Ultrasonic vs. hand instrumentation in periodontal therapy: clinical outcomes

Therapeutic effect of mesenchymal stem cell-derived exosome therapy for periodontal regeneration: a systematic review and meta-analysis of preclinical trials

BACKGROUND

To assess the therapeutic effects of mesenchymal stem cell (MSC)-derived exosome therapy on periodontal regeneration and identify treatment factors associated with enhanced periodontal regeneration in recent preclinical studies.

METHODS

Searches were conducted in PubMed, Cochrane Library, EMBASE, and Web of Science databases until October 10, 2024. A risk of bias (ROB) assessment was performed using the SYRCLE tool. Osteogenic-related parameters were used as the primary outcome measures.

RESULTS

In total, 1360 articles were identified, of which 17 preclinical studies were based on MSC-derived exosome therapy, and they demonstrated a beneficial effect on BV/TV (SMD = 13.99; 95% Cl = 10.50, 17.48; p < 0.00001), CEJ-ABC (SMD = -0.22; 95% Cl = -0.31, -0.13; p < 0.00001), BMD (SMD = 0.29; 95% Cl = 0.14, 0.45; p = 0.0002), and Tp.Sp (SMD = -0.08; 95% Cl= -0.15, -0.02; p = 0.02) compared with the control group. However, no significant differences were observed in Tp.Th (SMD = 0.03; 95% CI = 0.00, 0.07; p = 0.09) between the exosome-treated group and control group. Additionally, subgroup analysis indicated that preconditioned exosomes (p = 0.03) significantly improved BV/TV. In contrast, there were no significant differences in the enhancement of BV/TV with respect to the application method (p = 0.29), application frequency (p = 0.10), treatment duration (p = 0.15), or source of MSCs (p = 0.31).

CONCLUSIONS

MSC-derived exosomes show great promise for enhancing the quality of periodontal regeneration. However, more standardized and robust trials are needed to reduce heterogeneity and bias across studies and to confirm the therapeutic parameters associated with the enhancement of periodontal regeneration by MSC-derived exosomes.

REGISTRATION

CRD42024546236.

A Survey of Dental Hygiene Pre-Clinic Instrumentation Selection and Sequence

OBJECTIVES

The purpose of this study was to assess the selection and sequence of dental hygiene instruments taught during dental hygiene pre-clinical education in the United States.

METHODS

Exempt status was received from the University of New Mexico's IRB (ID 21-336). A survey was developed with questions to be answered involving decisions for clinical teaching and sequencing on various assessment and implementation instruments during pre-clinic education. The instrument was 11 questions with multiple choice, ranking and short answer. A survey link was included through email invitation and successfully sent to 301 accredited dental hygiene programme directors in the United States. Results were collected and analysed through descriptive statistics.

RESULTS

Forty-three of the invited participants completed the survey, a 14% response rate. Almost half (n = 24) of the participants chose to teach the periodontal probe first and 19 chose the explorer. Twenty-five participants selected they teach the sickle scalers first, 14 teach the universal curette scalers first and 4 teach the Gracey curette scalers first. All participants teach electronically powered scalers with 33 teaching after hand instrumentation and 8 before.

CONCLUSIONS

Results from this study emphasise that educators teach clinical instrumentation from professional opinion, but no attestation specifically suggests the use of evidence-based pedagogical standards for clinical teaching. Dental hygiene programmes could benefit from further research on pre-clinic instrument selection and sequencing as a way of standardised clinical teaching. These clinical implications could advance the science for standardised teaching of clinical instrumentation and sequencing in dental hygiene education.

The Effects of Ultrasonic Scaling and Air-Abrasive Powders on the Topography of Implant Surfaces: Scanning Electron Analysis and In Vitro Study

OBJECTIVES

 This in vitro study aimed to investigate the impact of bicarbonate air-abrasive powders and ultrasonic scaling with stainless steel tips on the micro- and nanotopography and roughness of three different implant-abutment junction titanium surfaces.

MATERIALS AND METHODS

 Three types of sterile and decontaminated titanium surfaces (RS, UTM, XA) were used for analysis. Nine disks per surface type were subjected to micro- and nanotopography analysis, scanning electron microscopy (SEM), roughness analysis, and fibroblast cultivation. Ultrasonic debridement and air polishing were performed on the surfaces. Human dermal fibroblasts were cultured on the surfaces for 5 days.

STATISTICAL ANALYSIS

 Data analysis adhered to ISO 25178 standards for surface texture assessment. SEM micrographs were used to reconstruct areas for extracting roughness parameters. Excel and Mex 6.0 software were utilized for quantitative and stereoscopic analysis.

RESULTS

 The study found varying effects on surface roughness posttreatment. RS Disco samples exhibited higher surface roughness compared with UTM and XA samples, both in average and nanoscale roughness. Decontamination led to increased surface roughness for all samples, particularly RS Disco. Fibroblast growth tests revealed enhanced cell network formation on decontaminated discs, possibly due to increased nanoscale roughness or the presence of bicarbonate salts.

CONCLUSION

 The study underscores the complex interplay between surface topography, microbial biofilm, and treatment efficacy in peri-implant disease management. While smoother surfaces may resist biofilm accumulation, increased nanoscale roughness postdecontamination can enhance fibroblast attachment and soft tissue integration. This dichotomy highlights the need for tailored treatment protocols that consider material-specific factors, emphasizing that successful implant therapy should balance microbial control with conducive surface characteristics for long-term osseointegration and soft tissue stability.

Effects of different periodontal interventions on the risk of adverse pregnancy outcomes in pregnant women: a systematic review and network meta-analysis of randomized controlled trials

Background

Periodontal disease is widespread among pregnant women, and it is possible that taking action to improve oral health conditions can make improvements in adverse pregnancy outcomes. Herein, we summarize the recent evidence using a network meta-analysis to assess the effects of different periodontal treatment intervention strategies on the risk of adverse pregnancy outcomes in pregnant women.

Materials and methods

Randomized controlled trials were retrieved from PubMed, Web of Science, Embase, and Cochrane Library databases. After literature screening, data extraction, and quality evaluation of the included literature were performed, the R studio 4.2.2 "netmeta" package was used for the network meta-analysis.

Results

A total of 20 studies were included, and 5 adverse pregnancy outcomes (preterm birth, low birth weight, preterm birth and/or low birth weight infants, small for gestational age, and pre-eclampsia) were considered to examine the effects of different periodontal treatment interventions strategies on the risk of the abovementioned outcome indicators. The results of the network meta-analysis demonstrated that the three periodontal treatment intervention strategies of sub- and/or supra-gingival scaling and root planing + chlorhexidine rinsing (SRP + CR), sub- and/or supra-gingival scaling and root planing+chlorhexidine rinsing + tooth polishing and plaque control (SRP + CR + TP), and sub- and/or supra-gingival scaling and root planing +sonic toothbrush + tooth polishing and plaque control (SRP + ST + TP) reduced the risk of preterm birth [odds ratio (OR) = 0.29, 95% confidence interval (CI) (0.10-0.88), OR = 0.25, 95CI% (0.10-0.63), OR = 0.28, 95CI% (0.11-0.69), respectively]. In addition, two periodontal treatment intervention strategies, SRP + CR and SRP + CR + TP, were effective methods in terms of the risk of preterm birth and/or low birth weight [OR = 0.18, 95CI% (0.06-0.52), OR = 0.31, 95CI% (0.12-0.79)].

Conclusion

The available evidence suggests that the risk of preterm birth and preterm birth and/or low birth weight can be reduced with certain periodontal treatment intervention strategies. Future studies should focus on optimizing intervention strategies and the optimal timing for different periods of pregnancy, in order to provide a reference for pregnant women's healthcare.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=407901, CRD42023407901.

Efficacy of injectable platelet-rich fibrin (i-PRF) as a novel vehicle for local drug delivery in non-surgical periodontal pocket therapy: A randomized controlled clinical trial

Background

The vehicle in a local drug delivery (LDD) system plays a vital role in delivering the active drug component at the diseased site. Liquid/injectable platelet-rich fibrin (i-PRF), an autologous fibrin matrix, might be used as a vehicle to enmesh drugs and deliver locally at the periodontally diseased sites. This study evaluated the efficacy of the drug (ciprofloxacin [Cip])-loaded i-PRF as a LDD system adjunct to subgingival debridement in subjects with periodontal pockets.

