Efficacy of seventh generation bonding agents as desensitizers in patients with dentin hypersensitivity: a randomized clinical trial.

BACKGROUND: Dentin hypersensitivity (DH) is one of the most challenging and persistent dental complaints characterized by transient, intense pain triggered by various stimuli. It affects a significant portion of the global population, predominantly those aged 20-40. This study aims to evaluate the desensitizing efficacy of seventh-generation dentin bonding agents (Single Bond Universal by 3 M ESPE and Xeno-V + by Dentsply) against a control group using Bifluorid 12 by Voco in mitigating DH within a month of the follow-up period. METHODS: This was a single-center, parallel-group, double-blind, controlled randomized clinical trial conducted at Dow University of Health Sciences, Karachi, Pakistan. A total of 105 patients with DH were allocated into three groups for this study. The patients were divided into three groups (Single Bond Universal by 3 M ESPE and Xeno-V + by Dentsply) and the control group containing fluoride varnish (Bifluorid 12 by Voco). Discomfort Interval Scale scores and Schiff Cold Air Sensitivity Scale scores were recorded at baseline, immediately after the intervention, after 01 weeks, and after 01 month. RESULTS: All the materials demonstrated a statistically significant reduction in discomfort and sensitivity (DIS scores p-value 0.01) immediately after 01 week and over a period of 01 month after treatment compared with the baseline scores before application, with no single material proving superior over the one-month observation period. The study also provided insights into dental hygiene practices, with a significant majority using a toothbrush and sensitivity patterns, with cold stimuli being the most common cause of sensitivity. CONCLUSION: The study demonstrates that Single Bond Universal, Xeno V+, and Bifluorid 12 are equally effective in reducing dentin hypersensitivity, with no distinct superiority observed over a one-month period. The findings highlight the potential of fluoride varnishes as a less technique-sensitive and cost-effective option for treating DH, offering valuable insights for future research and clinical practice. TRIAL REGISTRATION: NCT04225247 ( https://clinicaltrials.gov/study/NCT04225247 ), Date of Registration: 13/01/2020. (Retrospectively registered).

Comparison of the effect of propolis and Gluma desensitizer on the management of dentin hypersensitivity: A randomized controlled trial.

OBJECTIVE: To compare the effect of propolis and gluma desensitisers on the management of dentin hypersensitivity. METHODS: The single-blind, randomised controlled trial was conducted at the Department of Operative Dentistry, Dr Ishrat ul Ebad Khan Institute of Oral Health Sciences, Dow University of Health Sciences, Karachi, from October 2020 to September 2021, and comprised patients with dentin hypersensitivity who had pain scores of at least 2 on the visual analogue scale. The teeth were randomised into propolis group A and Gluma group B. Baseline pain scores were assessed using visual analogue scale and Schiff's sensitivity scores and compared with scores immediately after the intervention, and then after one week and one month of the intervention. Data was analysed using SPSS 23. RESULTS: Of the 22 patients, 12(54.5%) were females and 10(45.4%) were males. Of the 80 teeth, there were 40(50%) in each of the 2 groups. Significant reduction was observed in dentin hypersensitivity immediately after the application of the desensitising agents (p<0.05). However, after one month, Gluma was more effective than propolis (p<0.05). CONCLUSIONS: Both Gluma and propolis were found to be effective desensitising agents, but the effectiveness of propolis decreased over one month. Clinical Trial Number: Clinical Trials.gov: NCT04819867.

Evaluation and comparison of the effects of a new paste containing 8% L-Arginine and CaCO3 plus KNO3 on dentinal tubules occlusion and dental sensitivity: a randomized, triple blinded clinical trial study.

