Biological action of bleaching agents on tooth structure: A review.

The use of bleaching agents to remove stains is one of the main dental procedures to improve the aesthetics of teeth. This review presents the main agents used for tooth whitening, existing clinical protocols, and the structural changes that may occur through their use. The main bleaching agents consist of hydrogen peroxide and carbamide peroxide, which are used in bleaching techniques for vital teeth. These techniques can be performed in the office by a professional or by the individual in a home en-vironment under professional guidance. Bleaching agents come in a variety of concentrations and there are over-the-counter products available on the market with lower concentrations of hydrogen peroxide. Due to the chemical characteristics of the agents, changes in the organic and inorganic content of the tooth structure can be observed. These changes are related to morphological changes characterized by in-creased permeability and surface roughness, such changes compromise the mechanical resistance of the tooth. Furthermore, bleaching agents can promote molecular changes after reaching the dental pulp, resulting in oxidative stress of pulp cells and the release of pro-inflammatory mediators. Despite the bleaching effectiveness, tooth sensitivity is considered the main side effect of use. Therefore, among the heterogeneity of protocols, those that used the bleaching agent for a prolonged time and in lower con-centrations presented more harmful effects on the tooth structure.

Influence of blue and violet LED and infrared laser on the temperature of bleaching protocols in different concentrations of hydrogen peroxide.

BACKGROUND: The photo-acceleration of bleaching gels by lights has been extensively researched. However, the induced temperature increase during this process needs to be further evaluated to prevent damage to the dental pulp. Therefore, the objective of this study was to evaluate the surface and intrapulpal temperature kinetics of different concentrations of hydrogen peroxide (HP) gels photo-accelerated by blue or violet light and infrared laser. METHODS: The whitening gels at concentrations of HP35, HP15, and HP6 % were irradiated with blue and violet LED/laser on the surface of a human canine tooth. The surface temperature variation (∆Ts) was evaluated using a pH meter, while the intrapulpal temperature variation (∆Ti) was assessed using a digital thermometer at intervals of 1, 15, and 30 min. Statistical analysis was conducted using a Two-way repeated measures ANOVA test, and Bonferroni post-test was applied at a significance level of 5 %. RESULTS: All violet LED photo-accelerated groups showed a higher increase in ∆Ts compared to the blue LED/laser groups. However, there were no significant differences between the groups for ∆Ti. CONCLUSION: Although the photo-acceleration of HP35 and HP15 % gels with violet LED/laser has a greater increase in surface temperature compared to HP6 % gel, the different light systems do not significantly increase the intrapulpal temperature.

A randomized clinical study of the performance of self-etching adhesives containing HEMA and 10-MDP on non-carious cervical lesions: A 2-year follow-up study.

OBJECTIVE: To evaluate the association of HEMA and 10-MDP in the clinical performance of self-etching adhesives in the restoration of NCCLs during 2-years. MATERIALS AND METHODS: 60 restorations were performed in 17 volunteers and randomized into three groups: G1 (n = 20) - Prime and Bond Universal (10-MDP); G2 (n = 20) - Optibond All-in-One (HEMA); and G3 (n = 20) - Clearfil SE (10-MDP and HEMA). No cavity preparation was performed. After 2 years, the restorations were evaluated using the modified USPHS criteria for retention, marginal adaptation/ staining, postoperative sensitivity and secondary caries. The results were analyzed using Fisher's exact test and Kruskal-Wallis test. RESULTS: All groups showed 100% retention rate, except G1, who lost two restorations (p > 0.05). Regarding marginal adaptation, G1 showed greater deficiency, as only eight restorations (40%) remained intact (p < 0.05). Regarding marginal staining, G1 and G2 showed higher rate, as only 12 restorations (65%) in each one were free of staining (p < 0.05). All groups showed similar results for postoperative sensitivity and secondary caries (p > 0.05). CONCLUSION: The association of HEMA and 10-MDP monomers in the self-etching adhesives did not influence the clinical performance of the NCCL restorations with respect to retention, postoperative sensitivity, and incidence of secondary caries. However, positively influenced the marginal adaptation and marginal staining at the 2-year follow-up. CLINICAL SIGNIFICANCE: The association of HEMA and 10-MDP monomers in the self-etching adhesives positively influence the clinical performance of the NCCL restorations with respect to marginal adaptation and marginal staining.