Methods

In a parallel design study, 79 periodontally diseased pocket sites were randomized to 3 groups: group 1 (n=25), scaling and root planing (SRP)+i-PRF+Cip; group 2 (n=25), SRP+i-PRF; group 3 (n=25), SRP without any adjunctive intervention. Clinical parameters (probing depth [PD], clinical attachment level [CAL], gingival index [GI], plaque index [PI]) and microbial quantification (relative quantification of levels of Aggregatibacter actinomycetemcomitans) were assessed from baseline to 6th and 12th weeks of follow-up.

Results

All the treatment groups showed significant improvements in the clinical and microbial parameters assessed. Group 1 showed significantly higher PD and GI reduction with CAL gain and decreased in relative levels of A. actinomycetemcomitans in the 12th week, followed by group 2 compared to group 3.

Conclusion

Thus, within the limits of this study, it can be concluded that i-PRF could be considered a potential LDD vehicle for the delivery of ciprofloxacin in periodontal pocket therapy.

Clinical Efficacy of Scaling and Root Planing With Placental Extract Gel Under Magnification in Chronic Periodontitis Patients: A Split-Mouth Study

Background Chronic localized periodontitis is a prevalent and persistent inflammatory condition in which there is the gradual degradation of the gingiva, periodontal ligament fibers, and alveolar bone loss. The objectives of periodontal therapy encompass not solely the elimination of local factors from the periodontal pocket but also the eradication of the dysbiotic microbial milieu to restore periodontal health. The present study aimed to compare the efficacy of scaling and root planing (SRP) with and without the placement of placental extract gel in the therapeutic management of chronic localized periodontitis under magnification. Materials and methods The present investigation encompassed 40 sites in 20 systemically healthy patients with chronic localized periodontitis. The allocation of the sites was done randomly, resulting in two distinct groups: group I (test site) and group II (control site). Group I was subjected to SRP, followed by the placement of placental extract gel, while group II solely received SRP. Clinical evaluations of pocket probing depth, plaque index, relative attachment level (RAL), gingival index (GI), and bleeding on probing (BoP) were performed at each site at baseline, six weeks, and three months. Results Placental extract gel as an accompaniment to SRP showed significant improvement in clinical parameters like pocket probing depth, RAL, GI, and BoP. Conclusion Placental extract gel may significantly act as a local drug delivery agent in the treatment of localized periodontal pockets.

Root surface roughness evaluation following application of different periodontal instruments and Er:YAG laser: A profilometry and SEM study

AIM

The aim of the present study was to evaluate the efficacy of 30°-angled Er:YAG laser tip and different periodontal instruments on root surface roughness and morphology in vitro.

METHODS

Eighteen bovine teeth root without carious lesion were decoronated from the cementoenamel junction and seperated longitidunally. A total of 36 obtained blocks were mounted in resin blocks and polished with silicon carbide papers under water irrigation. These blocks were randomly assigned into 3 treatment groups. In Group 1, 30°-angled Er:YAG laser (2.94 μm) tip was applied onto the blocks with a 20 Hz, 120 mJ energy output under water irrigation for 20 s. In Groups 2 and 3, the same treatment was applied to the blocks with new generation ultrasonic tip and conventional curette apico-coronally for 20 s with a sweeping motion. Surface roughness and morphology were evaluated before and after instrumentation with a profilometer and SEM, respectively.

RESULTS

After instrumentation, profilometric analysis revealed significantly higher roughness values compared to baseline in all treatment groups(p < 0.05). Laser group revealed the roughest surface morphology followed by conventional curette and new generation ultrasonic tip treatment groups (p < 0.05). In SEM analysis, irregular surfaces and crater defects were seen more frequently in the laser group.

CONCLUSION

Results of the study showed that the use of new generation ultrasonic tip was associated with smoother surface morphology compared to 30°-angled Er-YAG laser tip and conventional curette. Further in vitro and in vivo studies with an increased sample size are necessary to support the present study findings.

Microcin C7-laden modified gelatin based biocomposite hydrogel for the treatment of periodontitis

Periodontitis is an oral disease with the highest incidence globally, and plaque control is the key to its treatment. In this study, Microcin C7 was used to treat periodontitis, and a novel injectable temperature-sensitive sustained-release hydrogel was synthesized as an environmentally sensitive carrier for drug delivery. First, modified gelatin was formed from gelatin and glycidyl methacrylate. Then, Microcin C7-laden hydrogel was formed from cross-linking with double bonds between modified gelatin, N-isopropyl acrylamide, and 2-Methacryloyloxyethyl phosphorylcholine through radical polymerization, and the model drug Microcin C7 was loaded by electrostatic adsorption. The hydrogel has good temperature sensitivity, self-healing, and injectable properties. In vitro results showed that the hydrogel could slowly and continuously release Microcin C7 with good biocompatibility and biodegradability, with a remarkable antibacterial effect on Porphyromonas gingivalis. It also confirmed the antibacterial and anti-inflammatory effects of Microcin C7-laden hydrogel in a periodontitis rat model. The results showed that Microcin C7-laden hydrogel is a promising candidate for local drug delivery systems in periodontitis.

Effectiveness of typodont, quail egg and virtual simulation for ultrasonic periodontal scaling teaching among pre-clinical students: a randomized trial

BACKGROUND

This study aimed to compare the efficacy of three different techniques, namely virtual simulation technology (VS), traditional pathological typodont (TT), and quail egg (QE), in pre-clinical training of periodontal ultrasonic scaling. It also aimed to propose an integrated teaching approach for ultrasonic scaling teaching.

METHODS

This single-blind randomized multi-arm trial enrolled 108 fourth-year students from Guanghua School of Stomatology at Sun Yat-sen University. The participants were randomly, evenly assigned to VS, TT, or QE group. First, the participants received theoretical review on ultrasonic scaling and demonstrative teaching. Then in the 90-minute operation training by group, students used traditional typodont equipped in head-simulators, raw quail eggs, or scaling module of the UniDental VS system respectively. Then all participants practiced on pathological models for 30 min. In the final operation examination, participants were instructed to remove the supra- and sub-gingival calculi pre-set on designated teeth by ultrasonic scalers within 30 min. Their performances were evaluated by residual calculus rate and a multi-perspective scoring scale. After the examination, questionnaires were provided to assess the teaching effects of each method and the fidelity of VS. Statistical analysis was carried out using one-way, two-way ANOVA, and multiple t-test.

RESULTS

Students in VS group had significant higher total test scores than QE group (87.89 ± 6.81, 83.53 ± 8.14) and TT group (85.03 ± 6.81). VS group scored higher in several dimensional comparisons with the other two groups, especially in difficult situations. QE group had higher scores particularly in force application and supra-gingival scaling. TT group scored the highest in pivot stability practice and body position training. Students gave higher scores when assessing the fidelity of VS than experienced teachers.

CONCLUSION

The study highlights the importance of specialized pre-clinical training on ultrasonic scaling for dental students. The methods adopted in current study (VS, TT and QE) each offered unique advantages in education, which can be combined to create an integrative teaching procedure. This procedure aims to provide an effective, advisable and normative pre-clinical training procedure for ultrasonic scaling. By utilizing the strengths of each method, dental educators can deliver high-quality training and ensure that students are well-prepared for clinical practice.

Effects of Antimicrobial Photosensitizers of Photodynamic Therapy (PDT) to Treat Periodontitis

Antimicrobial photodynamic therapy or aPDT is an alternative therapeutic approach in which lasers and different photosensitizing agents are used to eradicate periodontopathic bacteria in periodontitis. Periodontitis is a localized infectious disease caused by periodontopathic bacteria and can destroy bones and tissues surrounding and supporting the teeth. The aPDT system has been shown by in vitro studies to have high bactericidal efficacy. It was demonstrated that aPDT has low local toxicity, can speed up dental therapy, and is cost-effective. Several photosensitizers (PSs) are available for each type of light source which did not induce any damage to the patient and are safe. In recent years, significant advances have been made in aPDT as a non-invasive treatment method, especially in treating infections and cancers. Besides, aPDT can be perfectly combined with other treatments. Hence, this survey focused on the effectiveness and mechanism of aPDT of periodontitis by using lasers and the most frequently used antimicrobial PSs such as methylene blue (MB), toluidine blue ortho (TBO), indocyanine green (ICG), malachite green (MG) (Triarylmethanes), erythrosine dyes (ERY) (Xanthenes dyes), rose bengal (RB) (Xanthenes dyes), eosin-Y (Xanthenes dyes), radachlorin group and curcumin. The aPDT with these PSs can reduce pathogenic bacterial loads in periodontitis. Therefore, it is clear that there is a bright future for using aPDT to fight microorganisms causing periodontitis.

