade matching under correcting and clinical light.

RESULTS

Out of 72 male students, 22(30.6%) were from the 4th year, 26(36.1%) were from the 5th year, and 24(33.3%) were from the 6th year, with a mean age of 22.92 ± 1.01 years. The majority of the 6th-year students selected shade of anterior tooth # 11 correctly under clinical and correcting light, and 3(12.5%) students selected incorrectly under clinical and correcting light, with a statistically significant association among them (p = 0.004). As far as the shade selection of the posterior tooth is concerned, a statistically significant difference was observed under clinical light among all clinical students (p = 0.008).

CONCLUSION

The clinical performance of dental students in shade matching improved with advancing years of dental education. Additionally, the shade matching ability of all groups of dental students was superior under correcting light compared to conditions under clinical light.

The efficacy of iatrosedation and music listening techniques in attenuating dental anxiety in patients undergoing dental crown preparation: A randomized clinical trial

Dental anxiety is a common problem encountered in dental clinics that affects both patients and dentists. Adequate management of dental anxiety is critical for optimal treatment outcomes for the patient. This study aims to assess the efficacy of two anxiety-reduction techniques (iatrosedation and music listening) for dental crown preparation in adult patients. In this clinical trial, 60 patients were randomly assigned to three groups: Group 1, iatrosedation; Group 2, music listening; and Group 3, control. Patients in all three groups underwent dental crown preparation. To measure the anxiety levels of the patients, heart rate was calculated using a pulse oximeter, and verbal rating scale scores were assessed. One-way analysis of variance, post hoc analysis, and Spearman's correlation were used to compare the mean values of the three groups. Significant differences were observed in the heart rate and verbal rating scale scores among individuals in the study groups. A more substantial reduction in anxiety levels was found in patients exposed to iatrosedation (Group 1), which was followed by music listening (Group 2). Recorded heart rate and verbal rating scores were the highest in the control group patients. The iatrosedation technique significantly reduced dental anxiety for patients undergoing dental crown treatment; however, music listening was less effective than iatrosedation. Educating patients regarding the dental care they are about to receive is vital for reducing their anxiety.

Oral findings and comprehensive dental management of Moebius syndrome: a systematic review

BACKGROUND

Moebius syndrome (MS) is a rare, non-progressive, neuromuscular, congenic disease involving the oral maxillofacial region. The present study aimed to describe the oral and extraoral findings in MS patients and their comprehensive dental management.

METHODS

A digital search was carried out in PubMed/MEDLINE, Scopus, Web of Science, and Google Scholar, restricted to articles in English from Jan 01, 2000, to Apr 02, 2023, following PRISMA guidelines. The methodological quality of the studies was evaluated following the JBI guidelines. Qualitative analysis was carried out on the overall result, extraoral and intraoral manifestations, considering dental management as appropriate.

RESULTS

Twenty-three studies were included, and a total of 124 cases of patients with MS were analyzed. The 82% of patients with MS were younger than 15 years of age. The most frequent extraoral manifestations were blinking and visual problems (78,22%), malformations of the upper and lower limbs (58,22%), bilateral facial paralysis (12,90%), lack of facial expression (12.09%), and unilateral facial paralysis (6,45%). On the other hand, the most frequent oral manifestations were tongue deformities (78,22%), micrognathia (37,90%), labial incompetence (36,29%), cleft palate (22,87%), gothic palate (16,12%), microstomia (15,32%), anterior open bite (15,32%), dental caries (8,87%), and periodontal disease (8,06%). The majority of MS patients were treated by pediatric dentistry (60,86%), using a surgical approach (56,52%), and orthodontic and orthopedic maxillary (43,47%) followed by restorative (39,13%), and periodontal treatments (21,73%).

CONCLUSIONS

This systematic review demonstrates that patients with MS present a wide variety of oral and extraoral manifestations, for which dental treatments are planned and tailored to each patient in accordance with oral manifestations. These treatments encompass problem resolution and oral health maintenance, incorporating recent techniques in managing and treating patients with MS.

Conventional maxillary denture versus maxillary implant-supported overdenture opposing mandibular implant-supported overdenture: Patient's satisfaction

OBJECTIVES

This study sought to determine the impact of age, gender, and use of maxillary implant-supported overdenture (UISOD) versus conventional denture (CMD) opposing mandibular implant-supported overdenture (LISOD) and the number of years the patient has used their prosthesis on the ratings of satisfaction. This study aimed to assess the long-term influence of different factors on patients' satisfaction with LISODs needing a maxillary prosthesis, helping dentists choose a treatment pathway that leads to a higher satisfaction rate.

MATERIAL AND METHODS

This cross-sectional study included 84 participants. They were treated with LISOD opposing either CMD or UISOD from 2015 to 2020. They were all eligible to participate in the study. An oral health impact profile (OHIP-14) questionnaire was given to each patient and filled out by them. OHIP-14 scores were gathered and went under statistical analysis with PASS-11 software to determine the relationship between patients' satisfaction with the scores.

RESULTS

Age and gender had no significant influence on how satisfied patients were. Patients with maxillary overdentures showed more satisfaction than the CMD group (p < .05). Moreover, patients' satisfaction decreased with increasing years of prostheses usage (p < .05).

CONCLUSIONS

This study demonstrated that satisfaction is related to the type of maxillary prosthesis (conventional or implant-supported) used opposing LISODs and the number of years the patient had used the prostheses.

Exploring the Use of Animal Models in Craniofacial Regenerative Medicine: A Narrative Review

The craniofacial region contains skin, bones, cartilage, the temporomandibular joint (TMJ), teeth, periodontal tissues, mucosa, salivary glands, muscles, nerves, and blood vessels. Applying tissue engineering therapeutically helps replace lost tissues after trauma or cancer. Despite recent advances, it remains essential to standardize and validate the most appropriate animal models to effectively translate preclinical data to clinical situations. Therefore, this review focused on applying various animal models in craniofacial tissue engineering and regeneration. This research was based on PubMed, Scopus, and Google Scholar data available until January 2023. This study included only English-language publications describing animal models' application in craniofacial tissue engineering (in vivo and review studies). Study selection was based on evaluating titles, abstracts, and full texts. The total number of initial studies was 6454. Following the screening process, 295 articles remained on the final list. Numerous in vivo studies have shown that small and large animal models can benefit clinical conditions by assessing the efficacy and safety of new therapeutic interventions, devices, and biomaterials in animals with similar diseases/defects to humans. Different species' anatomical, physiologic, and biological features must be considered in developing innovative, reproducible, and discriminative experimental models to select an appropriate animal model for a specific tissue defect. As a result, understanding the parallels between human and veterinary medicine can benefit both fields.