Influence of smoking on the effectiveness of tooth whitening: a systematic review.

OBJECTIVES: Perform a systematic review to evaluate the influence of smoking on the effectiveness of tooth whitening (TW) and to analyze whether tooth sensitivity is different between smokers and non-smokers. MATERIALS AND METHODS: A systematic review modeled according to the PRISMA guidelines was conducted. PubMed, Embase, Web of Science, Cochrane, Scopus, and OpenGrey databases were searched for related clinical trials. The population, exposure, comparison, outcomes (PECO) was individuals who had TW performed, smoking individuals, non-smoking individuals, and effectiveness of TW, respectively. Risk of bias was assessed with the ROBINS-I tool, and data from included studies were extracted by two researchers independently. The certainty of the evidence was evaluated using the GRADE (Grading of Recommendations, Assessment, Development, and Evaluations) approach. RESULTS: Five studies were selected for qualitative analysis. The ROBINS-I tool classified 3 studies as having a moderate risk of bias, one study as having a serious risk of bias, and one with a critical risk. GRADE performed only for color change results and showed a low certainty of evidence. Limited evidence suggests that effectiveness of TW between smokers and non-smokers is similar. The tooth sensitivity also does not seem to be influenced by smoking. Due to the heterogeneity of the data, a meta-analysis could not be performed. CONCLUSIONS: Effectiveness of TW between smokers and non-smokers is comparable. The tooth sensitivity also does not seem to be influenced by smoking. CLINICAL RELEVANCE: The effectiveness of bleaching among smokers and non-smokers appears to be similar. Tooth sensitivity during TW also appears not to be influenced by smoking.

Effect of 1.5% potassium oxalate on sensitivity control, color change, and quality of life after at-home tooth whitening: A randomized, placebo-controlled clinical trial.

OBJECTIVE: This clinical trial evaluated the effect of 1.5% potassium oxalate (PO) in controlling sensitivity and color change after at-home tooth whitening. It also evaluated the influence of PO on health-related quality of life (HRQoL) and the degree of patient satisfaction after bleaching treatment. MATERIALS AND METHODS: Fifty volunteers were randomized into two groups (n = 25): At-home bleaching gel with 22% carbamide peroxide for 45 min + placebo gel (GP) or 1.5% PO (GPO) for 10 min. The intensity of tooth sensitivity was assessed daily through the visual analog scale. The color analysis was performed three times: baseline, 21 days, and 1 month after the last application of the whitening gel. The impact of the oral condition on the patient's quality of life (OIDP) was used to measure the impact caused by the whitening treatment in relation to the individuals' ability to carry out their daily activities and its influence on HRQOL. RESULTS: No difference in tooth sensitivity was observed (p > 0.05). In addition, there was no difference in color change between groups (p > 0.05). However, there was an intragroup statistical difference throughout the evaluation period (p <0.05). The OIDP analysis showed a statistical difference between the groups (p > 0.05) and there was no difference between the groups regarding the degree of satisfaction with the bleaching (p > 0.05). CONCLUSIONS: The 1.5% PO was effective in preventing sensitivity and did not interfere with tooth whitening. Desensitizing therapy had a positive impact on quality of life and patient satisfaction.

The effect of photobiomodulation using low-level laser therapy on tooth sensitivity after dental bleaching: a systematic review.

The authors aimed to conduct a systematic review to assess data from the current literature on the effectiveness of low-level laser therapy (LLLT) in preventing tooth sensitivity (TS) after tooth whitening (DB). PRISMA guidelines for systematic reviews were followed. Clinical trials evaluating the treatment of LLLT in patients with sensitivity after tooth whitening were selected. A full bibliographic search was performed on May 4, 2021, in the following databases: Embase, MEDLINE via PubMed, SciELO, VHL Regional Portal, Web of Science, Gray Literature, Scopus, ClinicalTrials.gov and Cochrane Library. This study followed Cochrane's recommendations for analyzing risk of bias. A total of 1054 studies were found (255 studies were excluded because they were duplicates and 785 because of titles and abstracts). Only 14 articles were selected for analysis, of which eight were excluded because they had one or more exclusion criteria, resulting in six articles included in this systematic review, the vast majority being classified as low risk of bias. The studies reviewed indicated that LLLT showed promise in preventing TS after TB. However, evidence is limited and more clinical trials with low risk of bias are needed to reach a definitive conclusion on the action of LLLT in pain control after TB.

