Evaluation of bond strength in customizing fiber post using translucent resins photoactivated by different light-emitting diodes.

Aims: The objective of the study was to evaluate two translucent resin composite systems for customizing light-polymerized fiber posts with light-emitting diode (LED) curing units regarding adhesion using conventional cement at 24 h and 6 months. Settings and Design: This was an experimental in vitro study. Methods: Forty roots were prepared and divided into four groups (n = 10): ZV-Z350 resin and LED Valo; ZR-Z350 resin and LED Radii-Cal; OV-Opallis resin and LED Valo; and OR-Opallis resin and LED Radii-Cal. The fiber post was customized and cemented with conventional resin cement and was photoactivated by two different sources. Statistical Analysis Used: The data were subjected to two-way ANOVA and Tukey's post hoc tests (P = 0.05). The data regarding the pattern of adhesive failures were described in terms of the frequency of occurrence in each third of the postspace. Results: Both at 24 h and 6 months, bond strength among groups was similar, regardless of the analyzed postspace 3rd (P > 0.05). Adhesive failure Type 4 was the most frequent in all thirds. Conclusions: Customizing the fiber post with Z350 and Opallis has the same effect on bond strength and adhesive failure pattern, regardless of the LED curing units used for photopolymerization.

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.

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.

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.

Effect of LEDs with Different Wavelengths on the Microhardness and Nanohardness of Nanohybrid Composite Resins.

AIM: The aim of this study is to compare the effectiveness of polymerization of nanohybrid composite resins with different colors and thicknesses, photocured by units of different wavelengths through Knoop microhardness (KHN) and Berkovich nanohardness (DUH). MATERIALS AND METHODS: One hundred twenty specimens of Tetric N-Ceram (Ivoclar/Vivadent) were divided into groups (n = 5) according to the experimental test, the color of the composite resin (A2 and Bleach-M/BM), the light source: monowave (Elipar™ FreeLight DeepCure-3M/ESPE), dental products-1200 mW/cm2/15 seconds (FL); or polywave (Bluephase-Ivoclar/Vivadent 1200 mW/cm2/15 and 30 seconds (BP), and thickness (irradiated surface,1, 2, and 3 mm). The specimens were stored dry for 24 hours at 37°C and received five indentations on the top and button surfaces. Analysis of variance (ANOVA), Tukey, and Pearson correlation (p < 0.01%) tests were used. RESULTS: A direct correlation was found between KHN and DUH. The higher values of KHN and DUH were observed with Elipar™ FreeLight DeepCure unit in irradiated surface and 1-mm-thick specimens at A2 color. CONCLUSION: That Elipar™ FreeLight DeepCure unit showed better effectiveness in curing nanohybrid composite resins, used in this work, in different colors and depths as compared to Bluephase in both experimental tests, and that DUH can substitute KHN test when comparing the effectiveness of polymerization. CLINICAL SIGNIFICANCE: The evaluation of the mechanical properties of composite resins is essential to verify their possible clinical performance.

Temporary cement residues affect the bond strength and dentin penetration of self-adhesive resin cement in fiberglass post cementation.

This study evaluated the persistence of eugenol-containing (PR, Provy) or eugenol-free (RT, Relyx Temp, and TB, Temp Bond) temporary cement residues and its effects on push-out bond strength and dentinal penetration of the self-adhesive resin cement (Relyx U200). Eighty human roots were endodontically treated and post space prepared. Fourty specimens were distributed in four groups (n = 10): Control (CO), without any clinical procedure, PR, RT, and TB, where a metallic post was cemented with one of the temporary cements. After metallic post removal, hemi sections post space were submitted to SEM analysis. Another specimens were distributed in similar groups, but fiberglass post was cemented using Relyx U200 cement and submitted to push-out bond strength and dentinal penetration cement analysis, in post space thirds. SEM analysis were evaluated by Kruskal-Wallis and Dunn tests, while bond strength and dentinal penetration were evaluated by ANOVA One-Way and Tukey test (p < .05). Only in apical thirds, PR, RT, and TB showed higher persistence of residues than CO. In bond strength, PR, RT, and TB showed lower values than CO, in all post space thirds (p < .05). But to dentinal penetration, PR, RT, and TB presented lower values than CO only in apical thirds (p < .05). There is the greatest persistence of temporary cement residues only in apical post space third, providing less dentinal penetration of the self-adhesive resinous cement. However, the previous use of temporary cements has negative effects on the bond strength cementation system, regardless of the third evaluated.