BACKGROUND: Dentin hypersensitivity, often occurring after dental treatments or from erosive lesions, is a prevalent patient complaint. This study introduces a paste combining 8% L-arginine, calcium carbonate, and potassium nitrate to evaluate its impact on dentinal tubules occlusion, dentin permeability, and tooth sensitivity. METHODS: Dentin surfaces from 24 third molars (thickness: 2 mm) were divided into two groups of 12. One received the experimental paste, while the other received a placebo without desensitizer. Permeability and sealing ability were assessed through scanning electron microscopy (SEM) and dentin permeability measurement. The pastes' effects on hypersensitivity were then examined in a triple-blind, randomized parallel-armed clinical trial with 16 eligible patients. Sensitivity to cold, touch, and spontaneous stimuli was recorded using the VAS scale at various intervals post-treatment. Statistical analysis was conducted using Shapiro-Wilk, Mann-Whitney U, Friedman, and Wilcoxon tests (α = 0.05). RESULTS: The permeability test demonstrated a significant reduction in dentin permeability in the experimental group (P = 0.002) compared to the control (P = 0.178). SEM images revealed most dentinal tubules in the intervention samples to be occluded. Clinically, both groups showed a significant decrease in the three types of evaluated sensitivity throughout the study. However, no significant difference in sensitivities between the two groups was observed, with the exception of cold sensitivity at three months post-treatment (P = 0.054). CONCLUSION: The innovative desensitizing paste featuring 8% L-arginine, calcium carbonate, and potassium nitrate effectively occluded dentinal tubules and reduced dentin permeability. It mitigated immediate and prolonged dentin hypersensitivity to various stimuli, supporting its potential role in managing dentin hypersensitivity. TRIAL REGISTRATION: http://irct.ir : IRCT20220829055822N1, September 9th, 2022.

Postoperative instructions for silver diamine fluoride therapy: A scoping review of current evidence and practice.

OBJECTIVES: Silver diamine fluoride (SDF) has gained popularity in dentistry as an anti-hypersensitive and anti-caries agent. This study aims to review the postoperative instructions for SDF therapy and examine the evidence supporting these instructions in treating dentine hypersensitivity and caries control. DATA AND SOURCES: Two independent reviewers searched three electronic databases (EMBASE, PubMed, and Web of Science) to identify clinical studies that used SDF to treat dentine hypersensitivity and dental caries. Additionally, they searched Google Chrome for information from manufacturers, the department of health, national dental organisations, authoritative dental organisations, and universities regarding SDF therapy for these conditions. Data on postoperative instructions were extracted, and their impact on the treatment of dentine hypersensitivity and caries control was investigated. STUDY SELECTION: This review included 74 clinical studies, 11 sets of instructions from SDF manufacturers, and six recommendations from national dental organisations, departments of health and universities. Amongst the included records, 50 clinical studies, two manufacturers, and one department of health mentioned postoperative instructions for SDF therapy. The recommendations varied, from suggesting no specific instructions, immediate rinsing, refraining from eating or drinking for 30 to 60 min, and even avoiding brushing until the next day after SDF therapy. Notably, no clinical studies reported the effects of these postoperative instructions on the SDF treatment of dentine hypersensitivity or dental caries. CONCLUSIONS: This scoping review highlights the presence of inconsistent postoperative instructions for SDF therapy in the treatment of dentine hypersensitivity and caries control. Furthermore, there is a lack of evidence supporting the effectiveness of these instructions. CLINICAL SIGNIFICANCE: No evidence supports the postoperative instructions for SDF therapy for managing dentine hypersensitivity and dental caries. Studies are necessary to provide guidance for clinicians using SDF in their clinical practice.

Efficacy of a stannous fluoride dentifrice for relieving dentinal hypersensitivity in Chinese population: an 8-week randomized clinical trial.

OBJECTIVES: To compare the effectiveness of using a 0.454% stannous fluoride-containing dentifrice twice daily in relieving dentinal hypersensitivity (DH) in a Chinese population. MATERIALS AND METHODS: This was a single-centre, randomized, controlled, examiner-blind, three-treatment-arm, parallel-group study in participants with clinically diagnosed DH. Subjects who met inclusion criteria (n = 197) were randomly allocated into 3 groups: test group (n = 66)-using a 0.454% stannous fluoride-containing dentifrice twice daily; positive control group (n = 64)-using a 5.0% calcium sodium phosphosilicate-containing dentifrice twice daily; negative control group (n = 67)-using a 1150 ppm of NaF dentifrice twice daily. Status of DH was assessed at week 4 and week 8 by the same independent examiner. Changes from baseline in Schiff sensitivity score, tactile threshold and Dentine Hypersensitivity Experience Questionnaire (DHEQ) score were analysed using analysis of covariance models. The DHEQ evaluated subject-perceived oral health-related quality of life (OHRQoL). RESULTS: Statistically significant improvements in mean Schiff scores (p < 0.0001 for all products at Weeks 4 and 8), tactile threshold (p < 0.0001 for test and negative control at Weeks 4 and 8: Week 4 p = 0.0040 and Week 8 p < 0.0001 for positive control) and all DHEQ scores (p < 0.01 for all groups) were observed. No statistically significant differences were observed in the adjusted mean between all dentifrices at both timepoints, potentially driven by a placebo effect. Forty-two treatment-emergent adverse events (TEAEs) were reported (n = 32 subjects), with 2 serious AEs (n = 1) in the test group. TEAEs were not considered treatment-related. CONCLUSIONS: All groups demonstrated statistically significant improvements in Schiff score, tactile threshold and OHRQoL. However, due to a possible placebo effect in the negative control, there were no statistically significant differences between the dentifrices. CLINICAL RELEVANCE: This study adds to the growing research exploring why the placebo effect is a common phenomenon in DH studies. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT04950465.