Combination of two desensitizing protocols to control dentin hypersensitivity in non-carious lesions: a randomized, double-blind clinical trial.

OBJECTIVES: This study evaluated the effect of photobiomodulation (PBM) combined with 8% strontium acetate (SA8%) in the treatment of dentin hypersensitivity (DH) in non-carious lesions and analyzed the risk factors with the patient's quality of life. METHODS: Eighty teeth with DH were randomly allocated into four treatment groups (n = 20): G1, PBM imitation + toothpaste with no active ingredient; G2, PBM imitation + toothpaste with SA8%; G3, PBM + toothpaste without the active ingredient; and G4, PBM + toothpaste with SA8%. Participants were provided with a questionnaire on the experience of dentin hypersensitivity (QEDH) to assess the impact of desensitizing treatment on health-related quality of life (HRQL). Friedman and Kruskal-Wallis tests were used for intra- and intergroup comparisons, and Wilcoxon and Mann-Whitney tests were used to analyze HRQL. All analyses used significance levels of 5%. RESULTS: Intergroup comparisons revealed a significant difference (p < 0.05); G4 had the best response in terms of HD reduction in G4 compared to the other groups on the 7th day of assessment (T3). Only G4 showed a statistically significant difference (p < 0.05) in the reduction of EDH for intragroup analysis. CONCLUSION: The combination of therapies was more effective in reducing DH than the isolated use of these strategies. CLINICAL RELEVANCE: The combination of therapies is effective in the treatment of DH.

Factors associated with depression, anxiety and stress among dentists during the COVID-19 pandemic.

The objective of this work was to evaluate the relationship between factors associated with the COVID-19 pandemic and depression, anxiety, and stress (DAS) in dentists. Factors associated with the COVID-19 pandemic were evaluated using a questionnaire and scores of the Depression, Anxiety, and Stress Scales-21 were measured. The differences between the DAS scores based on the factors associated with the COVID-19 pandemic were tested through the successive application of multivariate analysis of variance (MANOVA, α = 0.05). After a sample size calculation, 998 participants with a mean age of 39.39 (± 11.69) years were included. The effect size indicated that changes in sleep quality (η2 = 0.161), eating habits (η2 = 0.057), and physical health (η2 = 0.051) were the ones that most negatively affected DAS scores. The highest DAS scores were observed in professionals who lived with someone at high-risk for COVID-19 (p < 0.001) and in those who did not engage in leisure activities during the pandemic (p < 0.001). Dentists who worked on the frontline against COVID-19 had higher scores of anxiety and stress (p = 0.029). The highest scores for anxiety, depression, and/or stress were seen in dentists living with someone at high-risk for COVID-19, who acts on the frontline, who does not practice in leisure activities during the pandemic, who completely changed eating habits, quality of sleep and physical health during the pandemic. In general, DAS levels of dentists were associated with factors related to the COVID-19 pandemic.

COMPLIANCE OF RANDOMIZED CLINICAL TRIALS ON DENTAL CARIES PREVENTION METHODS WITH THE CONSORT STATEMENT: A SYSTEMATIC REVIEW.