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.

Clinical efficacy of nano-hydroxyapatite in dentin hypersensitivity: A systematic review and meta-analysis.

OBJECTIVES: To evaluate the desensitizing effect of nano-hydroxyapatite (n-HAP) on dentine hypersensitivity (DH). SOURCES: Seven electronic databases were searched on April 27, 2018. STUDY SELECTION: Randomized clinical trials (RCTs) were included based on the PICO strategy: Participants - Humans with DH; Intervention - n-HAP-containing desensitizing; Comparison -n-HAP-free treatments or placebo/negative control; and Outcomes - relief of DH. The risk of bias was classified by the Cochrane guidelines. Five meta-analyses were performed to evaluate the efficacy of n-HAP with regard to pain assessment stimuli (primary outcome); comparison of n-HAP with other treatments or placebo/negative control, and effectiveness of at-home and in-office n-HAP use (secondary outcomes). The quality of the evidence was evaluated using the GRADE. DATA: Six RCTs with 4 weeks of follow-up were included in the meta-analysis. For the primary outcome, n-HAP showed a better desensitizing effect for evaporative stimuli (SMD -1.09 [-1.24, -0.94], p < 0.00001) and tactile stimuli (SMD -0.93 [-1.42, -0.43]) than other treatments (p = 0.0002). However, there was no difference between n-HAP and other treatments for the cold stimuli (SMD -0.17 [-0.81, 0.48], p = 0.61). In an overall analysis, n-HAP-containing treatment showing the most significant desensitizing effect (SMD -0.93 [-1.19, -0.68], p < 0.00001) with a high quality of evidence for pooled results. In the secondary outcomes, n-HAP showed the best effect in the overall analysis (p < 0.05) with moderate quality evidence. CONCLUSIONS: The n-HAP-containing treatment showed better clinical performance than other treatments for DH relief. However, long-term follow-up RCTs are required in the future before definitive recommendations can be made. CLINICAL SIGNIFICANCE: Dentin hypersensitivity is a common global condition and its multifactorial etiology has led to the development of several treatments. The n-HAP-containing treatment showed greater DH relief when compared to other desensitizing agents, placebo or negative control.

An in situ Evaluation of Bioactives on the Morphology of Bleached Enamel.

AIM: The aim of this study was to use surface rugosity analysis (Ra) and scanning electron microscopy (SEM) comparing effects of nano-hydroxyapatite (NANO), casein phosphopeptide-amorphous calcium phosphate (CPP-ACP), and NovaMin (NOVA) on enamel's human morphology bleached with 37.5% hydrogen peroxide. MATERIALS AND METHODS: Forty specimens (3 × 3 × 3 mm) were obtained from fully included third molars and four specimens were attached in the first molars of the volunteers. The POLA-positive control has only been bleached. Three experimental groups were bleached and treated with respective bioactive: NANO, CPP-ACP, and NovaMin. The Ra analyses were performed before and after the treatment using a rugosimeter. The obtained photomicrographs were analyzed using SEM (n = 3) by three examiners, and the study was double blind. RESULTS: The Ra results were analyzed by one-way analysis of variance and Tukey's post hoc test (p < 0.05). All experimental groups showed significant differences of the others; however, the experimental groups were not significantly different from each other. CONCLUSION: The enamel morphology of the bioactive-treated groups had more regular surfaces, than the others.