Remineralizing effect of the association of nano-hydroxyapatite and fluoride in the treatment of initial lesions of the enamel: A systematic review.

OBJECTIVE: Assessed the effect of dental products containing nano-hydroxyapatite (nano-HA) + fluoride on the remineralization of white spot lesions (WSL) in vivo or in situ. METHODS: Seven databases were explored using a two-pronged approach (intervention/treatment). After screening, full-text assessment, and further exclusion, the qualitative synthesis of five studies (four clinical and one in situ) was performed. Based on the Cochrane collaboration guidelines relevant data of the studies were collected and summarized. The Cochrane risk of bias tool for randomized trials (RoB 2.0) was used to appraise the studies' methodological quality and the GRADE guidelines to assess their level of evidence. The RoB 2.0 domains were rated on their risk of bias (RoB) as low, high, or with some concerns, and an adaptation of the tool was used to the in situ study. RESULTS: The included studies assessed 151 WSL in anterior permanent teeth, on patients with varying ages. The protocol application, treatment length (7d-12 w), and control groups varied greatly between the studies making the performance of a quantitative analysis unfeasible. The general RoB of the clinical studies was classified as being of low risk (n = 2) or some concerns (n = 2). The in situ study was considered as being of low risk. The level of the evidence was moderate. Most of the studies found moderate evidence regarding the superiority of this association in clinical settings. CONCLUSION: Even with the nano-HA + fluoride promising results for the remineralization treatment of WSL, due to the restricted number of studies and types of products, its extended use cannot be recommended based on the current systematic review, especially when considering the moderate level of the evidence found. CLINICAL SIGNIFICANCE: Due to the biocompatibility and higher surface coverage of nano-HA and the remineralization capacity of fluoride formulations, the association of these elements to remineralize WSL has been positively reported. After the collection and qualitative appraise of the data, the clinical evidence of the use of these dental products is promising but limited.

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.

The effect of photobiomodulation therapy associated with casein phosphopeptide-amorphous calcium phosphate fluoride paste on the treatment of posthome whitening tooth sensitivity and color change: A randomized clinical trial.

OBJECTIVE: This study assessed whether combining photobiomodulation therapy (PBMT) with casein phosphopeptide-amorphous calcium phosphate fluoride (CPP-ACPF) paste can effectively reduce post-home whitening tooth sensitivity (TS) without compromising shade change. METHODS: Fifty participants were selected and assigned to one of four groups: (1) PLACEBO group-received a placebo paste and PBMT simulation; (2) PBMT group-received a placebo paste + PBMT; (3) CPP-ACPF group-received CPP-ACPF paste and PBMT simulation; (4) CPP-ACPF + PBMT group-received both CPP-ACPF paste and PBMT. The participants used whitening trays containing 22% carbamide peroxide for 2 h a day for 21 days. TS was measured daily using a visual analog scale, while shade change was assessed using a spectrophotometer: before bleaching treatment (T0), after the first (T1), second (T2), and third (T3) weeks of treatment, and 30 days (T4) after completing the whitening treatment. RESULTS: Intragroup analysis revealed that the PLACEBO group had the highest increase in sensitivity during the whitening treatment. The CPP-ACPF and PBMT groups showed no significant difference tooth whitening (TW) between weeks regarding aesthetic change. The CPP-ACPF and PBMT group exhibited a significant reduction in TS between the first and third and between the second and third weeks TW, but not between the first and second. Conversely, the PLACEBO group showed a higher sensitivity than the other groups (p < .05). The CPP-ACPF and PBMT groups did not differ from each other. Furthermore, the CPP-ACPF and PBMT group showed a greater decrease in sensitivity than the PLACEBO group at T1, T2, and T3 (p < .01), and was significantly differed from CPP-ACPF and PBMT groups only at T2 and T3. All groups confirmed TW effectiveness. Student's and paired t-test did not reveal any significant difference between groups (p > .05). CONCLUSION: Therefore, PBMT associated with CPP-ACPF paste can reduce TS without compromising the efficacy of TW.

Formulations of NaOCl-based in liquid, gel form or with surfactants on dentin deproteinization before fiber post cementation.