The flexural strength of 3D-printed provisional restorations fabricated with different resins: a systematic review and meta-analysis

BACKGROUND

Three-dimensional (3D) printing technology has revolutionized dentistry, particularly in fabricating provisional restorations. This systematic review and meta-analysis aimed to thoroughly evaluate the flexural strength of provisional restorations produced using 3D printing while considering the impact of different resin materials.

METHODS

A systematic search was conducted across major databases (ScienceDirect, PubMed, Web of Sciences, Google Scholar, and Scopus) to identify relevant studies published to date. The inclusion criteria included studies evaluating the flexural strength of 3D-printed provisional restorations using different resins. Data extraction and quality assessment were performed using the CONSORT scale, and a meta-analysis was conducted using RevMan 5.4 to pool results.

RESULTS

Of the 1914 initially identified research articles, only 13, published between January 2016 and November 2023, were included after screening. Notably, Digital Light Processing (DLP) has emerged as the predominant 3D printing technique, while stereolithography (SLA), Fused Deposition Modeling (FDM), and mono-liquid crystal displays (LCD) have also been recognized. Various printed resins have been utilized in different techniques, including acrylic, composite resins, and methacrylate oligomer-based materials. Regarding flexural strength, polymerization played a pivotal role for resins used in 3D or conventional/milled resins, revealing significant variations in the study. For instance, SLA-3D and DLP Acrylate photopolymers displayed distinct strengths, along with DLP bisacrylic, milled PMMA, and conventional PMMA. The subsequent meta-analysis indicated a significant difference in flexure strength, with a pooled Mean Difference (MD) of - 1.25 (95% CI - 16.98 - 14.47; P < 0.00001) and a high I2 value of 99%, highlighting substantial heterogeneity among the studies.

CONCLUSIONS

This study provides a comprehensive overview of the flexural strength of 3D-printed provisional restorations fabricated using different resins. However, further research is recommended to explore additional factors influencing flexural strength and refine the recommendations for enhancing the performance of 3D-printed provisional restorations in clinical applications.

Properties of a novel composite elastomeric polymer vinyl polyether siloxane in comparison to its parent materials: a systemic review and meta-analysis

BACKGROUND

The effectiveness of newly developed elastomeric polymer hybrid siloxane (PVES), which combines the properties of polyethylene (PE) and polyvinyl siloxane (PVS) elastomers, has been a subject of interest in recent studies. This study aimed to assess the physical properties of hybrid PVES materials by analyzing existing data from recent studies on this topic.

METHODS

A systematic literature search was conducted to retrieve peer-reviewed articles published up to February 5, 2023. The population, intervention, comparison, and pertinent outcomes were specified under the PICO framework. The primary data analysis was performed in Microsoft Excel, while statistical analysis used Meta-Essentials.

RESULTS

Of the 1152 articles assessed, 14 met the inclusion criteria. The meta-analysis of the selected studies indicated that polyether (PE) and polyvinyl siloxane (PVS) were highly correlated (two-tailed p-values of 0.000 and 0.001, respectively) with the improved tensile strength of vinyl polyether siloxane (PVES) with a significantly positive effect size. Similarly, the hydrophilic characteristics of PVES were significantly improved compared to those of PE and PVS. PE was a significant contributor to the hydrophilic characteristics of PVES, with a two-tailed p-value of 0.000. The effect size was highly positive for hydrophilicity but showed high heterogeneity. It was also observed that the dimensional accuracy of PVES was comparable to those of PE and PVS, with no statistically significant differences among the three materials.

CONCLUSIONS

PVES showed promising features, with improved tensile strength and hydrophilic characteristics compared to those of PE and PVS.

Comparative analysis of different types of occlusal splints for the management of sleep bruxism: a systematic review

BACKGROUND

Sleep bruxism is a prevalent condition in dentistry practice, characterized by involuntary grinding or clenching of the teeth during sleep. Several therapies, including occlusal splints, have been used to manage sleep bruxism and temporomandibular disorders, including occlusal splints. This study aimed to compare the effectiveness of different occlusal splints in managing sleep bruxism.

METHODS

The PICO framework encompasses the characterization of the population, intervention, comparison, and pertinent outcomes. A comprehensive and systematic literature review was conducted on PubMed, Scopus, and Google Scholar to identify grey literature. The search specifically targeted scientific studies published before September 20, 2023. The Cochrane Collaboration Risk of Bias Tool assessed the accuracy of the included Randomized Control Trials (RCTs). The modified Newcastle-Ottawa Scale assessed non-randomized studies. Data were systematically extracted, synthesized, and reported thematically.

RESULTS

Out of the total of 808 articles that were evaluated, only 15 articles were found to meet the specified inclusion criteria. Adjustable splints, such as full-occlusion biofeedback splints, were more effective in reducing sleep bruxism episodes, improving patient-reported symptoms, and enhancing overall well-being. The impact of different occlusal sprints on electromyographic activity varies, and potential adverse effects should be considered individually.

CONCLUSIONS

This review provides valuable insights into the effectiveness of occlusal splints in managing sleep bruxism. The results of this study indicate that occlusal splint therapy is a viable treatment approach for sleep bruxism.

Full-ceramic resin-bonded fixed dental prostheses: A systematic review

Despite the development of implant-supported prostheses, there are still patients for whom conservative treatments such as resin-bonded fixed dental prostheses (RBFDPs) are more appropriate. This study's objective was to analyze the available research on full-ceramic RBFDPs. In this study, Web of Science, MEDLINE/PubMed, Scopus, Embase, Cochrane Library, and Google Scholar databases were searched for articles published in English between 2010 and 2020. A total of 14 studies were reviewed based on the eligibility criteria. The results showed that using a cantilever design with one abutment had an advantage over two abutments. Additionally, it was proposed that preparations designed with retentive aids, such as a proximal box, groove, and pinhole, could improve RBFDP survival rates. IPS e.max ZirCAD, In-Ceram alumina, and zirconia CAD/CAM were the most commonly used framework materials. Most studies used air abrasion, salinization, or hydrofluoric acid for surface treatment. Adhesive resin cements were the most frequently used type of cement. The survival rate of In-Ceram ceramics (85.3%-94.8%) was lower than that of In-Ceram zirconia and IPS e.max ZirCAD. Debonding, followed by framework fracture, was the leading cause of failure. Following 3-10 years follow-up, the survival percentage of all-ceramic RBFDPs ranged from 76% to 100%. Although RBFDPs have demonstrated satisfactory success as a conservative treatment, long-term follow-ups and higher sample sizes in clinical research are required to gain more reliable outcomes on the clinical success rate of various RBFDP designs.