OBJECTIVE: Reporting of randomized controlled trials (RCTs) in dentistry remains suboptimal. Considering the positive impact of the Consolidated Standards of Reporting Trials (CONSORT) guidelines on the quality of evidence in RCTs, the main objective of this systematic review was to determine whether RCTs on dental caries prevention conform to these guidelines. The secondary objective was to assess the association between CONSORT adherence and the year and impact factor of the journal in which the study was published. METHODS: A systematic search was conducted in different databases using appropriate terms to retrieve RCTs that assessed the caries-preventive effect of at least 2 of the following materials-fluoride varnish, resin-based fissure sealants, and ionomer-based fissure sealants-on the occlusal surfaces of permanent molars. Since the first CONSORT statement was published in 1996, a time frame from 1997 to 2020 was established for the identification of studies. Selected articles were assessed according to their adherence to the CONSORT statement, risk of bias (Cochrane risk of bias tool, RoB 2.0), and journal impact factor based on the InCites Journal Citation Reports. The year of publication and other relevant data were also recorded. SPSS (SPSS Statistics 25.0, IBM©) was used to perform the linear correlation analyses to determine the relationship between the article CONSORT score (previously determined) and the year of publication and journal impact factor. A significance level of 5% was established for all analyses. RESULTS: Of 3196 references retrieved, 30 articles were selected and evaluated. Using RoB 2.0, 8 studies were classified as having a high risk of bias, 16 as having some concerns about the risk of bias assessment, and 6 as having a low risk of bias. Concerning CONSORT adherence, 77% of the studies adequately reported the intervention domain, since the methodology for the application of fluoride varnish or sealant materials was thoroughly described. However, the participants' setting and location, random sequence generation, randomization, and the flowchart description of the losses/exclusions domains were poorly reported. Meanwhile, the allocation concealment process was not reported in 83% of the articles. Correlation analyses indicated a positive relationship between CONSORT adherence and the year of publication, as well as the journal impact factor. CONCLUSION: When assessing clinical trials on the prevention of occlusal caries, most RCTs examined followed the CONSORT statement. However, some methodological domains remain poorly reported, demonstrating the need to improve CONSORT compliance in these RCTs.

Combination of strontium chloride and photobiomodulation in the control of tooth sensitivity post-bleaching: A split-mouth randomized clinical trial.

OBJECTIVE: This split-mouth randomized controlled clinical trial assessed the effect of 10% strontium chloride in combination with photobiomodulation (PBM) for the control of tooth sensitivity (TS) post-bleaching. METHODS: The upper/lower, right and left quadrants of fifty volunteers were randomized and allocated to four groups (n = 25): PLACEBO-placebo gel + simulation of PBM; Placebo + PBM; STRONTIUM-10% strontium chloride + simulation of PBM; and PBM + STRONTIUM-10% strontium chloride + PBM. All groups received tooth bleaching treatment with 35% hydrogen peroxide. For the PBM treatment, the laser tip was positioned in the apical and cervical regions of the teeth bleached in the respective hemi-arch. The laser system was operated in continuous mode, using 1.7 J of energy. A dose of 60 J/cm2 was applied to each point for 16 seconds under 808 nm near-infrared light (100mW of power), with a point area of 0.028 cm2. TS was assessed during a 21-day follow-up, using the modified visual analogue scale. RESULTS: In the intragroup assessment, the Friedman test indicated that PBM + STRONTIUM promoted the greatest reduction in TS after the second week of treatment (p ≤ 0.05). The Wilcoxon-Mann-Whitney test indicated that the groups Placebo + PBM, STRONTIUM, and STRONTIUM + PBM did not differ statistically (p ≥ 0.05) in the first and third weeks of treatment The group PLACEBO exhibited the greatest TS in the first three days after each bleaching session. CONCLUSION: The combination of 10% strontium chloride with PBM was effective in reducing post-bleaching TS; however, the combination of 10% strontium chloride with PBM was effective in reducing post-bleaching TS; however, it did not differ from the individual use of Placebo + PBM or STRONTIUM groups assessed after 21 days of follow-up.

Molars Fracture Resistance with Class II Cavities Restored with Different Resin - Based Materials / Resistência à Fratura de Molares com Cavidades Classe II Restauradas com Diferentes Materiais à Base de Resina

The teeth weakening due to the preparation of class II mesio-occluso-distal cavities is a challenge for the clinician. The objective of this study was to evaluate the molars fracture resistance with class II mesio-occluso distal cavities restored with different restorative techniques and materials. Forty extracted molars were divided into 5 groups: Group 1 ­ intact healthy teeth (positive control); Group 2 ­ unrestored teeth with mesio-occluso distal class II cavities (negative control); Groups 3 to 5 ­ restored teeth with standardized dimensions. In groups 3 to 5, the cavities were restored with flow resin only, flow resin coated with a nano-hybrid resin, and nano-hybrid resin only, respectively. All specimens were tested for resistance to fracture using an axial compressive load, a metallic sphere measuring 8 mm in diameter on a universal testing machine EMIC DL-2000. A 10 kN load cell operated at a speed of 5 mm/min until the tooth fracture. Data were subjected to analysis of variance and Tukey's tests (α = 0.05). Group 3 showed higher fracture strength (2243.1 ± 473.7N) when compared to groups 2, 4 and 5. This difference was statistically significant (p<0.05). The fracture strength of teeth restored with flow mesio occluso-distal restorations was similar to that of intact natural teeth. (AU)