Metal-organic gels: recent advances in their classification, characterization, and application in the pharmaceutical field

Metal-organic gels (MOGs) are a type of functional soft substance with a three-dimensional (3D) network structure and solid-like rheological behavior, which are constructed by metal ions and bridging ligands formed under the driving force of coordination interactions or other non-covalent interactions. As the homologous substances of metal-organic frameworks (MOFs) and gels, they exhibit the potential advantages of high porosity, flexible structure, and adjustable mechanical properties, causing them to attract extensive research interest in the pharmaceutical field. For instance, MOGs are often used as excellent vehicles for intelligent drug delivery and programmable drug release to improve the clinical curative effect with reduced side effects. Also, MOGs are often applied as advanced biomedical materials for the repair and treatment of pathological tissue and sensitive detection of drugs or other molecules. However, despite the vigorous research on MOGs in recent years, there is no systematic summary of their applications in the pharmaceutical field to date. The present review systematically summarize the recent research progress on MOGs in the pharmaceutical field, including drug delivery systems, drug detection, pharmaceutical materials, and disease therapies. In addition, the formation principles and classification of MOGs are complemented and refined, and the techniques for the characterization of the structures/properties of MOGs are overviewed in this review.

Decoding the role of long non-coding RNAs in periodontitis: A comprehensive review

Periodontitis is an inflammatory disease characterized by the pathological loss of alveolar bone and the adjacent periodontal ligament. It is considered a disease that imposes a substantial health burden, with an incidence rate of 20-50%. The etiology of periodontitis is multifactorial, with genetic factors accounting for approximately half of severe cases. Studies have revealed that long non-coding RNAs (lncRNAs) play a pivotal role in periodontitis pathogenesis. Accumulating evidence suggests that lncRNAs have distinct regulatory mechanisms, enabling them to control numerous vital processes in periodontal cells, including osteogenic differentiation, inflammation, proliferation, apoptosis, and autophagy. In this review, we summarize the diverse roles of lncRNAs in the pathogenesis of periodontitis, shedding light on the underlying mechanisms of disease development. By highlighting the potential of lncRNAs as biomarkers and therapeutic targets, this review offers a new perspective on the diagnosis and treatment of periodontitis, paving the way for further investigation into the field of lncRNA-based therapeutics.

Effect of forceful suction and air disinfection machines on aerosol removal

BACKGROUNDS

Dental procedures involving drilling and grinding can produce a significant amount of suspended aerosol particles (PM) and bioaerosols. This study aims to analyze the size and concentration of aerosol particles generated during drilling and to investigate the effectiveness of two air exchange systems, namely forceful suction (FS) and air disinfection machines (DM), in removing PM.

METHODS

For this study, 100 extracted permanent teeth were collected and divided into three groups: without suction (n = 50), suction with forceful suction (n = 25), and suction with air disinfection machines (n = 25). The removal rate of suspended aerosol particles was analyzed using particle counters and air data multimeter.

RESULTS

When drilling and grinding were performed without vacuum, 0.75% of the aerosol particles generated were PM2.5-10, 78.25% of total suspended aerosol particles (TSP) were PM2.5, and 98.68% of TSP were PM1. The nanoanalyzer measurements revealed that the aerodynamic diameter of most aerosol particles was below 60 nm, with an average particle diameter of 52.61 nm and an average concentration of 2.6*1011 ultrafine aerosol particles. The air change per hour (ACH) was significantly lower in the air disinfection machines group compared to the forceful suction group. Additionally, the number of aerosol particles and mass concentration was significantly lower in the air disinfection machines group compared to the forceful suction group in terms of PM2.5 levels. However, the forceful suction group also reduced the mass concentration in PM10 level than the air disinfection machines group.

CONCLUSION

In conclusion, the air exchange system can reduce the aerosol particles generated during drilling and grinding. Comparing the two air exchange systems, it was found that the air disinfection machines group reduces the number of aerosol particles and mass concentration in PM2.5 levels, while the forceful suction group reduces the mass concentration in PM10 level.

The efficacy of subgingival air polishing and subgingival debridement in periodontal support therapy: a meta-analysis

OBJECTIVE

To assess whether there is sufficient evidence of a difference in efficacy between subgingival air polishing (SubAP) and subgingival debridement as periodontal support treatment. The systematic review protocol was registered in the PROSPERO database under no. CRD42020213042.

METHODS

A comprehensive search was conducted using eight online databases to develop straightforward clinical questions and search strategies, from their inception to 27 January 2023. The references of identified reports were also retrieved for inclusion in the analysis. The risk-of-bias of the included studies was evaluated using the Revised Cochrane Risk-of-Bias tool (RoB 2). A meta-analysis was performed on five clinical indicators using the Stata 16 software.

RESULTS

Twelve randomized controlled trials were ultimately included, and most included studies had varying degrees of risk-of-bias. The results of the meta-analysis indicated that there was no significant difference between SubAP and subgingival scaling in terms of improving probing depth (PD), clinical attachment loss (CAL), plaque index (PLI), and bleeding on probing% (BOP%). The results of the visual analogue scale score analysis indicated that SubAP produced less discomfort than did subgingival scaling.

DISCUSSION

SubAP can provide better treatment comfort than subgingival debridement. There was no significant difference in the efficacy of the two modalities in improving PD, CAL, and BOP% in supportive periodontal therapy.

CONCLUSION

Currently, evidence for assessing the difference in the efficacy of SubAP and subgingival debridement in improving the PLI is insufficient, and further high-quality clinical studies are needed.

Efficacy of active noise-canceling headphones in patients undergoing ultrasonic scaling

PURPOSE

Dental fear hinders patients from receiving appropriate dental treatment. In particular, the noise generated by high-speed air turbines and ultrasonic scalers can adversely affect patients. Many efforts have been made to reduce the discomfort caused by noise, but no methods are definitively recommended. The purpose of this study was to determine the efficacy of active noise-canceling (ANC) headphones in reducing the pain and discomfort associated with dental scaling.

METHODS

Fifty-five patients requiring scaling and root planing, aged ≥19 years and showing no auditory problems, were included. Scaling was performed for the bilateral maxillary molars and premolars while patients wore headphones, with ANC turned either on or off. The degree of noise and pain reduction in the on and off conditions were surveyed using a visual analog scale (VAS). The Wilcoxon signed-rank test was performed to compare noise- and pain-related discomfort with ANC turned on and off.

RESULTS

The sample included 28 men and 27 women with a mean age of 45.45±13.12 years. The average noise-related discomfort score was 3.84±2.12 and 2.95±1.99 when noise-canceling was turned off and on, respectively, with a statistically significant difference (P<0.05). Similarly, the average pain-related discomfort score was 3.78±2.00 and 3.09±1.96 when noise-canceling was turned off and on, respectively, which was a statistically significant difference (P<0.05).

CONCLUSIONS

The use of ANC headphones seems to reduce the discomfort caused by noise and pain in patients undergoing scaling.

TRIAL REGISTRATION

Clinical Research Information Service Identifier: KCT0007093.

In Vitro Evaluation of the Different Supragingival Prophylaxis Tips on Enamel Surfaces

Objective: Periodontal instrumentation during supragingival prophylaxis may increase enamel surface roughness, which may lead to increased dental biofilm accumulation and demineralization of the enamel. The aim of this study was to evaluate the changes of the enamel surface profilometrically after the application of different scaler tips used for the professional supragingival prophylaxis. Materials and methods: Forty-eight enamel block samples obtained from extracted human maxillary premolar teeth were prepared and randomly assigned to four different treatment groups. Each treatment group was instrumented by the same clinician with different tools as Group 1: Er:YAG laser chisel tip, Group 2: scaler, Group 3: new generation universal curette; and Group 4: ultrasonic device. Sample surfaces were evaluated with a profilometer before and after instrumentations and after the polishing process. Results: Baseline roughness of the prepared enamel samples was similar between the groups. After instrumentation and polishing, the Er:YAG laser chisel tip revealed the most irregular surface morphology, whereas the new generation curette induced the smoothest surface. Conclusions: New generation universal curette is a promising tool, which can be used safely for supragingival calculus removal without the need for polishing on enamel surfaces.