Attachment and proliferation of human gingival fibroblasts seeded on barrier membranes using Wharton's jelly-derived stem cells conditioned medium: An in vitro study

The effect of Wharton's jelly mesenchymal stem cells conditioned medium (WJMSCs-CM) and zinc oxide nanoparticles (ZnO-NPs) on cultured human gingival fibroblasts on various barrier membranes was investigated in this study. In this study, human gingival fibroblasts were prepared and cultured on three membranes: collagen membrane, acellular dermal matrix (ADM) with ZnO-NPs, and ADM without ZnO-NPs. WJMSCs-CM was given to the testing groups, while control groups received the same membranes without WJMSCs-CM. Following 48 and 72 h, 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) tests were performed to assess cell survival. Cell proliferation on the membranes was also evaluated using 4',6-diamidino-2-phenylindole (DAPI) staining after 48 and 72 h. Field emission scanning electron microscopy was used to determine membrane surface structure and cell adhesion. Nanoparticles were also subjected to an energy-dispersive x-ray analysis to identify their chemical structure. Two-way analysis of variance was used to conduct the statistical analysis. The p-value ≤.05 was considered significant. When ADM-ZnO-NPs were combined with CM, fibroblast viability, and adhesion significantly differed from ADM-ZnO-NPs alone. DAPI results confirmed cell proliferation in all six groups on both experiment days. The abundance and concentrated distribution of cells during cell proliferation were found in CM-containing membranes, specifically the ADM-ZnO-NPs membrane, demonstrating the improved biocompatibility of the ADM-ZnO-NPs membrane for cell proliferation. The other groups did not significantly differ from one another. WJMSCs-CM positively affected the viability and proliferation of gingival fibroblasts, but only marginally. Under certain conditions, ZnO-NPs below a specific concentration increased the biocompatibility of the membranes.

The Effect of Various Lasers on the Bond Strength Between Orthodontic Brackets and Dental Ceramics: A Systematic Review and Meta-Analysis

Background/objective: This systematic review and meta-analysis aimed to assess how laser conditioning affected brackets bonded to dental ceramics' shear bond strength (SBS). Materials and methods: The study was conducted by searching Pubmed/Medline, Scopus, Embase, Web of Science, the Cochrane Library, and Google Scholar up to September 14, 2022. In addition, the reference lists of the relevant articles were checked manually. Articles that compared SBS of laser-treated feldspathic, lithium disilicate, or zirconia surfaces with other standard techniques for bonding metal or ceramic orthodontic brackets were considered. Using a random-effects model, data pooling was carried out as the weighted mean difference (WMD). Results: This study initially contained 1717 reports, and following review, 32 articles were deemed suitable for our meta-analysis. The pooling results showed that the treatments with lasers such as "Er:YAG" [WMD = -1.12 MPa; 95% confidence interval (CI): -1.93 to -0.31], "Er:YAG + Silane" (WMD = -3.08 MPa; 95% CI: -4.77 to -1.40), and "Nd: YAG + Silane" (WMD = -2.58 MPa; 95% CI: -3.76 to -1.40) had statistically significant lower adhesion values compared with controls. Contrarily, "Ti:Sapphire femtosecond" demonstrated significantly higher bonding values (WMD = 0.94 MPa; 95% CI: 0.29-1.60). In contrast, other interventions obtained no statistically significant difference in SBS. Conclusions: Most of the laser groups showed results comparable with those of conventional approaches. Although more research is necessary for definitive conclusions, laser treatment may be an effective option for treating the surfaces of ceramic materials.

Implant-supported prosthetic rehabilitation after Ameloblastomas treatment: a systematic review

BACKGROUND

Ameloblastoma (AM), the benign counterpart of ameloblastic carcinoma, is a benign odontogenic tumor of epithelial origin, naturally aggressive, with unlimited growth potential and a high tendency to relapse if not adequately removed. Patients with AM treated surgically can benefit from dental implant therapy, promoting oral rehabilitation and improving their quality of life. The present study aimed to determine the survival rate of dental implants placed after surgical treatment of patients affected by AM. In addition, there were two secondary objectives: 1) To evaluate which dental implant loading protocols are most frequently used and 2) To determine the type of prosthetic restoration most commonly used in these patients.

METHODS

The Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) guidelines were followed during the study. Searches were performed in three databases (PubMed/MEDLINE, Scopus, and Google Scholar) until November 2023. Additionally, the electronic search was enriched by an iterative hand search of journals related to oral pathology and medicine, maxillofacial surgery, and oral prosthodontics and implantology. Only reports and case series in English from January 2003 to date were included. The Joanna Briggs Institute tool (JBI-Case Reports/Case Series) was used for the study quality assessment.

RESULTS

The total number of patients and implants studied were 64 and 271, respectively, all with surgically treated AM. The patient's ages ranged from 8 to 79 years, with a mean (SD) age of 37.3 ± 16.4. Fifty-three percent were male and 47% were female. The range of follow-up duration was 1 to 22 years. An implant survival/success rate of 98.1% was reported. In addition, most of them were conventionally loaded (38.3%). Hybrid implant-supported fixed dentures were the most commonly used by prosthodontists (53%).

CONCLUSIONS

Oral rehabilitation with dental implants inserted in free flaps for orofacial reconstruction in surgically treated patients with AM can be considered a safe and successful treatment modality.

Application of density functional theory for evaluating the mechanical properties and structural stability of dental implant materials

BACKGROUND

Titanium is a commonly used material for dental implants owing to its excellent biocompatibility, strength-to-weight ratio, corrosion resistance, lightweight nature, hypoallergenic properties, and ability to promote tissue adhesion. However, alternative materials, such as titanium alloys (Ti-Al-2 V) and zirconia, are available for dental implant applications. This study discusses the application of Density Functional Theory (DFT) in evaluating dental implant materials' mechanical properties and structural stability, with a specific focus on titanium (Ti) metal. It also discusses the electronic band structures, dynamic stability, and surface properties. Furthermore, it presents the mechanical properties of Ti metal, Ti-Al-2 V alloy, and zirconia, including the stiffness matrices, average properties, and elastic moduli. This research comprehensively studies Ti metal's mechanical properties, structural stability, and surface properties for dental implants.

METHODS

We used computational techniques, such as the CASTEP code based on DFT, GGA within the PBE scheme for evaluating electronic exchange-correlation energy, and the BFGS minimization scheme for geometry optimization. The results provide insights into the structural properties of Ti, Ti-Al-2 V, and zirconia, including their crystal structures, space groups, and atomic positions. Elastic properties, Fermi surface analysis, and phonon studies were conducted to evaluate the tensile strength, yield strength, ductility, elastic modulus, Poisson's ratio, hardness, fatigue resistance, and corrosion resistance.