O enfraquecimento dos dentes devido às preparações de cavidades mesio-ocluso-distal é um desafio para o clínico. O objetivo deste estudo foi avaliar a resistência à fratura de molares com cavidades mesio-ocluso-distais classe II restauradas com diferentes técnicas e materiais restauradores. Quarenta molares extraídos foram divididos em 5 grupos: Grupo 1 ­ dentes saudáveis intactos (controle positivo); Grupo 2 ­ dentes não restaurados com cavidades mesio-occluso-distais classe II (controle negativo); Grupos 3 a 5 ­ dentes restaurados com dimensões padronizadas. Nos grupos 3 a 5, as cavidades foram restauradas apenas com resina flow, resina flow recoberta com uma resina nanohíbrida e somente resina nano-híbrida, respectivamente. Todas as amostras foram testadas quanto à resistência à fratura usando uma carga compressiva axial, usando uma esfera metálica medindo 8 mm de diâmetro em uma máquina de teste universal EMIC DL-2000. Uma célula de carga de 10 kN operava a uma velocidade de 5 mm/min até a fratura do dente. Os dados foram submetidos à análise de variância e testes de Tukey (α = 0,05). O grupo 3 apresentou maior resistência à fratura (2243,1 ± 473,7N) quando comparado aos grupos 2, 4 e 5. Essa diferença foi estatisticamente significante (p <0,05). A resistência à fratura dos dentes restaurados com resina flow foi semelhante à dos dentes naturais intactos. (AU)

Factors associated with depression, anxiety and stress among dentists during the COVID-19 pandemic

Abstract The objective of this work was to evaluate the relationship between factors associated with the COVID-19 pandemic and depression, anxiety, and stress (DAS) in dentists. Factors associated with the COVID-19 pandemic were evaluated using a questionnaire and scores of the Depression, Anxiety, and Stress Scales-21 were measured. The differences between the DAS scores based on the factors associated with the COVID-19 pandemic were tested through the successive application of multivariate analysis of variance (MANOVA, α = 0.05). After a sample size calculation, 998 participants with a mean age of 39.39 (± 11.69) years were included. The effect size indicated that changes in sleep quality (η2 = 0.161), eating habits (η2 = 0.057), and physical health (η2 = 0.051) were the ones that most negatively affected DAS scores. The highest DAS scores were observed in professionals who lived with someone at high-risk for COVID-19 (p < 0.001) and in those who did not engage in leisure activities during the pandemic (p < 0.001). Dentists who worked on the frontline against COVID-19 had higher scores of anxiety and stress (p = 0.029). The highest scores for anxiety, depression, and/or stress were seen in dentists living with someone at high-risk for COVID-19, who acts on the frontline, who does not practice in leisure activities during the pandemic, who completely changed eating habits, quality of sleep and physical health during the pandemic. In general, DAS levels of dentists were associated with factors related to the COVID-19 pandemic.

Effect of desensitizing agents on dentin hypersensitivity after non-surgical periodontal therapy: A systematic review and meta-analysis.

OBJECTIVE: To investigate the effectiveness of desensitizing agents (DA) on dentin hypersensitivity (DH) after non-surgical periodontal treatment (NSPT) through a systematic review and meta-analysis. DATA: The PICO strategy was used to include randomized clinical trials in human subjects with DH (P) after NSPT treated with DA (I) compared to those treated with placebo or control (C) to identify DH relief (O). The Cochrane guidelines and GRADE was used to classify the risk of bias and the quality of the evidence, respectively. SOURCES: PubMed, Web of Science, Scopus, Lilacs, Cochrane Library databases, and OpenGrey were searched on the 20th of May 2020. STUDY SELECTION: Nine studies were included in the quantitative synthesis. Five meta-analyses were performed. Three meta-analyzes assessed the effectiveness of DA compared to a placebo or control in relation to pain assessment stimuli and two meta-analyzes assessed the mechanism of action of DA. For the mechanical stimulus in overall analysis, the control group presented a higher mean of pain reduction (SMD 1.03 [0.73, 1.32], p < 0.001) with very low certainty of evidence. For water (SMD -0.78 [-1.22, -0.35], p = 0.0009) and evaporative in overall analysis (SMD -1.21 [-1.79, -0.64], p < 0.001) stimuli, the DA decreased DH pain with very low and low certainty of evidence, respectively. CONCLUSION: Due to the limited quality of evidence, there is no definitive conclusion on the effectiveness of DA on DH after NSPT. Thus, further clinical studies with a low risk of bias and high-quality evidence are encouraged to reinforce the certainty of evidence on that issue. CLINICAL SIGNIFICANCE: The use of desensitizing agents show promise for relief of dentin hypersensitivity after non-surgical periodontal therapy.