Weak direct current exerts synergistic effect with antibiotics and reduces the antibiotic resistance: An in vitro subgingival plaque biofilm model

BACKGROUND AND OBJECTIVE

Weak direct current (DC) exerts killing effect and synergistic killing effect with antibiotics in some specific bacteria biofilms. However, the potential of weak DC alone or combined with periodontal antibiotics in controlling periodontal pathogens and plaque biofilms remains unclear. The objective of this study was to investigate whether weak DC could exert the anti-biofilm effect or enhance the killing effect of metronidazole (MTZ) and/or amoxicillin-clavulanate potassium (AMC) on subgingival plaque biofilms, by constructing an in vitro subgingival plaque biofilm model.

METHODS

The pooled subgingival plaque and saliva of patients with periodontitis (n = 10) were collected and cultured anaerobically on hydroxyapatite disks in vitro for 48 h to construct the subgingival plaque biofilm model. Then such models were stimulated with 0 μA DC alone (20 min/12 h), 1000 μA DC alone (20 min/12 h), 16 μg/ml MTZ, 16 μg/ml AMC or their combination, respectively. Through viable bacteria counting, metabolic activity assay, quantitative real-time PCR absolute quantification and 16S rDNA sequencing analysis, the anti-biofilm effect of 1000 μA DC and enhanced killing effects of 1000 μA DC combined with antibiotics (MTZ, AMC or MTZ+AMC) were explored.

RESULTS

The old subgingival plaque model (48 h) had no significant difference in total bacterial loads from subgingival plaque in situ, which achieved a similarity of 80%. The 1000 μA DC plus MTZ or AMC for 12 h showed a stronger synergistic killing effect than the same combination for 20 min. The metabolic activity was reduced to the lowest by DC plus MTZ+AMC, as 37.4% of that in the control group, while average synergistic killing effect reached 1.06 log units and average total bacterial loads decreased to 0.87 log units. Furthermore, the relative abundance of the genera Porphyromonas, Prevotella, Treponema_2, and Tannerella were decreased significantly.

CONCLUSION

The presence of weak DC (1000 μA) improved the killing effect of antibiotics on subgingival plaque biofilms, which might provide a novel strategy to reduce their antibiotic resistance.

Inhibitory effect of polysaccharides extracted from Changbai Mountain Ganoderma lucidum on periodontal inflammation

As the main bioactive substance of Ganoderma lucidum, Ganoderma lucidum polysaccharide (GLP) has anti-inflammatory, antibacterial, and other biological activities. Studies have shown that GLP can regulate the expression of multiple inflammatory cytokines in different inflammatory models and diseases as part of the anti-infection immune response. We extracted crude Changbai Mountain Ganoderma lucidum polysaccharides (CGLPs), analyzed their physical and chemical properties, and then applied them to the periodontitis model to verify whether they have an inhibitory effect on mouse periodontitis. CGLP was determined to be a heteropolysaccharide with dextran as the main component. Its molecular weight was 17.40 kDa. In vivo experiments in mice showed that CGLP can inhibit the alveolar bone loss and reduced inflammation caused of periodontitis by regulating the expression of the inflammatory factors IL-1β, TNF-α, and IL-10 in a concentration-dependent manner.

Periodontal instrumentation technique: an exploratory analysis of clinical outcomes and financial aspects

Objective This exploratory post hoc analysis sought to investigate clinical outcomes comparing non-surgical treatment for periodontal disease using exclusively hand instruments, exclusively ultrasonic instruments or a combination approach. Differences in time efficiency and equipment use with each treatment method were evaluated.Methods In total, 55 patients with periodontitis were treated across two studies (randomised controlled trial and cohort study) with non-surgical periodontal therapy using hand instruments (HI), ultrasonic instruments (UI) or a combination approach (CI). All patients were re-evaluated 90 days after treatment. Clinical parameters, time taken and financial implications of non-surgical periodontal therapy were explored with a descriptive analysis within this post hoc analysis.Results There were no clinically relevant differences in clinical parameters across all groups at day 90. Inter-group comparisons showed no clinically relevant differences in treatment outcome between groups. UI required less time on average to complete treatment compared to HI. UI provided using a half mouth approach had fewest overall episodes of expenditure and lowest maintenance costs.Conclusions Comparison of clinical outcomes between HI, UI and CI yielded no clinically relevant differences. When comparing HI and UI, UI had a shorter treatment time on average. Full mouth treatment was associated with the least patient visits. UI was least costly on a recurring basis.

Hand instrumentation provides improved tissue response over ultrasonic scaler and substantiates safe dental practice: An in vivo study in rats

OBJECTIVE

The aim of this study was to evaluate the effectiveness of hand debridement (HD) versus ultrasonic dental scaler (UDS) for the treatment of experimental periodontitis (EP) in rats.

MATERIAL AND METHODS

Thirty 3-month-old male rats were used. EP was induced around the mandibular first molars (right and left). Seven days after induction, the treatments with either HD (n = 30) or UDS (n = 30) were randomly performed in each molar. Euthanasia were performed at 7, 15, and 30 days after treatment. Histometric (percentage of bone in the furcation [PBF]), histopathological, and immunohistochemical (for detection of tartrate-resistant acid phosphatase [TRAP] and osteocalcin [OCN]). Parametric data (PBF and TRAP) was analyzed by One-way ANOVA followed by Tukey's post-test. OCN was analyzed by Kruskal-Wallis followed by Student-Newman-Keuls post-test. The level of significance was 5%.

RESULTS

Group HD presented higher PBF and lower TRAP-immunolabeling at 30 days as compared with UDS in the same period (p≤0.05). Group HD presented higher OCN immunolabeling at 30 days as compared with 7 and 15 days (p≤0.05). Persistent and exacerbated inflammatory process was observed in some specimens from group UDS at 30 days, as well as the bone trabeculae presented irregular contour, surrounded by many active osteoclasts.

CONCLUSION

Nonsurgical periodontal therapy with HD resulted in higher PBF and lower expression of TRAP as compared with UDS. Also, HD increased the expression of OCN over time.

Ultra-small molybdenum-based nanodots as an antioxidant platform for effective treatment of periodontal disease

Periodontal disease (PD) is a local inflammatory disease with high morbidity, manifesting tissue destruction results from inflammation of the host immune response to bacterial antigens and irritants. The supportive function of connective tissue and skeletal tissue can be jeopardized without prompt and effective intervention, representing the major cause of tooth loss. However, traditional treatments exhibited great limitations, such as low efficacies, causing serious side effects and recurrent inflammatory episodes. As a major defense mechanism, reactive oxygen species (ROS) play important roles in the pathological progression of PD. Antioxidant therapy is widely believed to be an effective strategy for ROS-triggered diseases, including oxidative stress-induced PD. Most antioxidants can only scavenge one or a few limited kinds of ROS and cannot handle all kinds. In addition, current antioxidant nanomaterials present limitations associated with toxicity, low stability, and poor biocompatibility. To this end, we develop ultra-small molybdenum-based nanodots (MoNDs) with strong ROS in oxidative stress-induced PD. To the best of our knowledge, this is the first time that MoNDs have been used for PD. In the present study, MoNDs have shown extremely good therapeutic effects as ROS scavengers. Spectroscopic and in vitro experiments provided strong evidence for the roles of MoNDs in eliminating multiple ROS and inhibiting ROS-induced inflammatory responses. In addition, the mouse model of PD was established and demonstrated the feasibility of MoNDs as powerful antioxidants. It can alleviate periodontal inflammation by scavenging multiple ROS without obvious side effects and exhibit good biocompatibility. Thus, this newly developed nanomedicine is effective in scavenging ROS and inhibiting M1 phenotypic polarization, which provides promising candidates for the treatment of PD.

A Study on the Use of Phase Transition Lysozyme-Loaded Minocycline Hydrochloride in the Local Treatment of Chronic Periodontitis

Periodontitis is the most important oral disease causing human tooth loss. Although supragingival and subgingival scaling is the main strategy of periodontitis clinical treatments, drug treatment has an indispensable auxiliary role to some degree. Periodontitis medical treatment is divided into systemically administered treatments and local periodontally administered treatments. Compared with systemic administration, local administration can increase local drug concentrations, reduce dosages, and prolong action times while also improving patient compliance and avoiding possible adverse effects due to systemic administration responses. However, some studies show that minocycline ointment, a clinical local drug commonly used in periodontal pockets, has an unstable release rate; 80% of the drug is usually released within 2-3 days after pocket placement. This release is not conducive to controlling periodontal infection and may hinder the periodontal tissue repair and regeneration. Therefore, choosing a suitable carrier for minocycline hydrochloride is necessary to control its local release in periodontal tissue. Phase transition lysozyme (PTL) has been widely used in many studies and the development of macromolecular carrier material, and we selected PTL as the carrier for minocycline hydrochloride drugs because of its good biocompatibility, good drug-carrying capacity, and stable release. Due to its release characteristics and simple preparation, PTL is a promising carrier material.