Efficacy of a novel dentifrice containing bioactive glass-ceramic for dentinal hypersensitivity: A double-blind randomized controlled trial in Chinese adults.

OBJECTIVE: To assess the efficacy and safety of a toothpaste containing 7.5 % HX-BGC in combating dentinal hypersensitivity. METHODS: A single-center, randomized, double-blind, three-group parallel-controlled design was employed, with Schiff Index and Yeaple Index as measurement indicators. The study evaluated the effectiveness of HX-BGC toothpaste, NovaMin toothpaste, and a negative control toothpaste without desensitizing agents. Eligible subjects underwent baseline examination after a 2-week washout period, and those meeting inclusion criteria and not meeting exclusion criteria entered the study. Participants were randomly assigned to use one of the three toothpastes. Follow-up examinations were conducted immediately after a single use and at 2, 4, and 6 weeks. Intra-group and inter-group comparisons were made for Schiff and Yeaple indices. Safety of the experimental toothpastes was assessed through participant feedbacks and oral soft tissue examinations. RESULTS: Subjects in the three groups were balanced in terms of age and gender distribution, with no baseline differences in indicators. Immediately after a single application of toothpaste, Yeaple indices increased, and Schiff indices decreased, with no significant differences among the groups. After 2 weeks of continuous use, Yeaple indices increased in all groups, with significant differences observed between the HX-BGC group and the other two groups. Schiff indices decreased in all groups, with the NovaMin group showing significant differences compared to the negative control group. At weeks 4 and 6, both indices in the HX-BGC group and the NovaMin group were significantly better than those in the negative control group, with the HX-BGC group outperforming the NovaMin group in the Yeaple index. No serious adverse reactions related to the study products were observed or reported by any participants. CLINICAL SIGNIFICANCE: This clinical trial confirmed the efficacy of HX-BGC in anti-dentinal hypersensitivity and supported the clinical application of the dentifrice containing HX-BGC. CONCLUSION: Compared to the negative control group, both HX-BGC and NovaMin toothpaste groups demonstrated more significant effects in combating dentinal hypersensitivity. No adverse reactions related to the experimental toothpastes were observed.

Occluding Efficiency of Different Desensitizing Agents and Er,Cr:YSGG Laser on Dentin Tubules.

PURPOSE: This study aimed to evaluate the effects of two desensitizers and the Er,Cr:YSGG laser on human dentin tubules, applied alone or in combination. METHODS: Ninety-six dentin specimens were obtained from extracted third molars and divided into six groups: Group 1: no-treatment (Control); Group 2: nano-hydroxyapatite desensitizer (NhapD); Group 3: NhapD+Er,Cr:YSGG laser (L); Group 4: Er,Cr:YSGG laser (L); Group 5: glutaraldehyde desensitizer (GD); and Group 6: GD+L, respectively. All specimens were evaluated using scanning electron microscopy. The diameter and the number of open dentin tubules, the tubules' occluding ratio, and the mineral coverage area were measured via the Image J software at 2000× magnification. Atomic force microscopy was used to determine the blocking mechanism of desensitizing treatments and the surface morphology of dentin specimens. One-way ANOVA and Tukey tests were used for statistical analysis. RESULTS: The number of open tubules and the mean diameter of tubules for all treatment groups showed statistically significant differences from the control group The NhapD+L group had a significantly lower number of open tubules than the L and GD groups. The NhapD+L and L groups significantly had higher occluding ratios than the other groups. CONCLUSIONS: The present study showed that the Er,Cr:YSGG laser alone was effective in terms of tubule occlusion and also contributed to increasing the occluding ratio of nano-hydroxyapatite. It may be recommended to use the Er,Cr:YSGG laser with nano-hydroxyapatite desensitizers to achieve effective tubule occlusion.