The objective of the study was to evaluate the effects of dentin deproteinization protocols for post space using different formulations containing sodium hypochlorite before fiber post cementation with self-adhesive resinous cement. The groups were divided according to the irrigation protocol (DWC, SHS, SHT and SHG). The residue cleanliness, bond strength, adhesive failure pattern, and tag formation at the adhesive interface between the self-adhesive cement and the dentin were evaluated. For this, analysis in scanning electron microscope, push-out test and confocal laser scanning microscopy were performed. The SHT protocol showed the highest residue cleanliness on the dentin surface of the post space (p<0.05). In addition, SHT protocol showed highest bond strength and tag formation in the cervical and middle thirds (p<0.05). Dentin deproteinization with sodium hypochlorite with surfactant provided the best dentin cleaning of residues, bond strength and tag formation after cementation of the fiber post with self-adhesive cement.

Influence of using different translucent composite resins for customizing fiber post on the bond strength of self-adhesive cement to root dentin.

This study evaluated the influence of different translucent resins (Z350 and Opallis) for customizing fiber posts and light-curing the cementation system using different LED equipment (V, Valo or R, Radii-Cal) on the bond strength and adhesive failure pattern at 24 h and 6 months. Eighty roots were prepared and divided into 4 groups (n=20): ZV (Z350 resin and LED Valo), ZR (Z350 resin and LED Radii-Cal), OV (Opallis resin and LED Valo), OR (Opallis resin and LED Radii-Cal). After post space preparation, the fiber post was customized and cemented with self-adhesive cement and light-curing using V or R LED equipment. Bond strength values were submitted to 2-way ANOVA test. ZV and ZR showed higher bond strength values than the other groups at 6 months of evaluation (p<0.05). The Z350 resin has a favorable influence on the bond strength of self-adhesive cement to root dentin, regardless of the LED polymerization equipment used.

Fracture resistance and bonding performance after antioxidants pre-treatment in non-vital and bleached teeth.

This study aimed to evaluate the effect of antioxidant solutions on fracture strength and bonding performance in non-vital and bleached (38% hydrogen peroxide) teeth. One hundred and eighty dentin specimens were obtained, 60 for each test: fracture strength, hybrid layer thickness, and bond strength. The groups (n=10) were randomly composed according to post-bleaching protocol: REST - restoration, without bleaching; BL - bleaching + restoration; SA - bleaching, 10% sodium ascorbate solution, and restoration; AT - bleaching, 10% α-tocopherol solution, and restoration; CRAN - bleaching, 5% cranberry solution, and restoration; CAP - bleaching, 0.0025% capsaicin solution, and restoration. Data were analyzed with ANOVA, Kruskal-Wallis, Dunn, and Qui-Square tests (α=0.05). The highest fracture strength values were observed in REST (1508.96 ±148.15 N), without significant difference for the bleached groups (p>0.05), regardless of the antioxidant use. The hybrid layer thickness in the group that was not subjected to bleaching (REST) was significantly higher than in any other group. The bond strength in the bleached and antioxidants-treated groups (SA, AT, CRAN, CAP) has no differences with the bleached group without antioxidants (BL). Adhesive failures were predominant in the groups that did not receive the antioxidant application. In conclusion, the evaluated antioxidants did not show an effect on the fracture strength, hybrid layer thickness, or bond strength of dentin bleached after endodontic treatment. The application of 10% sodium ascorbate, 10% alpha-tocopherol, 5% cranberry, or 0.0025% capsaicin solutions is not an effective step and should not be considered for the restorative protocols after non-vital bleaching.

Fracture resistance and bonding performance after antioxidants pre-treatment in non-vital and bleached teeth

Abstract This study aimed to evaluate the effect of antioxidant solutions on fracture strength and bonding performance in non-vital and bleached (38% hydrogen peroxide) teeth. One hundred and eighty dentin specimens were obtained, 60 for each test: fracture strength, hybrid layer thickness, and bond strength. The groups (n=10) were randomly composed according to post-bleaching protocol: REST - restoration, without bleaching; BL - bleaching + restoration; SA - bleaching, 10% sodium ascorbate solution, and restoration; AT - bleaching, 10% α-tocopherol solution, and restoration; CRAN - bleaching, 5% cranberry solution, and restoration; CAP - bleaching, 0.0025% capsaicin solution, and restoration. Data were analyzed with ANOVA, Kruskal-Wallis, Dunn, and Qui-Square tests (α=0.05). The highest fracture strength values were observed in REST (1508.96 ±148.15 N), without significant difference for the bleached groups (p>0.05), regardless of the antioxidant use. The hybrid layer thickness in the group that was not subjected to bleaching (REST) was significantly higher than in any other group. The bond strength in the bleached and antioxidants-treated groups (SA, AT, CRAN, CAP) has no differences with the bleached group without antioxidants (BL). Adhesive failures were predominant in the groups that did not receive the antioxidant application. In conclusion, the evaluated antioxidants did not show an effect on the fracture strength, hybrid layer thickness, or bond strength of dentin bleached after endodontic treatment. The application of 10% sodium ascorbate, 10% alpha-tocopherol, 5% cranberry, or 0.0025% capsaicin solutions is not an effective step and should not be considered for the restorative protocols after non-vital bleaching.