Accuracy of near-infrared light transillumination (NILT) compared to bitewing radiograph for detection of interproximal caries in the permanent dentition: A systematic review and meta-analysis.

OBJECTIVE: To evaluate the accuracy of the near-infrared light transillumination (NILT) for the detection of interproximal dental caries in permanent dentition when compared to bitewing X-ray (BW). DATA: In vivo studies that detected interproximal primary caries in permanent teeth by using NILT and BW were selected. QUADAS-2 was used to assess the risk of bias. Pooled sensitivity and specificity forest plots were calculated, summary receiver operator characteristics (SROC) curves were constructed. The certainty of the evidence was rated using the GRADE system. SOURCES: Pubmed, Cochrane Library, Web of Science, Scopus, Lilacs/BBO and grey literature databases were surveyed. STUDY SELECTION: From 1594 retrieved articles, 13 studies were included. Six studies had a low risk of bias and a low level of concern regarding applicability. Four studies had an unclear risk of bias, while three presented a high risk of bias. The meta-analysis of six studies demonstrated that NILT presented good overall accuracy. Of 6110 teeth, 92.3 % (5639) were accurately classified (776 as true positive and 4863 as true negative). The pooled sensitivity was 0.97 (0.96 to 0.98; p = 0.0000; I2 = 93.2 %) with moderate certainty of evidence, and the pooled specificity was 0.91 (0.91 to 0.92; p = 0.0000; I2 = 98.3 %) with high certainty of evidence. Symmetric (0.9837) and asymmetric (0.9836) SROC showed a high discrimination and determination effect of NILT. CONCLUSION: The current literature, with moderate certainty and a middling quality of evidence, demonstrates that NILT presents a reasonably comparable accuracy to that of BW for detecting interproximal carious lesions in the permanent dentition. CLINICAL SIGNIFICANCE: Since NILT presented good overall accuracy for the detection of interproximal primary caries, it could be routinely used in dental check-ups, especially in high-risk caries populations and in patients where the use of radiation should be reduced, like pregnant women or children.

Morphological and chemical effects of in-office and at-home desensitising agents containing sodium fluoride on eroded root dentin.

OBJECTIVE: The aim of this study was to evaluate the morphological and chemical effect of in-office and at-home desensitising agents containing sodium fluoride (NaF) on eroded root dentine in vitro. METHODS: Fifty bovine dentine samples were pre-eroded and randomised into five groups (n = 10): G1 (Control) - milli-Q water; G2 - fluoride varnish containing NaF 22,500 ppm; G3 - desensitising cream containing NaF 9,000 ppm associated with 20% nanohydroxyapatite; G4 - toothpaste with NaF 5,000 ppm associated to tricalcium phosphate; G5 - toothpaste containing NaF 900 ppm and casein phosphopeptide-amorphous calcium phosphate fluoride (CPP-ACPF). The specimens were submitted to erosive challenge for three days. The analyses were performed using non-contact profilometry for volumetric (Sa) and linear roughness (Ra) followed by scanning electron microscopy (SEM) and Energy Dispersive X-ray Spectrometry (EDS). The data were analysed by Kruskal-Wallis and Wilcoxon tests (α = 0.05). RESULTS: There was a significant reduction of Ra and Sa for the eroded samples from the G2 and G5 (p < 0.05) after an erosive challenge. The dentine surface topography pattern showed partially or totally occluded dentinal tubules after treatments, except in the control group. The control, G4 and G3 groups showed a reduction in the dentine inorganic content percentage of Ca (Calcium) and P (Phosphorus) minerals. CONCLUSION: The fluoride varnish and CPP-ACPF toothpaste were able to prevent morphological changes and were the only materials that showed the Ca and P content increased after treatment. These materials may be promising alternatives in the clinical control of dentin erosion.