Effects of Propolis-Based Herbal Toothpaste on Dentine Hypersensitivity.

INTRODUCTION: The objective of this in vitro study was to compare the effectiveness of a propolis-based herbal toothpaste with 5% sodium fluoride varnishin obstructing human dentinal tubules; Scanning electron microscopy was utilised to obtain quantitative and qulitative data on tubular obstruction. METHODS: Thirty-nine extracted human premolar teeth were collected. The cementum layer was removed using a water-cooled diamond bur and the smear layer using ethylenediaminetetraacetic acid (EDTA) 17%. Then, the samples were randomly divided into 3 groups (n = 13 each), as follows: group 1: dentin discs exposed to the propolis-based herbal toothpaste (Herbex); group 2: dentin discs exposed to 5% sodium fluoride varnish; and group 3: control. Then, all discs were observed and imaged in 4 non-overlapping fields by an electron microscope at 2000× magnification. The topography and number of open, closed, and semi-closed tubules were counted in all images. The data were analysed using Kruskal-Wallis test, Mann-Whitney U test, and Friedman test. The statistical analysis was performed with SPSS statistic 22.0 software, with a significance level of α = 0.05. RESULTS: In pairwise comparisons of the groups considering the percentage of open, closed, and semi-closed tubules, the difference was not statistically significant between the 5% sodium fluoride varnish and propolis groups in the closed and semi-closed tubules, but it was statistically significant with the control group. Additionally, the percentage of open tubules in the propolis-based herbal toothpaste group was significantly lower than in the 5% sodium fluoride varnish and control group. CONCLUSIONS: Both propolis-based herbal toothpaste and 5% sodium fluoride varnish is effective in blocking human dentin tubules to various extents.

Dentine tubule occlusion effect of hydrolyzed casein in a bioactive glass-based dental desensitizing gel.

OBJECTIVES: The effectiveness of three different groups of polyethylene glycol (PEG)-based gels containing powders on dentin hypersensitivity (DH) treatment were assessed and compared with Actimins® as commercial reference group. METHODS: Hydroxyapatite nanorods (nHA) and sol-gel-derived 45S5 bioglass (SGD 45S5) powders were synthesized through hydrothermal and sol-gel methods, respectively. First, 25 demineralized dentin disks were divided into five groups. Then, the prepared gels based on 45S5 bioglass with and without hydrolyzed casein (HC) as experimental, nHA gel and Actimins® as positive and commercial reference groups were applied twice a day on disks by a micro applicator. To mimic the oral environment, treated disks were immersed in artificial saliva in a water bath at 37 °C for 7 days. However, in the negative control group, no agent was applied on the samples. FE-SEM, EDS, AFM, and XRD were performed to assess tubule occlusion. One-way ANOVA test was used for statistical analysis and p*<0.05 was set as the significance level. RESULTS: The nHA with an average aspect ratio of 2.77 and the SGD 45S5 powders with a polygonal morphology and the average size of 48.64±11.38 µm were synthesized. After treatment, tubule occlusion in HC-SGD 45S5 and nHA gels were shown to be higher than other groups. The root mean square roughness (Rrms) of the above-mentioned gels showed to be 121.54±9.25 nm, and 312.6 ± 9 nm, respectively. CONCLUSION: The nHA containing group exhibited the highest tubule occlusion efficiency (i.e., tubule diameter of 0.92±0.32 µm) with a superior mineral precipitation. HC as a novel material demonstrates to be potentially beneficial in DH treatment. CLINICAL SIGNIFICANCE: DH as a common issue may be reduced or eliminated by occlusion of patent dentinal tubules. There are various types of desensitizing agents capable of controlling the DH by the occlusion of patent dentinal tubules. The desensitizing gels developed in this study showed to be promising for clinical and home-use applications.

Treating hypersensitivity in older adults with silver diamine fluoride: A randomised clinical trial.