Resumo Este estudo teve como objetivo avaliar o efeito de soluções antioxidantes na resistência à fratura e resistência de união em dentes tratados endodonticamente e clareados (38% de peróxido de hidrogênio). Cento e oitenta espécimes de dentina foram obtidos, 60 para cada teste: resistência à fratura, espessura da camada híbrida e resistência de união. Os grupos (n=10) foram compostos aleatoriamente de acordo com o protocolo pós-clareamento: REST - restauração, sem clareamento; BL - clareamento + restauração; SA - clareamento, solução de ascorbato de sódio a 10% e restauração; AT - clareamento, solução de α-tocoferol a 10% e restauração; CRAN - clareamento, solução de cranberry a 5% e restauração; CAP - clareamento, solução de capsaicina 0,0025% e restauração. Os dados foram analisados ​​com os testes ANOVA, Kruskal-Wallis, Dunn e Qui-Quadrado (α=0,05). Os maiores valores de resistência à fratura foram observados em REST (1508,96 ±148,15 N), sem diferença significativa para os grupos clareados (p>0,05), independente do uso de antioxidantes. A espessura da camada híbrida no grupo que não foi submetido ao clareamento (REST) foi significativamente maior do que em qualquer outro grupo. A resistência de união nos grupos clareado e tratado com antioxidantes (SA, AT, CRAN, CAP) não apresentou diferenças com o grupo branqueado sem antioxidantes (BL). As falhas adesivas foram predominantes nos grupos que não receberam a aplicação do antioxidante. Em conclusão, os antioxidantes avaliados não mostraram efeito sobre a resistência à fratura, espessura da camada híbrida ou resistência de união à dentina clareada após tratamento endodôntico. A aplicação de soluções de ascorbato de sódio 10%, alfa-tocoferol 10%, cranberry 5% ou capsaicina 0,0025% não é uma etapa eficaz e não deve ser considerada para os protocolos restauradores após clareamento não vital.

Anti-erosion effect of an experimental varnish on eroded dentin.

This in vitro study evaluated the effect of an experimental varnish containing 20% nano-hydroxyapatite (nHAP) associated with 5% stannous chloride (SnCl2) against erosive-abrasive wear on bovine dentin. Samples of bovine cervical dentin were pre-eroded (0.3% citric acid, pH 2.6 for 10 minutes) and randomized into 4 groups (n=10): Control group - experimental varnish without active ingredient (CG); experimental varnish containing 20% nHAP (nHG); experimental varnish containing 5% SnCl2 (24.800 ppm Sn2+) (SnG); experimental varnish containing 20% nHAP associated with 5% SnCl2 (18.300 ppm Sn2+) (nHSnG). After applying the materials, the erosive-abrasive challenges were performed for five days. Erosive dentin loss and analysis of the pattern of dentinal obliteration were performed by 3D confocal laser microscopy. A one-way ANOVA/Bonferroni test was performed to analyze the data (α=0.05). The SnG and nHSnG experimental groups presented more effectiveness in preventing erosive wear when compared to the other groups (p<0.05). There was no statistically significant difference between the SnG and nHSnG groups (p = 0.731) in tooth structure dentin loss. Regarding the amount of open dentinal tubules, the highest amount of obstructed dentinal tubules was demonstrated in SnG and nHSnG (p < 0.05) when compared to the others. Between SnG and nHSnG there was no significant difference (p = 0.952) in the amount of closed dentinal tubules in the dentin. Experimental varnishes containing 5% SnCl2 associated or not with 20% nHAP showed to be a promising strategy in preventing erosive-abrasive wear of dentin. In addition, nHSnG was able to obliterate dentinal tubules.