Evaluation of physical-mechanical properties of self-adhesive versus conventional resin cements

Aim: The purpose of this study was to compare the microhardness, diametral tensile strength, compressive strength and the rheological properties of self-adhesive versus conventional resin cements. Methods: Specimens of a conventional (RelyX ARC) and 3 self-adhesive (RelyX U200, Maxcem Elite, Bifix SE) types of resin cements were prepared. The Knoop test was used to assess the microhardness, using a Microhardness Tester FM 700. For the diametral tensile strength test, a tensile strength was applied at a speed of 0.6 mm/minute. A universal testing machine was used for the analysis of compressive strength and a thermo-controlled oscillating rheometer was used for the Rheology test. One-way ANOVA and Tukey's test (α=0.05) were used for data analysis. Results:According to microhardness analysis, all the cements were statistically similar (p>0.05), except for Maxcem that presented lower hardness compared with the other cements in relation to the top surface (p<0.05). In the diametral tensile strength test, Relyx U200 and RelyX ARC cements were statistically similar (p>0.05), presented higher value when compared to the Maxcem and Bifix cements (p<0.05). The compressive strength of RelyX ARC and Maxcem Elite cements was statistically higher than RelyX U200 and Bifix cements (p<0.05). Regarding the rheology test, Maxcem Elite and RelyX ARC cements showed a high modulus of elasticity. Conclusions: The self-adhesive cements presented poorer mechanical properties than conventional resin cement. Chemical structure and types of monomers employed interfere directly in the mechanical properties of resin cements

Effect of the casein phosphopeptide-amorphous calcium phosphate fluoride (CPP-ACPF) and photobiomodulation (PBM) on dental hypersensitivity: A randomized controlled clinical trial.

OBJECTIVE: This randomized controlled clinical trial aimed to evaluate the effect of the casein phosphopeptide-amorphous calcium phosphate fluoride (CPP-ACPF) and photobiomodulation (PBM) in the treatment of dentin hypersensitivity (DH), and the impact of this on the health-related quality of life (HRQL). METHODS: Eighty teeth with DH were randomized into four groups and received three treatment sessions: PLACEBO = placebo + LASER application mimicking; CPP-ACPF = CPP-ACPF + LASER application mimicking; PBM = placebo + LASER active application; CPP-ACPF+PBM = CPP-ACPF + LASER active application. Tactile (exploratory probe) and evaporative (triple syringe) stimuli were used to measure DH and were recorded with the aid of a visual analogue scale (VAS) after the 1st, 2nd and 3rd treatment sessions and one-month follow-up. The HRQL was recorded in the DH experience questionnaire (DHEQ). RESULTS: The intragroup comparison showed a significant reduction in DH (p < 0.05) with both stimuli after one-month follow-up. The intergroup comparison with the evaporative stimulus showed that CPP-ACPF+PBM significantly reduced DH when compared to the rest of treatments, after one-month follow-up. CPP-ACPF+PBM group statistically differed from the other treatment groups in the DHEQ evaluation after one-month follow-up. CONCLUSION: After one-month follow-up, the association of CPP-ACPF with PBM was effective in the reduction of DH and promoted a positive impact on the HRQL of the participants of this study.

Effect of low-level laser therapy combined with 5000 parts per million fluoride dentifrice on postbleaching sensitivity: A clinical, randomized, and double-blind study.