The circular RNA circ_0099630/miR-940/receptor-associated factor 6 regulation cascade modulates the pathogenesis of periodontitis

Background/purpose

Materials and methods

Results

Conclusion

HMBOX1 attenuates LPS-induced periodontal ligament stem cell injury by inhibiting CXCL10 expression through the NF-κB signaling pathway

Homeobox containing 1 (HMBOX1) is a member of the homeobox transcription factor family that has been reported to serve an important role in numerous biological processes. The present study aimed to determine the role of HMBOX1 in the pathogenesis of periodontitis. Human periodontal ligament stem cells (hPDLSCs) were treated with liposaccharide (LPS) and transfected with a HMBOX1 overexpression (Ov-HMBOX1) plasmid or small interfering (si)-C-X-C motif chemokine ligand 10 (CXCL10) plasmids. The effects of Ov-HMBOX1 on cell proliferation, inflammation and apoptosis were subsequently investigated using Cell Counting Kit-8, ELISA for analysis of IL-6, TNF-α and IL-1β levels, TUNEL and western blotting assays for analysis of Bcl-2, Bax, cleaved caspase-3 and caspase-3 levels, respectively. Furthermore, the potential effects of HMBOX1 on the mRNA and protein levels of CXCL10 and the NF-κB signaling pathway were investigated by using reverse transcription-quantitative PCR and western blotting. Finally, the physiological processes of lipopolysaccharide (LPS)-induced hPDLSCs overexpressing HMBOX1 were assessed following treatment with phorbol 12-myristate 13-acetate (PMA), a NF-κB agonist. The results revealed that Ov-HMBOX1 transfection promoted proliferation whilst alleviating inflammation and apoptosis in LPS-induced hPDLSCs. Ov-HMBOX1 reduced the expression of CXCL10 by suppressing the NF-κB signaling pathway. PMA treatment inhibited the proliferation of LPS-induced hPDLSCs transfected with Ov-HMBOX1, which was reversed by transfection with si-CXCL10. In conclusion, results of the present study provided evidence that HMBOX1 can attenuate LPS-induced hPDLSC injury by downregulating CXCL10 expression via the NF-κB signaling pathway, which may provide a novel insight into the development of potentially novel treatment strategies for periodontitis.

The Effects of Ultrasonic Scaling and Air-Abrasive Powders on the Decontamination of 9 Implant-Abutment Surfaces: Scanning Electron Analysis and In Vitro Study

(1) Background: The aim of this study is to understand from a microscopic point of view whether bicarbonate air-abrasive powders associated with ultrasonic instruments can decontaminate nine different surfaces used for the abutment/implant junction. Fibroblast growth was carried out on decontaminated surface in order to understand if there are significative differences in terms of biocompatibility. (2) Methods: After taking samples of patient plaque, nine different surfaces were contaminated and analyzed by SEM, then their wettability was evaluated. Fibroblasts were cultured on the decontaminated surfaces to understand their ability to establish a connective tissue seal after decontamination. The results were analyzed from a statistical point of view to hypothesize a mathematical model capable of explaining the properties of the surfaces. (3) Results: A negative correlation between roughness and contamination has been demonstrated, whereas a weak correlation was observed between wettability and decontamination capacity. All surfaces were topographically damaged after the decontamination treatment. Grade 5 titanium surfaces appear tougher, whereas anodized surfaces tend to lose the anodizing layer. (4) Conclusions: further studies will be needed to fully understand how these decontaminated surfaces affect the adhesion, proliferation and differentiation of fibroblasts and osteoblasts.

The applications of ultrasound, and ultrasonography in dentistry: a scoping review of the literature

OBJECTIVES

This scoping review aims to summarize the available literature on the clinical applications of ultrasonography and ultrasound in diagnostic, therapeutic, and interventional dental applications.

MATERIALS AND METHODS

We followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses, Extension for Scoping Reviews checklist and conducted a protocol-driven scoping review of randomized controlled trials, cohort studies, cross-sectional studies, case-control studies, and case series that assessed ultrasonography or ultrasound use as a stand-alone diagnostic, therapeutic, and interventional tool in dentistry. We included studies published after 1980, study samples ≥ 10, with diagnostic, concordance, or therapeutic outcomes. We searched Ovid MEDLINE, Embase, and others (up to April 2021) and extracted information regarding study level, patient level, test or treatment level, and outcome level data.

RESULTS

Five interventional studies (related to oral medicine, temporomandibular disorders, and dental anesthesia), eight therapeutic studies (related to surgery and orthodontics), and seventy-five diagnostic studies (related to orthodontics, surgery, endodontics, oral medicine, temporomandibular disorders, restorative dentistry, and periodontology) were identified and presented in this review.

CONCLUSION

Ultrasonography has a well-established niche in diagnostic dentistry, while therapeutic and interventional ultrasounds have a smaller, yet present, niche in dentistry. However, further research is needed to report the precise estimates of the diagnostic, therapeutic, and interventional effects.

CLINICAL SIGNIFICANCE

Dentists are mostly unfamiliar with ultrasonography and ultrasound and their potential uses. This review maps the diagnostic and therapeutic applications of ultrasonography and ultrasound technology in dentistry and highlights the current challenges, gaps of knowledge, and research status of ultrasound technology in this regard.

Clinical Evaluation of a New Electronic Periodontal Probe: A Randomized Controlled Clinical Trial

Precise measurements of periodontal parameters (such as pocket depths: PPD, gingival margins: GM) are important for diagnosis of periodontal disease and its treatment. Most examiners use manual millimeter-scaled probes, dependent on adequate pressure and correct readouts. Electronic probes aim to objectify and facilitate the diagnostic process. This randomized controlled trial compared measurements of a standard manual (MP) with those of an electronic pressure-sensitive periodontal probe (EP) and its influence on patients' acceptance and practicability. In 20 patients (2436 measuring points) PPD and GM were measured either with MP or EP by professionals with different levels of experience: dentist (10 patients), 7th and 10th semester dental students (5 patients each). Time needed was measured in minutes and patients' subjective pain was evaluated by visual analogue scale. Differences were analyzed using the generalized estimating equations approach (GEE) and paired Wilcoxon tests. Mean PPD varied with ΔPPD 0.38 mm between both probes, which was significant (p < 0.001), but GM did not (ΔREC 0.07 mm, p = 0.197). There was a statistically significant correlation of both probes (Spearman's rho correlation coefficient GM: 0.674, PPD: 0.685). Differences can be considered robust (no deviation in either direction). The comparison of time needed and pain sensitivity did not result in statistically significant differences (p > 0.05).

Controlled release of iodine from cross-linked cyclodextrin metal-organic frameworks for prolonged periodontal pocket therapy

Effective therapeutic system to periodontitis was designed using cross-linked cyclodextrin metal-organic framework (COF) as carrier for iodine and further suspended in hydroxyethyl cellulose gel as I2@COF-HEC hydrogel. Inclusion of iodine within the COF was demonstrated by SR-FTIR spectral and characteristic DSC and TGA changes. Molecular modelling identified the interaction of iodine with both COF central cavity and individual cyclodextrin moieties of COF. In vitro results of study demonstrated that iodine release in artificial saliva from I2@COF-HEC hydrogel could be extended up to 5 days, which was slower than I2@COF particles. Using an in vivo rat model of periodontitis, micro-computed tomography of alveolar bone morphology demonstrated that I2@COF-HEC hydrogel showed similar effects in decreasing periodontal pocket depth and alveolar bone resorption to minocycline ointment, a periodontitis antibiotic. The I2@COF-HEC hydrogel is a novel local delivery device of iodine as a broad spectrum antimicrobial use for treatment of periodontitis.

Subgingival instrumentation for treatment of periodontitis. A systematic review

OBJECTIVES

To evaluate the efficacy of subgingival instrumentation (PICOS-1), sonic/ultrasonic/hand instruments (PICOS-2) and different subgingival instrumentation delivery protocols (PICOS-3) to treat periodontitis.

METHODS

Systematic electronic search (CENTRAL/MEDLINE/EMBASE/SCOPUS/LILACS) to March 2019 was conducted to identify randomized controlled trials (RCT) reporting on subgingival instrumentation. Duplicate screening and data extraction were performed to formulate evidence tables and meta-analysis as appropriate.