Anti-erosion effect of an experimental varnish on eroded dentin

Abstract This in vitro study evaluated the effect of an experimental varnish containing 20% nano-hydroxyapatite (nHAP) associated with 5% stannous chloride (SnCl2) against erosive-abrasive wear on bovine dentin. Samples of bovine cervical dentin were pre-eroded (0.3% citric acid, pH 2.6 for 10 minutes) and randomized into 4 groups (n=10): Control group - experimental varnish without active ingredient (CG); experimental varnish containing 20% nHAP (nHG); experimental varnish containing 5% SnCl2 (24.800 ppm Sn2+) (SnG); experimental varnish containing 20% nHAP associated with 5% SnCl2 (18.300 ppm Sn2+) (nHSnG). After applying the materials, the erosive-abrasive challenges were performed for five days. Erosive dentin loss and analysis of the pattern of dentinal obliteration were performed by 3D confocal laser microscopy. A one-way ANOVA/Bonferroni test was performed to analyze the data (α=0.05). The SnG and nHSnG experimental groups presented more effectiveness in preventing erosive wear when compared to the other groups (p<0.05). There was no statistically significant difference between the SnG and nHSnG groups (p = 0.731) in tooth structure dentin loss. Regarding the amount of open dentinal tubules, the highest amount of obstructed dentinal tubules was demonstrated in SnG and nHSnG (p < 0.05) when compared to the others. Between SnG and nHSnG there was no significant difference (p = 0.952) in the amount of closed dentinal tubules in the dentin. Experimental varnishes containing 5% SnCl2 associated or not with 20% nHAP showed to be a promising strategy in preventing erosive-abrasive wear of dentin. In addition, nHSnG was able to obliterate dentinal tubules.

Resumo Este estudo in vitro avaliou o efeito de um verniz experimental contendo 20% de nano-hidroxiapatita (nHAP) associado a 5% de cloreto estanoso (SnCl2) contra o desgaste erosivo-abrasivo da dentina bovina. As amostras de dentina cervical bovina foram pré-erodificadas (0,3% de ácido cítrico, pH 2,6 durante 10 minutos) e aleatorizadas em 4 grupos (n=10): Grupo controle - verniz experimental sem ingrediente ativo (GC); verniz experimental contendo 20% nHAP (GnH); verniz experimental contendo 5% SnCl2 (24.800 ppm Sn2+) (GSn); verniz experimental contendo 20% nHAP associado a 5% SnCl2 (18.300 ppm Sn2+) (GnHSn). Após a aplicação dos materiais, os desafios erosivo-abrasivos foram realizados durante cinco dias. Perda de dentina erosiva e análise do padrão de obliteração dentinária foram realizadas por microscopia laser confocal 3D. Foi realizado o teste ANOVA/Bonferroni unidireccional para analisar os dados (α=0,05). Os grupos experimentais GSn e GnHSn apresentaram maior eficácia na prevenção do desgaste erosivo quando comparados com os outros grupos (p<0,05). Não houve diferença estatisticamente significativa entre os grupos GSn e GnHSn (p = 0,731) na perda de dentina da estrutura dentária. Relativamente à quantidade de túbulos dentinários abertos, a maior quantidade de túbulos dentinários obstruídos foi demonstrada em GSn e GnHSn (p < 0,05) quando comparada com os outros grupos. Entre GSn e GnHSn, não houve diferença significativa (p = 0,952) na quantidade de túbulos dentinários fechados na dentina. Os vernizes experimentais contendo 5% de SnCl2 associados ou não a 20% de nHAP mostraram ser uma estratégia promissora na prevenção do desgaste erosivo-abrasivo da dentina. Além disso, o GnHSn conseguiu obliterar os túbulos dentinários.

Etch-and-rinse versus self-etch strategy of a universal adhesive in different application methods at the bonding interface of fiber post cementation.

OBJECTIVE: To evaluate the effect of etch-and-rinse (ER) versus self-etch (SE) strategies of a universal adhesive applied with a manual brush (MB) or rotary brush (RB) on the bonding interface of fiber post cementation. METHODS: Forty bovine incisor roots were prepared and divided into four groups according to the methods of application and strategy of universal adhesive use (MB-ER, RB-ER, MB-SE and RB-SE). After 6 months, specimens from different thirds of the post space were evaluated of push-out strength, analysis of adhesive failure patterns, and extent of tags. RESULTS: The RB-ER and RB-SE groups showed the highest bond strength values in the cervical and middle thirds of the post space. Cohesive adhesive failure had the highest incidence in the different thirds of the post space in the ER strategy, regardless of the adhesive application method. The RB-ER group showed the highest tag extensions. CONCLUSIONS: The protocols of universal adhesive application with RB provided the greater bond strength, but only the ER strategy favored the formation of a greater extension of tags at the adhesive interface. CLINICAL SIGNIFICANCE: The application of universal adhesive with RB into the post space increases the strength of the post-cemented fiber bond.