RESULTS

The findings were compared with those of Ti-Al-2 V and zirconia to assess the advantages and limitations of each material for dental implant applications. This study demonstrates the application of DFT in evaluating dental implant materials, focusing on titanium, and provides valuable insights into their mechanical properties, structural stability, and surface characteristics.

CONCLUSIONS

The findings of this study contribute to the understanding of dental implant material behavior and aid in the design of improved materials with long-term biocompatibility and stability in the oral environment.

Effect of Mangifera Indica (Mango) on Dental Caries: A Systematic Review

The present study aimed to evaluate the effect of Mangifera indica (mango) on dental caries. The entire plant, including the leaves, fruit, roots, and flowers, has various therapeutic characteristics used for centuries to cure various illnesses. This systematic review aimed to identify an inexpensive, simple, and effective method of preventing and controlling dental caries. The search was performed among the studies written in English, the database of abstracts concentrating on the effects of Mangifera indica (Mango) on dental caries detected in Pubmed, Scopus, Google Scholar, and Central. In total, we find 37 articles. The relevant English language articles published up to August 2022 were collected, screened, and reviewed. Search words contained "Mangifera indica" and "dental caries" or "Streptococcus mutans" or "tooth demineralization." For our systematic review analysis, we included 3 randomized controlled trial studies studying a total of 130 people, of whom 110 were children aged 8 to 14 and 20 were adults aged 20 to 25. These experiments all employed mouthwash containing an extract from Mangifera indica. In conclusion, it has been proven in 2 separate studies that saliva's PH will increase significantly. In addition, a reduction of S. mutants has been observed in another research. Overall, it was concluded that mango extract mouthwash is highly effective in decreasing the bacteria that can cause dental caries. however, we firmly believe that conduction of more detailed in vivo studies regarding Mangifera indica implications in dental caries treatment is essentially needed for further confirmation.

Comparative evaluation of open tray impression technique: investigating the precision of four splinting materials in multiple implants

BACKGROUND

This study aimed to determine the relative positioning accuracy of multiple implants utilizing four distinct types of splinting materials.

METHODS

The purpose of this in-vitro study was to compare the precision of four splinting materials in an open tray impression technique in multiple implant situations. Based on the material used for splinting, four groups were made (n = 40)- Group A: Conventional Method, Group B: Prefabricated Pattern Resin Framework, Group C: Prefabricated Metal Framework, Group D: Light Cured Pattern Resin, these groups were compared with the master model. A heat-cured clear acrylic resin and a master model were constructed. A pilot milling machine drill was used to drill four parallel holes in the anterior and premolar regions, which were later labeled as A, B, C, and D positions from right to left. Then, sequential drilling was carried out, and four 3.75‑mm diameter and 13-mm long ADIN implant analogs with internal hex were placed in the acrylic model using a surveyor for proper orientation. The impression posts were then manually screwed to the implant analogs using an open tray, and they were secured to the implants using 10 mm flat head guide pins with a 15 N.cm torque. 10 Open tray polyether impressions were made, and casts were poured. Each splinting method's distortion values were measured using a coordinate measuring machine capable of recordings in the X-, Y-, and Z-axes. Comparison of mean distances for X1, X2, and X3 was made using the Kruskal-Wallis test, and Pairwise comparison was done using Post Hoc Tukey's Test.

RESULTS

The differences between the groups were significant when assessing the distances X1, X2, and X3 (p < 0.05). The comparison of deviations between the groups revealed a statistically significant difference (p < 0.05) for the deviation distance X3 but not for the deviation distances X1 and X2. For distance Y1, the difference between the groups was statistically significant (p0.05), but it was not significant for distances Y2 and Y3. A statistically significant difference was seen in the comparison between the groups (p < 0.05) for the deviation distances Y1, Y2, and Y3. The results were statistically significant for the distance Z1 comparisons, namely, control vs. Group A (p = 0.012), control vs. Group B (p = 0.049), control vs. Group C (p = 0.048), and control vs. Group D (p = 0.021), and for distance Z3 comparison for control vs. Group A (p = 0.033). The results were statistically insignificant for the distance Z2 comparisons (p > 0.05).

CONCLUSIONS

All splinting materials produced master casts with measurements in close proximity to the reference model. However, prefabricated pattern resin bars splinting showed the highest accuracy among the studied techniques. The most recent splinting techniques using prefabricated metal framework and light-cure pattern resin showed similar accuracy.

Oral Complications Associated with the Piercing of Oral and Perioral Tissues and the Corresponding Degree of Awareness among Public and Professionals: A Systematic Review

This study systematically reviews the literature to evaluate the potential relationships between oral/perioral piercing and consequent oral complications in the corresponding society. The second objective was determining public/professional sectors' awareness of the subject. This research followed PRISMA and Cochrane guidelines for conducting systematic reviews and searching scientific databases, including PubMed, Scopus, Cochrane, and Google Scholar, until April 2023. Cross-sectional, cohort, and case-control studies in English were deemed eligible. The methodological quality of the included studies was assessed using proper quality assessment guidelines. Of the 965 initial articles retrieved, 34 were considered suitable for qualitative synthesis after screening procedures and removing duplicates and irrelevant records. There appears to be an imbalance between the general public's low and dentists' high awareness. This draws attention to the shortage of professional and societal knowledge-sharing and education initiatives. Women were more than twice as likely as men to have oral piercings. Piercing usage had a low incidence among a cohort of students with a mean age of 16. Merely circumstantial evidence has indicated a plausible correlation between oral and perioral piercings and the emergence of secondary bacterial and fungal colonization, particularly periodontopathogenic bacteria and Candida albicans. Furthermore, several adverse consequences have been observed linked to various piercings-such as lip and tongue piercings. These include caries, gingivitis/periodontitis, dental fractures, enamel chipping/cracks, plaque buildup, bone loss, bleeding, inflammation, and swelling. Given the risks involved and the complications that might impair oral health, the prevalence of oral piercings is alarming. As a result, public health authorities need to firmly support initiatives to raise awareness of the risks associated with oral/perioral piercings. For piercers to enhance their expertise in this field, professional training is necessary because there is a shortage of knowledge on the possible adverse effects of piercings.