RESULTS

As only one RCT addressed the efficacy of subgingival instrumentation compared with supragingival cleaning alone (PICOS-1), baseline and final measures from 9 studies were considered. The weighted pocket depth (PD) reduction was 1.4 mm (95%CI: 1.0 1.7) at 6/8 months, and the proportion of pocket closure was estimated at 74% (95%CI: 64-85). Six RCTs compared hand and sonic/ultrasonic instruments for subgingival instrumentation (PICOS-2). No significant differences were observed between groups by follow-up time point or category of initial PD. Thirteen RCTs evaluated quadrant-wise versus full-mouth approaches (PICOS-3). No significant differences were observed between groups irrespective of time-points or initial PD. Five studies reported patient-reported outcomes, reporting no differences between groups.

CONCLUSIONS

Nonsurgical periodontal therapy by mechanical subgingival instrumentation is an efficacious means to achieve infection control in periodontitis patients irrespective of the type of instrument or mode of delivery. Prospero ID: CRD42019124887.

Peptidomic changes of saliva after nonsurgical treatment of stage I / II generalized periodontitis

OBJECTIVE

To explore the changes of peptidome profiles of saliva, serum and gingival crevicular fluid (GCF) before and after nonsurgical periodontal treatment in patients with generalized periodontitis (stage I / II).

SUBJECTS AND METHODS

Saliva, serum and GCF samples were collected from 17 patients at baseline (T₀ ), one week after ultrasonic supragingival scaling (T₁ ) and eight weeks after subgingival scaling and root planning (T₂ ). Matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS) was carried out to detect changes in peptidomic profiles. Then nano-liquid chromatography-electrospray ionization-tandem mass spectrometry (nano-LC/ESI-MS/MS) was performed to identify potential peptide biomarkers.

RESULTS

Most of the peptides from the patients exhibited a decreasing trend from the time point of pre-treatment to that of post-treatment. Cluster analysis and scatter plots using these peptides indicated that salivary peptidome has an acceptable capability of reflecting the status of stage I / II generalized periodontitis. Seven of these peptides were successfully identified as α-1-antitrypsin, immunoglobulin κ variable 4-1, haptoglobin and immunoglobulin heavy constant γ2.

CONCLUSIONS

Certain peptides in saliva, serum and GCF were down-regulated after nonsurgical periodontal treatment, demonstrating the application prospects of saliva in monitoring and surveillance of periodontal diseases in both clinical settings and communities.

[Evaluation of the effect of using ultrasonic instruments to improve the shoulder of the preparations]

OBJECTIVE

To provide the basis for the clinical development of ultrasonic shoulder preparation by comparing the roughness and three-dimensional topography of shoulder surface between ultrasonic instruments and conventional rotary instruments, to make preliminary suggestions for clinical use of ultrasonic instruments.

METHODS

(1) Four areas of buccal and palatal surfaces of six extracted human premolars were prepared with different grit size of rotary instruments. Polyether was used to take impression of the shoulder area, 3-D topography measurement laser microscope (3-D TMLM) was used to scan the impressions and compare the shoulder surface roughness of the four areas. (2) Six extracted human premolars were prepared, mesial half of the shoulder was finished with traditional rotary instruments and distal half with ultrasonic instruments. Polyether was used to take impression of the shoulder area, 3-D TMLM was used to scan the impressions and compare the shoulder surface roughness and 3-D topography, and the shoulder surface morphology was observed by surgical microscope (×25 magnification). (3) Twenty extracted human maxillary symmetrical homonymous anterior teeth were poured into die stone using artificial gingiva, ultrasonic instruments group and rotary instruments group were divided randomly. After preparing the teeth and taking the shoulder impression with polyether in dental simulate on the training system, the surface roughness of the shoulder impression in mesial, middle and distal areas was scanned and compared. The data were analyzed using SPSS 25.0 software package.

RESULTS

(1) There was no significant difference in Ra and Rz values between the abutment shoulder and impression shoulder in different areas. (2) The surface roughness of the shoulder impression prepared by ultrasonic instruments [Ra:(6.59±2.33) μm, Rz:(34.69±7.29) μm] was significantly smaller than that of the rotary instruments [Ra:(21.79±4.89) μm, Rz:(91.69±14.82) μm] (P < 0.05). The morphology of the shoulder prepared by ultrasonic instruments was clear and continuous under microscope observation. (3) The surface roughness of each area of the shoulder prepared by ultrasonic instruments was significantly lower than that of the rotary instruments (P < 0.001); there was no significant difference of the surface roughness (Ra) in each area of the shoulder impression after ultrasonic instrument preparation, while the shoulder impression roughness in the mesial and distal areas was significantly higher than that in the middle area (P < 0.001) after rotary instrument preparation.

CONCLUSION

Compared with the rotary instruments, the ultrasonic instruments can obtain a smoother shoulder surface, especially can significantly improve the shoulder preparation effect near the proximal surface.

Harnessing biomolecules for bioinspired dental biomaterials

Dental clinicians have relied for centuries on traditional dental materials (polymers, ceramics, metals, and composites) to restore oral health and function to patients. Clinical outcomes for many crucial dental therapies remain poor despite many decades of intense research on these materials. Recent attention has been paid to biomolecules as a chassis for engineered preventive, restorative, and regenerative approaches in dentistry. Indeed, biomolecules represent a uniquely versatile and precise tool to enable the design and development of bioinspired multifunctional dental materials to spur advancements in dentistry. In this review, we survey the range of biomolecules that have been used across dental biomaterials. Our particular focus is on the key biological activity imparted by each biomolecule toward prevention of dental and oral diseases as well as restoration of oral health. Additional emphasis is placed on the structure-function relationships between biomolecules and their biological activity, the unique challenges of each clinical condition, limitations of conventional therapies, and the advantages of each class of biomolecule for said challenge. Biomaterials for bone regeneration are not reviewed as numerous existing reviews on the topic have been recently published. We conclude our narrative review with an outlook on the future of biomolecules in dental biomaterials and potential avenues of innovation for biomaterial-based patient oral care.

Non-Surgical Periodontal Therapy with Adjunctive Amoxicillin/Metronidazole or Metronidazole When No Aggregatibacter actinomycetemcomitans Is Detected—A Randomized Clinical Trial

Background: The aim was to compare two different systemic antibiotics regimens adjunctive to non-surgical periodontal therapy when Aggregatibacter actinomycetemcomitans was not detected in the subgingival biofilm. Methods: A total of 58 patients with periodontitis and with no A. actinomycetemcomitans in the subgingival biofilm were treated with full-mouth subgingival instrumentation and either metronidazole (MET; n = 29) or amoxicillin/metronidazole (AMX/MET; n = 29). Probing depth (PD), clinical attachment level (CAL) and bleeding on probing (BOP) were recorded at baseline, as well as after three and six months. Subgingival biofilm and gingival crevicular fluid were collected and analyzed for major periodontopathogens and biomarkers. Results: PD, CAL and BOP improved at 3 and 6 months (each p < 0.001 vs. baseline) with no difference between the groups. Sites with initial PD ≥ 6 mm also improved in both groups after 3 and 6 months (p < 0.001) with a higher reduction of PD in the AMX/MET group (p < 0.05). T. forsythia was lower in the AMX/MET group after 3 months (p < 0.05). MMP-8 and IL-1β were without significant changes and differences between the groups. Conclusion: When A. actinomycetemcomitans was not detected in the subgingival biofilm, the adjunctive systemic use of amoxicillin/metronidazole results in better clinical and microbiological outcomes of non-surgical periodontal therapy when the application of systemic antibiotics is scheduled.

Biosafety for Dental Patients During Dentistry Care After COVID-19: A Review of the Literature

The world is currently changing due to coronavirus disease 2019 (COVID-19), and the field of dentistry is no stranger to this. The care of patients in the dental office involves very strict biosafety protocols, and patients must be aware of the protection barriers implemented to allow satisfactory, safe dental care. The purpose of this study was to synthesize and analyze the management of the current biosafety standards for dental patients since the arrival of the COVID-19 pandemic. A bibliographic search of the main sources of information including MEDLINE (by means of PubMed), Scopus, Science Direct, SCIELO, and Google Scholar was carried out. Articles published without language restriction, systematic reviews, literature reviews, and observational studies were included. We identified the biosafety measures that must be taken before, during, and after dental practice following the arrival of COVID-19. The main measures include telephone triage, temperature taking on arrival at the office, the organization of the waiting room, washing hands before entering the office, knowing the auxiliary radiographic exams of choice and what type of treatment can be performed, albeit with restrictions. In conclusion, dental patients must comply with all the biosafety measures established by international protection standards and implemented by dentists before, during, and after dental practice to reduce the possibility of COVID-19 infection.