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.

Solução estética conservadora em paciente jovem com fluorose: clareamento e microabrasão: relato de caso / Conservative aesthetic solution in a young patient with fluorosis: whitening and microabrasion: case report

Introdução: a fluorose constitui uma patologia que afeta os dentes desencadeada pelo excesso de ingestão de flúor. Sua manifestação ocorre a nível de esmalte na presença de manchas ou defeitos anatômicos. Objetivo: relatar o manejo clínico de um paciente com fluorose tratado com procedimento minimamente invasivo. Relato do caso: paciente do sexo feminino, 18 anos, apresentando queixas estéticas clinicamente observadas na vestibular dos dentes, com diagnóstico de lesões fluoróticas. Foi executado protocolo de dessensibilização com Ultra EZ por 5 min e aplicação do Verniz (Enamelast Fluoride) previamente ao tratamento clareador. Foram realizados duas sessões de clareamento com peróxido de hidrogenio 35% (DMC) por 45 min com intervalo de sete dias entre elas. Imediatamente após a segunda sessão de clareamento, foi realizado microabrasão com pasta abrasiva Whitness RM (FGM) e taça de borracha com fricção por 20 segundos. Resultados: o tratamento clareador associado a técnica da microabrasão do esmalte demonstrou resultado estético favorável, microinvasivo e eficaz no tratamento da fluorose. Conclusão: a associação dos tratamentos resolveu o problema estético da paciente de forma rápida e segura, conservando a estrutura dentária.

Introduction: fluorosis is a pathology that affects teeth triggered by excess fluoride intake. Its manifestation occurs at the enamel level in the presence of stains or anatomical defects. Objective: to report the clinical management of a patient with fluorosis treated with a minimally invasive procedure. Case report: female patient, 18 years old, presenting aesthetic complaints clinically observed in the buccal of the teeth, with a diagnosis of fluorotic lesions. A desensitization protocol was performed with Ultra EZ for 5 min and Varnish (Enamelast Fluoride) was applied prior to the bleaching treatment. Two bleaching sessions were performed with 35% hydrogen peroxide (DMC) for 45 min, with an interval of seven days between them. Immediately after the second bleaching session, microabrasion was performed with Whitness RM abrasive paste (FGM) and a rubber cup with friction for 20 seconds. Results: The bleaching treatment associated with the enamel microabrasion technique demonstrated a favorable, microinvasive and effective esthetic result in the treatment of fluorosis. Conclusion: the combination of treatments solved the patient's aesthetic problem quickly and safely, preserving the dental structure.

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.

Influence of different glaze firing protocols on the mechanical properties of CAD-CAM ceramic materials.

STATEMENT OF PROBLEM: The influence of different glaze firing protocols and cooling on the behavior of computer-aided design and computer-aided manufacturing (CAD-CAM) ceramics is unclear. PURPOSE: The purpose of this in vitro study was to investigate the influence of different glaze firing protocols on the abrasion resistance, surface roughness, microhardness, and brittleness index of CAD-CAM ceramics. MATERIAL AND METHODS: Rectangular specimens of IPS e.max CAD (MAX), IPS Empress CAD (PRE), and CEREC Blocs (CER) were obtained and divided into 5 groups according to the glaze firing protocol (n=8): control (CO), 1 conventional glaze firing (GF), 2 conventional glaze firings (GF2), 1 extended glaze firing (EG), and 2 extended glaze firings (EG2). The coefficient of friction (µ) was determined with the pin-on-disk test, and specimens were analyzed with an optical interferometer to calculate volume loss and roughness. Vickers microhardness and the brittleness index were obtained with a microdurometer. Microhardness data were evaluated by 2-way ANOVA and the Sidak tests (α=.05). Data from other tests were assessed with nonparametric ANOVA and Bonferroni tests (α=.05). RESULTS: Groups GF2, EG, and EG2 of MAX and PRE and all groups of CER presented higher levels of coefficient of friction. Groups EG and EG2 of MAX and CER showed high volume loss and surface roughness. Groups EG and EG2 of MAX and PRE showed lower hardness, as did all groups of CER. MAX-CO and groups GF and EG of PRE showed a lower brittleness index (P<.05), while CER groups showed no significant differences (P>.05). CONCLUSIONS: Ceramic specimens with conventional glaze firing presented less surface wear than those with extended glaze firing. The number of firings did not have a statistically significant influence.