The role of periodontitis-associated bacteria in Alzheimer's disease: A narrative review

Alzheimer's disease causes memory loss and dementia in older adults through a neurodegenerative mechanism. Despite the pathophysiological clarification of this cognitive disorder, novel molecular and cellular pathways should be identified to determine its exact mechanism. Alzheimer's disease (AD) is pathologically characterized by senile plaques comprising beta-amyloid and neurofibrillary tangles (NFTs) formed by hyperphosphorylated tau as a microtubule-associated protein with a key role in the pathogenesis of AD. Periodontitis through inflammatory pathways is a risk factor for deteriorating cognitive impairment in AD patients. Poor oral hygiene coupled with immunocompromised status in older adults causes periodontal diseases and chronic inflammations through an oral bacterial imbalance. Toxic bacterial products, including bacteria themselves, can reach the central nervous system through the bloodstream and evoke inflammatory responses. The present review was conducted to investigate relationships between AD and periodontitis-involved bacteria as a risk factor.

Could various angulated implant depths affect the positional accuracy of digital impressions? An in vitro study

PURPOSE

The purpose of this in vitro investigation was to assess how implant depth could affect the three-dimensional positional accuracy of digital impressions made from angulated implants.

MATERIALS AND METHODS

Four modified maxillary models were printed and divided into four study groups. In each model, two angulated implant analogs were placed at the sites of the first premolar and first molar at four different depths of 1 (G1), 2 (G2), 3 (G3), and 4 (G4) mm from the models' edentate area. Scan bodies were connected to the analogs, and one operator made 10 full-arch scans for each master model using an intraoral scanner. Afterward, the marginal gingival part of all models was removed, and digital scans were performed for each model using a laboratory scanner to achieve a reference STL file as the control group. One-way ANOVA and Leven's tests were used to measure and compare the 3D distance deviations across research groups after the superimposing test and control scans.

RESULTS

A significant difference between research groups was revealed by trueness and precision analysis (p < 0.001). The trueness and precision results obtained for G1 and G4 were significantly better than those for G2 and G3 (p < 0.05).

CONCLUSION

This study demonstrated that implant depth could affect the digital implant impressions' 3D positional accuracy.

Comparison of marginal and internal adaptation of provisional polymethyl methacrylate restorations fabricated by two three-dimensional printers: An in vitro study

Background

Chairside fabrication of provisional restorations using three-dimensional (3D) printers is rising in digital dentistry. The purpose of this research was to compare the marginal and internal adaptation of provisional polymethyl methacrylate (PMMA) restorations fabricated by two different 3D printers.

Materials and Methods

In this in vitro investigation, an intact maxillary 1st molar acrylic model was first digitalized by a laboratory scanner. It was then prepared for an all-ceramic restoration and scanned again by the same scanner. The final restoration was designed in Exocad according to the scan files with a 50 μm cement gap. PMMA restorations were printed by two 3D printers; Group 1: Asiga (n = 10) and Group 2: Digident (n = 10). The replica technique was used to assess the marginal and internal fit of the restorations, and one-way ANOVA was used to analyze the data. P <0.05 was regarded as statistically significant.

Results

The mean marginal gap of crowns in Group 1 was significantly lower than that of Group 2 (75 vs. 195 μm, P = 0.001). Regarding internal adaptation, no significant difference was found between the axial gap values in both groups (P > 0.05). The mean occluso-axial gap (90 vs. 140 μm, P = 0.026) and the mean occlusal gap (116 vs. 300 μm, P = 0.001) of crowns in Group 1 were significantly smaller compared to the equivalent values in Group 2.

Conclusion

Provisional PMMA crowns fabricated by the Asiga printer showed significantly higher marginal and internal adaptation than those manufactured by Digident at all points except for the axial surface.

The effect of leukocyte- and platelet-rich fibrin on the bone loss and primary stability of implants placed in posterior maxilla: a randomized clinical trial

PURPOSE

In this study, we investigated the effects of leukocyte- and platelet-rich fibrin (L-PRF) on implant stability and alterations in the marginal bone surrounding posterior maxillary implants.

METHODS

This randomized clinical trial was conducted to compare the variable of L-PRF placement around maxillary implants. Resonance frequency analysis (RFA) was used to evaluate the implant stability immediately after surgery and at 1, 2, 4, 6, 8, and 12 weeks after surgery (t0 to t6, respectively). In addition, the amount of marginal bone changes around the implant at t6 was compared with the baseline using periapical radiography.

RESULTS

The RFA outcomes were statistically significant within each group (P < 0.001, Eta2 = 0.322); however, in none of the follow-ups and immediately after the surgery, there was a significant difference between the two groups in terms of the implant stability quotient (ISQ) scores (P > 0.05). At t0, the test and control groups' respective mean levels of marginal bone loss around the implants were 0.4836 mm and 0.7343 mm, significantly different from the corresponding values at t6. On the other hand, marginal bone loss around the implant was not significantly different between the two groups in t0 and t6 (P = 0.532).

CONCLUSIONS

L-PRF did not improve the RFA outcomes of implants three months after implant placement, and changes in the ISQ values over time were the same in both groups. In addition, L-PRF had no superior effect on the marginal bone loss around the implants.

TRIAL REGISTRATION NUMBER

The research was registered in the Iranian Registry of Clinical Trials on 22 December 2020 (No: IRCT20200624047906N1), available at http://www.irct.ir.

Diagnostic efficacy of cone-beam computed tomography for detection of vertical root fractures in endodontically treated teeth: a systematic review

BACKGROUND

Vertical root fractures (VRFs) sometimes occur in endodontically treated teeth. They have a difficult diagnosis and a dismal result. The objective of this review was to evaluate the diagnostic performance of cone-beam computed tomography (CBCT) for detecting VRFs in teeth that had undergone endodontic treatment.

METHODS

Literature was reviewed from Web of Science, PubMed, Cochrane Review, SCOPUS, and Embase databases between 2000 and 2022. The searched keywords included "endodontically treated teeth," "cone-beam computed tomography," "CBCT," "tooth fracture," "vertical root fracture," "VRF," "accuracy," "sensitivity," and "specificity." Only articles in the English language were included. The final analysis included 20 papers that satisfied the eligibility requirements.

RESULTS

The overall mean ± SD values (%) for the diagnostic sensitivity and specificity of CBCT for detection of VRFs in endodontically treated teeth in the presence of root-filling materials without an intracanal post were 71.50 ± 22.19 and 75.64 ± 19.41, respectively. The overall mean (SD) value (%) for the sensitivity of CBCT for the detection of VRFs in the presence of root-filling materials and intracanal posts was 72.76 (18.73), while the mean (SD) specificity was 75.44 (18.26). The accuracy of CBCT (mean ± SD) was 78.47 ± 17.19% and 74.02 ± 10.64%, respectively, for teeth without intracanal posts and those with posts.

CONCLUSIONS

Further clinical research is needed to validate the optimum efficiency of CBCT as a diagnostic technique for detecting VRFs in teeth that have had endodontic treatment, given the low sensitivity, significant heterogeneity of studies, and lack of in-vivo studies on the subject.