The efficacy of pocket elimination/reduction compared to access flap surgery: A systematic review and meta-analysis

AIM

To assess the efficacy and adverse effects of resective surgery compared to access flap in patients with periodontitis.

METHODS

Randomized controlled trials with a follow-up ≥6 months were identified in ten databases. Screening, data extraction, and quality assessment were conducted by two reviewers. The primary outcome was probing pocket depth, and the main secondary outcome was clinical attachment level. Data on adverse events were collected. Meta-analysis was used to synthesize the findings of trials.

RESULTS

A total of 880 publications were identified. Fourteen publications from nine clinical trials met the inclusion criteria and were included for analysis. Meta-analysis was carried out using all available results. The results indicated superior pocket depth reduction following resective surgery compared to access flap after 6-12 months of follow-up (weighted mean difference 0.47 mm; confidence interval 0.7-0.24; p = .010). After 36-60 months of follow-up, no differences were found between the two treatments in pocket depth and attachment level. The prevalence of adverse effects was not different between the groups. Post-operative recession tended to be more severe for the resective approaches.

CONCLUSION

Resective surgical approach was superior to access flap in reducing pocket depth 6-12 months post-surgery, while no differences between the two modalities were found at 36-60 months of follow-up.

Possible aerosol transmission of COVID-19 and special precautions in dentistry

Since its emergence in December 2019, corona virus disease 2019 (COVID-19) has impacted several countries, affecting more than 90 thousand patients and making it a global public threat. The routes of transmission are direct contact, and droplet and possible aerosol transmissions. Due to the unique nature of dentistry, most dental procedures generate significant amounts of droplets and aerosols, posing potential risks of infection transmission. Understanding the significance of aerosol transmission and its implications in dentistry can facilitate the identification and correction of negligence in daily dental practice. In addition to the standard precautions, some special precautions that should be implemented during an outbreak have been raised in this review.

Profilometric Analysis of Periodontally Diseased Root Surfaces After Application of Different Instrumentation Tools: An In Vitro Study

Objective: The topography of the root surface plays an important role in plaque accumulation, cell adhesion, and periodontal healing. The aim of this study is to profilometrically evaluate the root surface changes following the instrumentation using different tools. Methods: Forty dentin blocks of buccal and lingual root surfaces were obtained from 20 single-rooted periodontally diseased hopeless teeth and randomly divided into 4 groups. Each group was subjected to different root instrumentation tools such as stainless steel (SS) Gracey curette (Group 1); titanium nitride (TIN) Gracey curette (Group 2); ultrasonic piezoelectric device with a special tip designed for root surfaces (H3) (Group 3); and Er:YAG laser (Er:YAG tip) chisel (Group 4). A calibrated clinician instrumented all surfaces in each group. The root surfaces were profilometrically evaluated before and after instrumentations. Results: There were no statistical differences between the initial roughness levels of the groups. TIN curettes revealed the most prominent effect on smoothing the surface, whereas the Er:YAG tip showed the highest roughness in comparison with the other root surface instrumentation tools. Conclusions: Considering the importance of root surface roughness after treatment for the success of periodontal therapy, the TIN curette was the most periodontally appealing tool followed by H3, SS curette, and Er:YAG tip.

Novel nanotechnology and near-infrared photodynamic therapy to kill periodontitis-related biofilm pathogens and protect the periodontium

OBJECTIVE

Periodontal tissue destruction and tooth loss are increasingly a worldwide problem as the population ages. Periodontitis is caused by bacterial infection and biofilm plaque buildup. Therefore, the objectives of this study were to: (1) develop a near-infrared light (NIR)-triggered core-shell nanostructure of upconversion nanoparticles and TiO₂ (UCNPs@TiO₂), and (2) investigate its inhibitory effects via antibacterial photodynamic therapy (aPDT) against periodontitis-related pathogens.

METHODS

The core β-NaYF₄:Yb³⁺,Tm³⁺ were synthesized via thermal decomposition and further modified with the TiO₂ shell via a hydrothermal method. The core-shell structure and the upconversion fluorescence-induced aPDT treatment via 980nm laser were studied. Three periodontitis-related pathogens Streptococcus sanguinis (S. sanguinis), Porphyromonas gingivalis (P. gingivalis) and Fusobacterium nucleatum (F. nucleatum) were investigated. The killing activity against planktonic bacteria was detected by a time-kill assay. Single species 4-day biofilms on dentin were tested by live/dead staining, colony-forming units (CFU), and metabolic activity.

RESULTS

The hexagonal shaped UCNPs@TiO₂ had an average diameter of 39.7nm. UCNPs@TiO₂ nanoparticles had positively charged (+12.4mV) surface and were biocompatible and non-cytotoxic. Under the excitation of NIR light (980nm), the core NaYF₄:Yb³⁺,Tm³⁺ UCNPs could emit intense ultraviolet (UV) light, which further triggered the aPDT function of the shell TiO₂ via energy transfer, thereby realizing the remarkable antibacterial effects against planktons and biofilms of periodontitis-associated pathogens. NIR-triggered UCNPs@TiO₂ achieved much greater reduction in biofilms than control (p<0.05). Biofilm CFU was reduced by 3-4 orders of magnitude via NIR-triggered aPDT, which is significantly greater than that of negative control and commercial aPDT control groups. The killing efficacy of UCNPs@TiO₂-based aPDT against the three species was ranked to be: S. sanguinis<F. nucleatum=P. gingivalis. Metabolic activities of biofilms were also greatly reduced via NIR-triggered aPDT (p<0.05).

SIGNIFICANCE

Upconversion fluorescence-based aPDT achieved strong inhibiting effects against all three species of periodontitis-related pathogens. This novel nanotechnology demonstrated a high promise to inhibit periodontitis, with exciting potential to combat other oral infectious diseases such as deep endodontic infections.

Methylene Blue-Mediated Photodynamic Therapy Induces Macrophage Apoptosis via ROS and Reduces Bone Resorption in Periodontitis

Aim

To investigate whether methylene blue-mediated photodynamic therapy (MB-PDT) can affect the "fate" of macrophages in vitro or in periodontitis tissues and to explore the potential mechanism.

Methods

For in vitro treatments, THP-1 macrophages were divided into three experimental groups: C/control, no treatment; MB, methylene blue treatment; and MB-PDT, MB and laser irradiation treatment. Then, apoptosis and apoptosis-related proteins were detected in each group. For in vivo treatments, periodontitis was ligature-induced in the first molars of the bilateral maxilla in 12 Sprague Dawley (SD) rats. After six weeks, the ligatures were removed and all the induced molars underwent scaling and root planning (SRP). Then, the rats were divided into three groups according to the following treatments: SRP, saline solution; MB, phenothiazinium dye; and MB-PDT, MB and laser irradiation. Apoptotic macrophages, inflammation levels, and alveolar bone resorption in the periodontal tissues of rats were analyzed in each group.

Results

In vitro, flow cytometry analysis demonstrated that 10 μM MB and 40 J/cm² laser irradiation maximized the apoptosis rate (34.74%) in macrophages. Fluorescence probe and Western blot analyses showed that MB-PDT induced macrophage apoptosis via reactive oxygen species (ROS) and the mitochondrial-dependent apoptotic pathway. Conversely, the addition of exogenous antioxidant glutathione (GSH) and the pan-caspase inhibitor Z-VAD-FMK markedly reduced the apoptotic response in macrophages. In vivo, immunohistochemistry, histology, radiographic, and molecular biology experiments revealed fewer infiltrated macrophages, less bone loss, and lower IL-1β and TNF-α levels in the MB-PDT group than in the SRP and MB groups (P < 0.05). Immunohistochemistry analysis also detected apoptotic macrophages in the MB-PDT group.

Conclusion

MB-PDT could induce macrophage apoptosis in vitro and in rats with periodontitis. This may be another way for MB-PDT to relieve periodontitis in addition to its antimicrobial effect. Meanwhile, MB-PDT induced apoptosis in THP-1 macrophages via the mitochondrial caspase pathway.

The effect of miniaturized manual versus mechanical instruments on calculus removal and root surface characteristics: An in vitro light microscopic study

Objectives

The aim of this study was to evaluate by light microscopy analysis the effect of the use of miniaturised piezoelectric tips versus mini‐five area specific curets on calculus removal and postoperative root surface alterations.