Bond strength and internal adaptation of customized glass fiber posts using different bulk-fill flow resins.

Background: This study aimed to evaluate the bond strength and internal adaptation of customized glass fiber posts using Bulk Fill flowable composite resins (BF) and conventional composite resin. Material and Methods: Fifty bovine teeth were randomly divided (n=10) according to the following groups: G1 (control): glass fiber posts were adapted to the root canal and luted with Rely-X ARC cement (3M® ESPE); G2: fiber posts smaller than the root canal diameter were customized using Filtek™ Z350 XT (3M® ESPE) conventional composite resin, and luted similarly to Group 1. G3: posts were customized with Tetric N-Ceram Bulk Fill composite resin (Ivoclar Vivadent AG), G4: posts were customized with Filtek™ Bulk Fill Flow (3M® ESPE), and G5: posts were customized with SureFil SDRTM flow (DENTSPLY), respectively. The specimens were submitted to push-out testing and internal adaptation evaluation using optical microscopy. Push-out (MPa) and internal adaptation (%) data were subjected to ANOVA and Tukey's post-hoc tests (p = 5%). Results: No statistically significant differences were found in both evaluations (p<0.05). Conclusions: Customized glass fiber posts using different bulk fill flowable composites did not affect the post bond-strength and internal adaptation, presenting similar results to customized glass fiber posts using conventional composite or posts with no previous customization. Key words:Dental pulp, composite resins, fiber posts, glass fiber post.

Anti-erosive profile of an experimental 5% SnCl2 varnish containing different concentrations of NaF.

This in vitro study evaluated the anti-erosive effect of an experimental varnish containing 5% stannous chloride (SnCl2) associated with different concentrations of NaF (NaF-free, 2.5% NaF, or 5.2% NaF) on bovine enamel and root dentin. One hundred samples were pre-eroded (0.3% citric acid, pH 2.6, 10 min) and randomized into five groups (n=10 for each substrate): Negative control - milli-Q water; NaF-free - Experimental varnish SnCl2-free and NaF-free; 2.5 NaF - Experimental varnish 5% SnCl2 associated with 2.5% NaF; 5.2 NaF: Experimental varnish 5% SnCl2 associated with 5.2% NaF and positive control - Commercial varnish containing 5% NaF (Duraphat). After the varnishes were applied, the erosive and abrasive challenges were carried out for five days. Loss of tooth structure (TSL) was determined by optical profilometry, and the loss of calcium (ΔCa2+) using atomic absorption spectroscopy. Dentin analysis was also performed by SEM. A one-way ANOVA/Bonferroni test was performed to analyze the data (α=0.05). The experimental 2.5 NaF and 5.2 NaF groups showed greater effectiveness in preventing TSL when compared to the other groups (p <0.05), regardless of the substrate. In addition, these groups showed lower loss in Ca2+ content when compared to the other groups (p <0.05), for enamel and dentin. Dentin showed greater TSL and ΔCa2+ loss when compared to enamel in all treatments (p <0.05). The 5.2% and 2.5% NaF-containing experimental varnishes showed promising results in both, the prevention of TSL and the loss of Ca2+, regardless of the substrate studied.

Anti-erosive profile of an experimental 5% SnCl₂ varnish containing different concentrations of NaF