Photodynamic Therapy in Oral Cancer: A Narrative Review

Methods: A comprehensive search in PubMed, Scopus, and Google Scholar was performed using relevant keywords to structure this narrative review. Only English articles were included and assessed according to titles, abstracts, and full texts. Background: Photodynamic therapy (PDT) is applied for targeting pre-malignancy and malignancies in the head and neck, skin, lungs, and gastrointestinal tract and has been greatly promising in reducing disfigurement and morbidity. This method includes a light-sensitive medicine known as a photosensitizer and a light source used through a minimally invasive surgical tool. Objective: This study aimed to review the application of PDT in managing head and neck cancers (HNCs) and provide an overview of the most recent advances in PDT and its efficiency in increasing the long-term life quality of patients with HNC. Results: The light source irradiates light at an appropriate wavelength that can be absorbed by the sensitizer and produce cytotoxic free radicals that can kill tumor cells, impair microvasculature in the tumor microenvironment, and stimulate further inflammatory responses of the immune system. Patients with either early lesions or advanced disease conveniently accept to receive PDT in outpatient clinics. Therefore, this simple technique is considered a novel and promising approach that can be used either individually or in association with other methods. However, its application as a management method in oral malignancies has yet to be studied. PDT is also suggested as a promising adjuvant treatment with better functional results. Then, it is possible to conclude that PDT's effectiveness in treating various tumors has been shown to depend on the depth of the lesion location. Its safety is acceptable, but its limited irradiation depth confines its application in the advanced stages of cancer. Conclusions: PDT is critically applicable in the early diagnosed cancers and superficial tumors where many heads and neck lesions settle as an ideal candidate for PDT because of the possibility of accurate evaluation of lesions and providing appropriate irradiation at these sites.

Interactions between systemic diseases and oral microbiota shifts in the aging community: A narrative review

As a gateway to general health and a diverse microbial habitat, the oral cavity is colonized by numerous microorganisms such as bacteria, fungi, viruses, and archaea. Oral microbiota plays an essential role in preserving oral health. Besides, the oral cavity also significantly contributes to systemic health. Physiological aging influences all body systems, including the oral microbial inhabitants. The cited effect can cause diseases by forming dysbiotic communities. Since it has been demonstrated that microbial dysbiosis could disturb the symbiosis state between the host and the resident microorganism, shifting the condition toward a more pathogenic one, this study investigated how the oral microbial shifts in aging could associate with the development or progression of systemic diseases in older adults. The current study focused on the interactions between variations in the oral microbiome and prevalent diseases in older adults, including diabetes mellitus, Sjögren's syndrome, rheumatoid arthritis, pulmonary diseases, cardiovascular diseases, oral candidiasis, Parkinson's disease, Alzheimer's disease, and glaucoma. Underlying diseases can dynamically modify the oral ecology and the composition of its resident oral microbiome. Clinical, experimental, and epidemiological research suggests the associations of systemic disorders with bacteremia and inflammation after oral microbial changes in older adults.

Green Alternatives as Antimicrobial Agents in Mitigating Periodontal Diseases: A Narrative Review

Periodontal diseases and dental caries are the most common infectious oral diseases impacting oral health globally. Oral cavity health is crucial for enhancing life quality since it serves as the entranceway to general health. The oral microbiome and oral infectious diseases are strongly correlated. Gram-negative anaerobic bacteria have been associated with periodontal diseases. Due to the shortcomings of several antimicrobial medications frequently applied in dentistry, the lack of resources in developing countries, the prevalence of oral inflammatory conditions, and the rise in bacterial antibiotic resistance, there is a need for reliable, efficient, and affordable alternative solutions for the prevention and treatment of periodontal diseases. Several accessible chemical agents can alter the oral microbiota, although these substances also have unfavorable symptoms such as vomiting, diarrhea, and tooth discoloration. Natural phytochemicals generated from plants that have historically been used as medicines are categorized as prospective alternatives due to the ongoing quest for substitute products. This review concentrated on phytochemicals or herbal extracts that impact periodontal diseases by decreasing the formation of dental biofilms and plaques, preventing the proliferation of oral pathogens, and inhibiting bacterial adhesion to surfaces. Investigations examining the effectiveness and safety of plant-based medicines have also been presented, including those conducted over the past decade.

Assessing the Surface Modifications of Contaminated Sandblasted and Acid-Etched Implants Through Diode Lasers of Different Wavelengths: An In-Vitro Study

Objective: The present study was conducted to compare the effects of 810 nm, 980 nm, and dual (810: 50%-980: 50%) diode lasers on the surface modifications of implants contaminated by a standard strain of Escherichia coli. Methods: Based on the operation on their surface, the implants were divided into six groups: "Group 1" was the positive control group undergoing no specific procedures. "Groups 2, 3, 4, 5, and 6" were contaminated by a standard strain of E. coli; "Group 2" was also set as the negative control group. "Groups 3, 4, and 5" were irradiated by 810 nm, 980 nm, and dual lasers (810: 50%-980: 50%; 1.5W, 320 μm fiber) for 30 sec, respectively. "Group 6" was treated using standard titanium brushes. All groups were examined to evaluate the surface modifications by the X-ray diffraction analysis, scanning electron microscope, and atomic force microscopy. Results: The values of carbon, oxygen, aluminum, titanium, and vanadium were significantly different in the surface composition of the contaminated implants from the control groups (p = 0.010, 0.033, 0.044, 0.016, and 0.037, respectively). In all target areas, there were significant differences in surface roughness (p < 0.0001); the same was also true about the pairwise comparison of the study groups (p < 0.0001). "Group 5" demonstrated lower morphological surface changes and roughness degrees. Conclusions: Overall, laser irradiation could alter the surfaces of the contaminated implants. Titanium brushes and 810/980 nm lasers resulted in similar morphological alterations. Dual lasers enjoyed the least degree of morphological alterations and surface roughness.

Oral rehabilitation with dental implants in patients with systemic sclerosis: A systematic review

Objective

To assess the influence of systemic sclerosis (SSc) on the survival rate of dental implants in SSc patients receiving implant‐supported treatments.

Methods

The Preferred Reporting Items for Systematic Reviews and Meta‐analysis (PRISMA) Statement and the Cochrane Collaboration's guiding principles were followed during the study's execution. The data from three databases, PubMed, Google Scholar, and Scopus, available until January 2023, were used to compile the material for our research. Only English‐language publications were submitted for this research and evaluated based on their titles, abstracts, and full texts. For performing a quality assessment, quality scores were calculated.