OBJECTIVE: The aim of this double-blind, randomized, controlled clinical study was to assess the efficacy of low-level laser therapy (LLLT) combined with 5000 ppm fluoride dentifrice on postbleaching sensitivity in teeth exposed to 35% hydrogen peroxide for four weeks. MATERIALS AND METHODS: Twenty-five volunteers were evaluated using the split-mouth model in which the right and left maxillary/mandibular quadrants were randomized and allocated to one of two groups: GPLACEBO, in which the laser tip was positioned without the emission of light (placebo effect) + 5000 ppm sodium fluoride, or GLASER, which comprised LLLT + 5000 ppm sodium fluoride. For both groups, LLLT and placebo were used before bleaching, whereas fluoride was applied after bleaching. LLLT was applied at two points: on the central cervical and medial regions of the incisors, canines, and premolars in the corresponding hemi-arch. At each point, 60 J/cm2 was applied for 16 seconds with an irradiance of 3.75 W/cm2 using the therapeutic infrared device. To assess tooth sensitivity, a modified visual analogue scale was used after an evaporative stimulus, and a daily pain questionnaire was also applied. RESULTS: The Wilcoxon and Friedman tests demonstrated a significant difference in the incidence of sensitivity pain between GPLACEBO and GLASER (P ≤ .05), with different evaluation times. CONCLUSION: Teeth treated with laser therapy in combination with the topical use of sodium fluoride at each bleaching session demonstrated less sensitivity compared with the application of sodium fluoride only. CLINICAL SIGNIFICANCE: The use of a low-level laser therapy in combination with topical use of sodium fluoride improves symptoms of dentin sensitivity at each bleaching session.

Effect of high concentrated fluoride-based dentifrice on the hardness, roughness, and color of the bleached enamel.

CONTEXT: Remineralizing agents have been recommended to restore the integrity of bleached enamel. AIMS: The aim of this study was to evaluate the effect of fluoride at high concentration (5000 ppm) applied to bleached enamel. MATERIALS AND METHODS: A total of 30 specimens obtained from newly extracted third molars were divided into two groups (n = 15) as follows: control group and fluoride group. Specimens of both groups received bleaching treatment with 35% hydrogen peroxide, were then submitted to the Vickers hardness number/colorimetric test (VHN/CT) (n = 5) and Ra (n = 10) tests, and stored in artificial saliva. After bleaching, fluoride group received the application of a fluoride-based dentifrice, during 5 min. VHN, RS, and CT analysis of both groups were performed before and after treatments. For VHN, five indentations per specimen were performed, using a microdurometer. Ra analysis was performed with a rugosimeter. The color was analyzed through the CIE L* a* b* system, respectively, using a colorimeter. STATISTICAL ANALYSIS: For intergroup statistical analysis, ANOVA with Tukey's posttest was used. All tests were calculated at a significance level of 5%. RESULTS: There was statistically significant difference (P < 0.01) between the analyzed groups, on VHN, Ra, and CT evaluations. CONCLUSIONS: The use of fluoride-based dentifrice at 5000 ppm was effective in minimizing the deleterious effects on bleached enamel.

Multidisciplinary aesthetic rehabilitation: case report

Objective: This work aims to report a clinical case that performed the aesthetic rehabilitation of a patient through the integration of different dental specialties (Orthodontics, Periodontics and Dentistry). Case Report: An 18-year-old female patient received compensatory orthodontic treatment for correction of class II malocclusion, overbite and overjet, and interproximal diastema. After orthodontictreatment, a gingivoplasty was performed to remove excess gingival tissue and increase the crown of the teeth, and a frenectomy for the anomalous labial frenulum removal. After periodontal treatment the in-office bleaching was conducted, and the diastema was closed with microhybrid composite resins. Conclusion: It was concluded that multiprofessional planning made possible the aesthetic / functional rehabilitation of the patient.

Objetivo: Este trabalho visa relatar um caso clínico que realizou a reabilitação estética de um paciente por meio da integração de diferentes especialidades odontológicas (Ortodontia, Periodontia e Dentística). Relato do Caso: Paciente do sexo feminino, com 18 anos, recebeu tratamento ortodôntico compensatório para correção de má-oclusão classe II, overbite e overjet acentuados, e diastemas interproximais. Após tratamento ortodôntico, foi realizada uma gengivoplastia para a remoção do excesso de tecido gengival e aumento da coroa dos dentes, e uma frenectomia para a remoção do freio labial anômalo. Após o tratamento periodontal, foi realizado um clareamento dentário de consultório, e o fechamento dos diastemas anterosuperiores e o recontorno da cosméticados dentes com resinas compostas microhíbridas. Conclusão: Concluiu-se que o planejamento integrado multiprofissional possibilitou o êxito da reabilitação estética/funcional do paciente.