Abstract This in vitro study evaluated the anti-erosive effect of an experimental varnish containing 5% stannous chloride (SnCl₂) associated with different concentrations of NaF (NaF-free, 2.5% NaF, or 5.2% NaF) on bovine enamel and root dentin. One hundred samples were pre-eroded (0.3% citric acid, pH 2.6, 10 min) and randomized into five groups (n=10 for each substrate): Negative control - milli-Q water; NaF-free - Experimental varnish SnCl₂-free and NaF-free; 2.5 NaF - Experimental varnish 5% SnCl₂ associated with 2.5% NaF; 5.2 NaF: Experimental varnish 5% SnCl₂ associated with 5.2% NaF and positive control - Commercial varnish containing 5% NaF (Duraphat). After the varnishes were applied, the erosive and abrasive challenges were carried out for five days. Loss of tooth structure (TSL) was determined by optical profilometry, and the loss of calcium (ΔCa2+) using atomic absorption spectroscopy. Dentin analysis was also performed by SEM. A one-way ANOVA/Bonferroni test was performed to analyze the data (α=0.05). The experimental 2.5 NaF and 5.2 NaF groups showed greater effectiveness in preventing TSL when compared to the other groups (p <0.05), regardless of the substrate. In addition, these groups showed lower loss in Ca2+ content when compared to the other groups (p <0.05), for enamel and dentin. Dentin showed greater TSL and ΔCa2+ loss when compared to enamel in all treatments (p <0.05). The 5.2% and 2.5% NaF-containing experimental varnishes showed promising results in both, the prevention of TSL and the loss of Ca2+, regardless of the substrate studied.

Resumo Este estudo in vitro avaliou o efeito anti-erosivo de um verniz experimental contendo 5% de cloreto estanoso (SnCl₂) associado a diferentes concentrações de NaF (sem NaF, 2,5% NaF ou 5,2% NaF) sobre esmalte e dentina radicular bovinos. Cem amostras foram pré-erodidas (ácido cítrico 0,3%, pH 2,6, 10 min) e randomizadas em cinco grupos (n=10 para cada substrato): Controle negativo - água milli-Q; Sem NaF - Verniz experimental sem SnCl2 e sem NaF; 2,5 NaF - Verniz experimental 5% SnCl2 associado a 2,5% NaF; 5,2 NaF: Verniz experimental 5% SnCl2 associado a 5,2% NaF e controle positivo - Verniz comercial contendo 5% NaF (Duraphat). Após a aplicação dos vernizes, os desafios erosivos e abrasivos foram realizados por cinco dias. A perda de estrutura dentária (PED) foi determinada por perfilometria óptica e a perda de cálcio (ΔCa2+) por espectroscopia de absorção atômica. A análise da dentina também foi realizada por MEV. Um teste ANOVA/Bonferroni de uma via foi realizado para analisar os dados (α=0,05). Os grupos experimentais 2,5 NaF e 5,2 NaF apresentaram maior eficácia na prevenção de PED quando comparados aos demais grupos (p<0,05), independentemente do substrato. Além disso, esses grupos apresentaram menor perda no teor de Ca2+ quando comparados aos demais grupos (p<0,05), para esmalte e dentina. A dentina apresentou maior PED e de ΔCa2+ quando comparada ao esmalte em todos os tratamentos (p<0,05). Os vernizes experimentais contendo NaF 5,2% e 2,5% apresentaram resultados promissores tanto na prevenção de PED quanto na perda de Ca2+, independente do substrato estudado.

Impact of Finishing Protocols on Color Stability of CAD/CAM Ceramics: A Systematic Review.

PURPOSE: To analyze the current evidence on the impact of surface finishing protocols (such as manual polishing or glazing) on the color stability of in vitro simulated pigmentation of CAD/CAM ceramics. MATERIALS AND METHODS: Five electronic databases were searched on February 12, 2020. In vitro experimental studies were included based on the following strategy: intervention = surface treatment of CAD/CAM ceramics with glazing agents; comparison = surface treatment of CAD/CAM ceramics with manual polishing; and outcomes = color stability. Two reviewers independently assessed the risk of bias. RESULTS: Among 1,390 articles that were screened, 6 in vitro studies were considered for qualitative analysis. Five articles confirmed changes in the color of ceramics when they were immersed in pigmented solutions. One article investigated the color stability of the samples via ultraviolet (UV) aging. Among the 6 studies analyzed, 4 showed clinically acceptable color alteration values represented by ΔE irrespective of the finishing protocol applied (glazing or mechanical polishing). Two articles presented clinically unsatisfactory color variation (ΔE > 3.3 and ΔE > 2.7) following mechanical polishing of a zirconia-reinforced lithium silicate ceramic. Coffee and red wine proved to be the beverages with the greatest potential for ceramic pigmentation. Only 1 article had a high risk of bias. CONCLUSION: For clinicians, most of the studies demonstrated that both manual polishing and glaze application can prevent significant color alterations on CAD/CAM ceramic surfaces. However, due to the relatively limited amount of evidence to support this conclusion, further studies must be conducted.