Results

The total number of patients and implants studied were 37 and 153, respectively, all having had scleroderma. The patients’ ages ranged from 28 to 77 years old, with a mean (SD) age of 58.16 (12.88). All the patients in the case reports and most in the case series study were female. The range of follow‐up duration was from 1 to 10 years. In case report studies, the survival rate was 100%; in case series, it was 89.2%.

Conclusion

The SSc status had no discernible impact on the implant survival rate. Implant‐based treatments in SSc patients should not worsen the overall morbidity and should not conflict with systemic treatments. Before starting implant therapy, a thorough risk assessment is essential, though.

Photodynamic therapy in oral cancer: a review of clinical studies

A significant mortality rate is associated with oral cancer, particularly in cases of late-stage diagnosis. Since the last decades, oral cancer survival rates have only gradually improved despite advances in treatment. This poor success rate is mainly due to the development of secondary tumors, local recurrence, and regional failure. Invasive treatments frequently have a negative impact on the aesthetic and functional outcomes of survivors. Novel approaches are thus needed to manage this deadly disease in light of these statistics. In photodynamic therapy (PDT), a light-sensitive medication called a photosensitizer is given first, followed by exposure to light of the proper wavelength that matches the absorbance band of the photosensitizer. The tissue oxygen-induced cytotoxic free radicals kill tumor cells directly, harm the microvascular structure, and cause inflammatory reactions at the targeted sites. In the case of early lesions, PDT can be used as a stand-alone therapy, and in the case of advanced lesions, it can be used as adjuvant therapy. The current review article discussed the uses of PDT in oral cancer therapy based on recent advances in this field.

COVID-19 Risk Management in Dental Offices: A Review Article

BACKGROUND: As all the dental staff, including nurses and practitioners, are exposed to various routes of contamination due to the novel COVID-19 virus, which is still unknown to the scientific world, developing strategies to reduce the risk of transmission and decontaminate surfaces in a dental office would be of high importance. Although there is still insufficient data on managing this virus in dental offices, several studies have suggested protocols for improving care. AIM: This study aimed to review present investigations and reach a conclusion on what we know and need to know to combat this virus. MATERIALS AND METHODS: In this review, Scopus, PubMed, and MEDLINE databases were searched using the keywords “COVID-19,” “SARS-CoV-2,” “Medical Disinfectants,” “Personal Protective Equipment’s,” and “Surface Decontamination.” Articles were reviewed, and finally, relevant articles published during 2000–2022 were included in the final paper. RESULTS: The present research concluded that using a combination of the face shield and N95 masks protected the eyes, nose, and mouth. To have more efficient protection, water-resistant long-sleeved gowns and gloves were highly suggested. To overcome aerosols, high-performance air filters and ultraviolet were found quite effective. Allowing the patient to use antiseptic mouthwash before starting the treatment could reduce oral microorganisms and the following airborne contamination. CONCLUSION: This review has gathered all available data regarding dentistry and COVID-19 in order to conclude what has been achieved yet in the prevention of this virus through dental offices; however, more investigations are needed to have a definitive protocol against the virus.

Stem cells and common biomaterials in dentistry: a review study

Stem cells exist as normal cells in embryonic and adult tissues. In recent years, scientists have spared efforts to determine the role of stem cells in treating many diseases. Stem cells can self-regenerate and transform into some somatic cells. They would also have a special position in the future in various clinical fields, drug discovery, and other scientific research. Accordingly, the detection of safe and low-cost methods to obtain such cells is one of the main objectives of research. Jaw, face, and mouth tissues are the rich sources of stem cells, which more accessible than other stem cells, so stem cell and tissue engineering treatments in dentistry have received much clinical attention in recent years. This review study examines three essential elements of tissue engineering in dentistry and clinical practice, including stem cells derived from the intra- and extra-oral sources, growth factors, and scaffolds.

Free-Hand versus Surgical Guide Implant Placement

One of the most key areas of dentistry is dental implant surgery. The use of digital equipment and software in dentistry has developed considerably in recent years compared to other fields of medicine. Since examining the advantages and disadvantages of each approach, along with case studies, can help physicians make informed decisions, this review study aims to raise the awareness of dentists to make easier decisions about using guided or free-hand surgery. When planning for a dental implant, one of the most challenging questions that doctors face is which method to use (guided surgery or free-hand). Choosing the right method, such as other clinical considerations, will depend on the individual circumstances of each patient and the preference of the treating physician. Free-hand surgery is a cost-effective method in which the flap is reflected, and, according to the doctor's diagnostic information, an implant is placed, which in many cases is a useful method. Guided surgery has the highest level of accuracy and control, in which osteotomy is designed and printed through a digital surgery guide, and depending on the complexity of the case and the patient's anatomy, it has a higher level of value than free surgery. The surgical guide helps the surgeon make the implant surgery more accurate, safer, simpler, at a lower cost, and in less time. In fact, there are patterns that convey information about the position of the tooth to the dentist before the implant is placed.

Current and Advanced Nanomaterials in Dentistry as Regeneration Agents: An Update

In modern dentistry, nanomaterials have strengthened their foothold among tissue engineering strategies for treating bone and dental defects due to a variety of reasons, including trauma and tumors. Besides their finest physiochemical features, the biomimetic characteristics of nanomaterials promote cell growth and stimulate tissue regeneration. The single units of these chemical substances are small-sized particles, usually between 1 to 100 nm, in an unbound state. This unbound state allows particles to constitute aggregates with one or more external dimensions and provide a high surface area. Nanomaterials have brought advances in regenerative dentistry from the laboratory to clinical practice. They are particularly used for creating novel biomimetic nanostructures for cell regeneration, targeted treatment, diagnostics, imaging, and the production of dental materials. In regenerative dentistry, nanostructured matrices and scaffolds help control cell differentiation better. Nanomaterials recapitulate the natural dental architecture and structure and form functional tissues better compared to the conventional autologous and allogenic tissues or alloplastic materials. The reason is that novel nanostructures provide an improved platform for supporting and regulating cell proliferation, differentiation, and migration. In restorative dentistry, nanomaterials are widely used in constructing nanocomposite resins, bonding agents, endodontic sealants, coating materials, and bioceramics. They are also used for making daily dental hygiene products such as mouth rinses. The present article classifies nanostructures and nanocarriers in addition to reviewing their design and applications for bone and dental regeneration.