Methods

A total of 20 extracted teeth were used. Two square surfaces (5×5 mm) were marked on each root surface with a diamond bur mounted on a high‐speed handpiece. Before and after instrumentation, a series of magnified images (4.2×) of each experimental surface were taken with a standardized approach. According to a randomization list, the two surfaces on each sample were instrumented in a standardised fashion either with a mine‐five curet or a slim piezoelectric tip. The images were processed using an imaging software. Data were summarised as means and standard deviations for the two outcomes (calculus and alterations.) at each time (pre and post) for both of the groups (manual and mechanical).

Results

Both manual and mechanical instrumentation significantly reduced the calculus deposits (p < .001) without significant differences between the two groups. Both manual and mechanical treatments significantly increased alterations (p < .01). There was a statistically significant evidence of a greater increase in alterations from mechanical treatment.

Conclusions

Slim mechanical piezoelectric tips and manual mini‐five area‐specific curets have similar effects on calculus removal. Manual instrumentation results in a more homogeneous postoperative root surface with less root alterations.

Early wound healing outcomes after regenerative periodontal surgery with enamel matrix derivatives or guided tissue regeneration: a systematic review

BACKGROUND

Proper wound healing after regenerative surgical procedures is an essential issue for clinical success. Guided tissue regeneration (GTR) and application of enamel matrix derivatives (EMD) are common means to regenerate periodontal tissues. Both methods bear considerable advantages due to their special characteristics, but also go along with certain disadvantages. Today, there is no consensus in the literature whether GTR or EMD show better results regarding early wound healing, which is considered a crucial stage in periodontal regeneration. Therefore, the aim of the present systematic review was to compare the early wound healing after regenerative periodontal surgery with either EMD or GTR treatment.

METHODS

An electronic literature search in PubMed was performed to identify randomized clinical trials (RCTs) or clinical trials (CTs) comparing regenerative surgery employing EMD and/or GTR in patients with chronic periodontitis. Among the finally included studies, a qualitative and quantitative data extraction regarding early wound healing parameters was performed. Primary outcome parameters were early wound healing index (EWH), flap dehiscence, membrane exposure, suppuration and abscess formation during the first 6 weeks. As secondary parameters, swelling and allergic reactions were assessed.

RESULTS

Seven studies reporting 220 intrabony periodontal defects in 199 patients were analysed. Flap dehiscence was observed in two studies in 12% of the GTR treated sites and in 10.3% of those treated with EMD. Membrane exposure was evaluated in five studies and was registered in the 28.8% of the defects, while no dehiscence was reported on the EMD group. Swelling was reported only in one study in 8/16 GTR sites and 7/16 EMD sites. Due to considerable heterogeneity of parameters no meta-analysis was possible.

CONCLUSIONS

Due to considerable heterogeneity of the published studies a clear beneficial effect of the EMD on the early wound healing outcomes after surgical treatment of periodontal intrabony defects cannot be confirmed. Standardized RCT studies are needed in order to allow for proper comparison of early wound healing after both types of surgical approaches.

Periodontitis: facts, fallacies and the future

This volume of Periodontology 2000 represents the 25th anniversary of the Journal, and uses the occasion to assess important advancements in periodontology over the past quarter-century as well as the hurdles that remain. Periodontitis is defined by pathologic loss of the periodontal ligament and alveolar bone. The disease involves complex dynamic interactions among active herpesviruses, specific bacterial pathogens and destructive immune responses. Periodontal diagnostics is currently based on clinical rather than etiologic criteria, and provides limited therapeutic guidance. Periodontal causative treatment consists of scaling, antiseptic rinses and occasionally systemic antibiotics, and surgical intervention has been de-emphasized, except perhaps for the most advanced types of periodontitis. Plastic surgical therapy includes soft-tissue grafting to cover exposed root surfaces and bone grafting to provide support for implants. Dental implants are used to replace severely diseased or missing teeth, but implant overuse is of concern. The utility of laser treatment for periodontitis remains unresolved. Host modulation and risk-factor modification therapies may benefit select patient groups. Patient self-care is a critical part of periodontal health care, and twice-weekly oral rinsing with 0.10-0.25% sodium hypochlorite constitutes a valuable adjunct to conventional anti-plaque and anti-gingivitis treatments. A link between periodontal herpesviruses and systemic diseases is a strong biological plausibility. In summary, research during the past 25 years has significantly changed our concepts of periodontitis pathobiology and has produced more-effective and less-costly therapeutic options.

Nonsurgical and surgical treatment of periodontitis: how many options for one disease?

Treatment of periodontitis aims at preventing further disease progression with the intentions to reduce the risk of tooth loss, minimize symptoms and perception of the disease, possibly restore lost periodontal tissue and provide information on maintaining a healthy periodontium. Therapeutic intervention includes introduction of techniques to change behavior, such as: individually tailored oral-hygiene instructions; a smoking-cessation program; dietary adjustment; subgingival instrumentation to remove plaque and calculus; local and systemic pharmacotherapy; and various types of surgery. No single treatment option has shown superiority, and virtually all types of mechanical periodontal treatment benefit from adjunctive antimicrobial chemotherapy. Periodontal treatment, because of the chronic nature of periodontitis, is a lifelong commitment to intricate oral-hygiene techniques, which, when properly implemented, will minimize the risk of disease initiation and progression.

Comparative evaluation of manual scaling and root planing with or without magnification loupes using scanning electron microscope: A pilot study

Aim:

The aim of the present study is to compare the amount of remaining calculus, loss of tooth substance, and roughness of root surface after scaling and root planing with or without magnification loupes using scanning electron microscope.

Materials and Methods:

In the study, 30 teeth indicated for extractions due to severe chronic generalized periodontitis were included in the study. In test Group I, scaling and root planing was performed without magnification loupes, and in test Group II, scaling and root planing was performed with magnification loupes before extraction. In control Group III, no procedure was performed. After scaling and root planing, teeth were extracted followed by preparation of specimens. Specimens were then sent for scanning electron microscope study.

Results:

Statistically significant (P ≤ 0.05) differences were found among different test groups. Results showed that test Group II with magnification loupes had less remaining calculus and smoother surface with lesser amount of loss of cementum layer.

Conclusion:

From this, it was concluded that test Group II was more efficient in root debridement than test Group 1, so scaling and root planing done with magnification loupes will cause less damage to the tooth surface.

Local application of statins in the treatment of experimental periodontal disease in rats

Objective

The objective of this study was to evaluate the local effects of statins as adjuvants for treatment by scaling and root planing (SRP) of periodontal disease induced in rats.

Material and Methods

Ninety rats were used in the present experiment. Periodontal disease was induced in all animals using a cotton thread placed in the left first mandibular molar. After 7 days of induction, the bandage was removed and the animals were divided into three groups: 1) NT group (n=30), no treatment; 2) SRP group (n=30): SRP and irrigation with control gel; 3) S group (n=30) - SRP and irrigation with Simvastatin. Ten animals from each group were euthanized at 7, 15 and 30 days after treatment. Gingival biopsy specimens were processed to analyze the expression of matrix metalloproteinase 8 (MMP-8). The mandibles were removed and submitted to radiographic and laboratory processing for histometric analysis.

Results

The S group showed a significantly lower expression of MMP-8 compared to NT and SRP groups in all experimental periods. In the radiographic and histometric analyses between the groups, S group showed a significantly lower bone loss (BL) compared to NT and SRP groups in all experimental periods.

Conclusions

Within the limits of this study, it can be concluded that locally applied statin was effective as an adjuvant treatment for SRP in rats with induced periodontal disease.

Minimally invasive periodontal therapy for general practitioners

There remains a high prevalence of mild-to-moderate forms of periodontal diseases in both developed and developing countries. Although many periodontal specialty practices currently place strong emphasis on implant surgery, periodontal plastic surgery and esthetics, general dentists and hygienists have often assumed more responsibility than periodontal specialty practices for the diagnosis, treatment, assessment and maintenance, and possible referral, of their patients. To address these current trends and challenges, this volume of Periodontology 2000 presents a series of topics on the basic biological principles of periodontal disease, as well as on approaches to diagnosis, treatment planning and treatment, in what is called 'conservative' or 'noninvasive' periodontal therapy. These topics include risk assessment of the periodontal condition; reduction, elimination and/or control of etiologies and risk factors, including mechanical, antimicrobial and host-modulation approaches; considerations for evaluation of clinical outcomes based on treatment approaches; and selected topics in laser therapy, halitosis and gingival recession.