Response to Mechanical Cues by Interplay of YAP/TAZ Transcription Factors and Key Mechanical Checkpoints of the Cell: A Comprehensive Review

Many factors including growth factors (GF), scaffold materials, and chemical and physical cues determine the cell behaviors. For many years, growth factors have been considered as the pivotal cell behavior regulators, whereas recent studies emphasize also the key role of physical factors such as mechanical forces, cell shape, surface topographies, and extracellular matrix (ECM) in regulating the cell proliferation, apoptosis, differentiation, etc. through mechanotransduction pathways. In this process, the cell morphology and mechanical properties of the cell's micro/ nano-environments and ECM can be conveyed to the nucleus by regulating transcriptional factors such as Yes-associated protein and transcriptional coactivator with PDZ-binding motif (TAZ). Generally, YAP/TAZ activity is considered as the key factor for the growth of whole organs, however, recent studies have also repeatedly addressed the role of YAP/TAZ in mechanotransduction. In this review, the biological functions of the YAP/TAZ pathway and its contribution to the mechanotransduction and cell behavior regulation in response to the mechanical cues have been summarized. Also, the role of key mechanical checkpoints in the cell including focal adhesions, cytoskeletal tension, Rho small GTPases, and nuclear membrane protein elements involved in the transfer of environmental mechanical cues from the cell surface to the nucleus and their effect in regulating the YAP/TAZ activity are discussed.

Therapeutic applications of herbal/synthetic/bio-drug in oral cancer: An update

Oral cancer, as one of the most prevalent and invasive cancers that invade local tissue, can cause metastasis, and have high mortality. In 2018, around 355,000 worldwide oral cancers occurred and resulted in 177,000 deaths. Estimates for the year 2020 include about 53,260 new cases added to previous year's cases, and the estimated death toll from this cancer in 2020 is about 10,750 deaths more than previous years. Despite recent advances in cancer diagnosis and treatment, unfortunately, 50% of people with cancer cannot be cured. Of course, it should be remembered that the type of treatment used greatly influences patient recovery. There are not many choices when it comes to treating oral cancer. Research efforts focusing on the discovery and evolution of innovative therapeutic approaches for oral cancer are essential. Such traditional methods of treating this type of cancer like surgery and chemotherapy, have evolved dramatically during the past thirty to forty years, but they continue to cause panic among patients due to their side effects. Therefore, it is necessary to study and use drugs that are less risky for the patient as well as to provide solutions to reduce chemotherapy-induced adverse events that prevent many therapeutic risks. As mentioned above, this study examines low-risk therapies such as herbal remedies, biological drugs, and synthetic drugs in the hope that they will be useful to physicians, researchers, and scientists around the world.

Oral microbial biofilms: an update

Human oral cavity (mouth) hosts a complex microbiome consisting of bacteria, archaea, protozoa, fungi and viruses. These bacteria are responsible for two common diseases of the human mouth including periodontal (gum) and dental caries (tooth decay). Dental caries is caused by plaques, which are a community of microorganisms in biofilm format. Genetic and peripheral factors lead to variations in the oral microbiome. It has known that, in commensalism and coexistence between microorganisms and the host, homeostasis in the oral microbiome is preserved. Nonetheless, under some conditions, a parasitic relationship dominates the existing situation and the rise of cariogenic microorganisms results in dental caries. Utilizing advanced molecular biology techniques, new cariogenic microorganisms species have been discovered. The oral microbiome of each person is quite distinct. Consequently, commonly taken measures for disease prevention cannot be exactly the same for other individuals. The chance for developing tooth decay in individuals is dependent on factors such as immune system and oral microbiome which itself is affected by the environmental and genetic determinants. Early detection of dental caries, assessment of risk factors and designing personalized measure let dentists control the disease and obtain desired results. It is necessary for a dentist to consider dental caries as a result of a biological process to be targeted than treating the consequences of decay cavities. In this research, we critically review the literature and discuss the role of microbial biofilms in dental caries.

Oral and maxillofacial trauma in motorcyclists in an Iranian subpopulation

BACKGROUND/AIMS

Road traffic accidents are considered a major cause of oral and maxillofacial trauma. Given that many traumatic injuries and deaths involve motorcyclists, the aim of this study was to investigate this vulnerable group in terms of oral and maxillofacial injuries following accidents.

MATERIALS AND METHODS

This cross-sectional study was conducted on 330 patients with oral and maxillofacial injuries at Shahid Rajaee Hospital in Shiraz, Iran, from April to September 2017. A questionnaire with questions regarding age, gender, helmet use, and driver's license was completed for all the patients and their injury type (including dental injuries). Data were analyzed using descriptive statistics and the chi-squared test with a significance level of 95%.

RESULTS

Of the 330 patients, 291 (88.2%) were male and 39 (11.8%) were female. There were 283 (85.75%) patients aged 21-30 years, and their mean age was 27.2 ± 6.5. Most of them (287, 87%) had not been wearing helmets at the time of the accident. Dental injuries were observed in 168 (50.9%) of the patients. Uncomplicated crown fractures were diagnosed in 25.4% of the patients, luxation injuries in 23.2%, and avulsion in 18.9%. Only 19.9% of the patients under the age of 25 had suffered facial injuries.

CONCLUSION

Most injuries in motorcycle accidents were dental trauma in men due to not wearing a helmet. Dental injuries had the highest frequency of damage.

Do Different Modes of Delivering Postoperative Instructions to Patients Help Reduce the Side Effects of Tooth Extraction? A Randomized Clinical Trial

PURPOSE

Postoperative instructions that are properly delivered can decrease postextraction side effects, such as stress, anxiety, and pain, in patients undergoing dental extraction. This study examined the role of the mode of delivering postoperative instructions in decreasing the side effects of dental extraction and increasing patient satisfaction after the procedure.

MATERIALS AND METHODS

This randomized clinical trial was conducted on a population of 120 patients presenting to the oral and maxillofacial outpatient clinic affiliated with the Shiraz University of Medical Sciences (Shiraz, Iran) in 2015. The patients were randomly assigned to 3 groups of 40 per group. The first group received only verbal instructions after their surgical procedure. The second group received only written instructions. The third group received verbal and written instructions. Details on the patient's age, gender, and formal education were recorded before the operation using a questionnaire. The second part of the questionnaire was completed by patients 1 week after their tooth extraction and recorded their postoperative pain, bleeding, swelling, and satisfaction. Data were analyzed using the Mann-Whitney test, Kruskal-Wallis test, χ² test, and analysis of covariance at a significance level of 95%.

RESULTS

Of the 120 participants, 77 were women and 43 were men; the participants' mean age was 36.45 ± 10.69 years. The results showed that the mode of delivering instructions had a marked relation with pain and patient satisfaction. Pain intensity was significantly higher in the verbal instructions group compared with the written instructions (P = .002) and verbal plus written instructions (P = .000) groups.

CONCLUSION

The mode of delivering postoperative instructions meaningfully affected pain intensity and general patient satisfaction. Patients who received verbal instructions reported the most intense pain and the least satisfaction, and patients who received verbal and written instructions were the most satisfied.