OBJECTIVE: This study aimed to evaluate the desensitizing effect of topically applied 38% silver diamine fluoride (SDF) solution on the exposed root surface of hypersensitive teeth in older adults. METHOD: This double-blind randomised clinical trial recruited healthy older adults with dentine hypersensitivity. A trained examiner tested the most hypersensitive tooth root surface with a blast of compressed cold air from a three-in-one syringe. The participants gave a sensitivity score (SS) in visual analogue scale from 0 (no pain) to 10 (agonizing) at the baseline visit. Then, they received 38% SDF or 5% potassium nitrate solution (control) as intervention on the root surface. After the intervention, they received a compressed cold air test and reported the SS again. The compressed cold air test followed by intervention was repeated at 4- and 8-week follow ups. The primary outcome was the reduction in SS at 8-week follow-up with reference to the SS at baseline before intervention. Shapiro-Wilk and Mann-Whitney U tests were performed for data analysis following a normality test of SS. RESULTS: This trial recruited 148 participants, and 139 (94%) participants completed the trial. The median percentage reductions in SS in the SDF and potassium nitrate groups were 60% and 50%, respectively (p < 0.001). CONCLUSION: According to the results, 38% SDF solution reduced hypersensitivity on the exposed root surface of older adults. In addition, 38% SDF was more effective than 5% potassium nitrate solution to reduce hypersensitivity on the exposed root surface of older adults. CLINICAL SIGNIFICANCE: Dentin hypersensitivity is common amongst older adults and negatively affects their quality of life. To date, there is no gold standard professionally applied desensitizing therapy in treating hypersensitivity. Evidence from this clinical trial could aid clinical practice and improve oral health in older adults. TRIAL REGISTRATION: This study was registered at ClinicalTrials.gov (NCT05392868).

A randomized clinical trial for comparing the efficacy of desensitizing toothpastes on the relief of dentin hypersensitivity.

The 4-week double-blind clinical trial to manage dentin hypersensitivity (DH) using different desensitizing toothpastes was conducted. 53 participants with DH were enrolled in this trial. The participants were randomized into 3 groups: Group N; no active ingredient-containing toothpaste (Pleasia fluoride-free), Group SC; a toothpaste containing strontium chloride (Sensodyne Original), and Group TP; a toothpaste containing tricalcium phosphate (Vussen S). They were instructed to brush their teeth manually for 3 min, 3 times per day for 4 weeks with the allocated toothpastes, and were assessed at baseline (0), 2, and 4 weeks, respectively. Schiff sensitivity score was recorded to 3 different stimuli (air-blast, cold, and acid) at each assessment. Overall DH was also assessed using a visual analog scale (VAS). The longer participants used the toothpastes, the greater reduction in DH in all groups to the three stimuli. Group TP demonstrated significant reduction of DH compared to group N for air-blast and cold stimuli. Group TP showed significantly lower VAS than group N and SC. Tricalcium phosphate containing toothpaste used in this trial was most useful to reduce DH. It can be one of the treatment options that alleviate DH.

Comparative efficacy of self-administered dentifrices for the management of dentine hypersensitivity - A systematic review and network meta-analysis.

OBJECTIVES: This systematic review with network meta-analysis synthesises available randomised controlled trials evidence concerning efficacy of self-administered dentifrices for management of dentine hypersensitivity (DH) pain. STUDY SELECTION: Following systematic review registration (CRD42019154064), three data bases (MEDLINE, Embase, CENTRAL) were searched to December 2022 for parallel randomised controlled trials conducted in adults diagnosed with DH, using at least two recognised stimuli, assessing the short-term efficacy of home-use dentifrice treatment in reducing pain. Thirty-two studies and 4,638 participants were included. A Network meta-analysis (NMA) approach was used to compare relative effectiveness between interventions. CONCLUSIONS: Twice daily application of self-applied dentifrice containing formulations of stannous, potassium +/- stannous, or arginine can be recommended for the reduction of dentine hypersensitivity pain. There is a need for standardised methodology guideline development to improve the conduct, analysis and reporting of DH clinical studies. CLINICAL RELEVANCE: This is the first comprehensive NMA to be performed, that follows guidelines for conduct of DH trials to determine the efficacy of self-applied dentifrices for the management of dentine hypersensitivity. Indirect comparisons can be made between formulations that have not been compared to one another in randomised controlled trials.

Clinical Efficacy of Mouthwashes with Potassium Salts in the Treatment of Dentinal Hypersensitivity: A Systematic Review and Meta-analysis.

AIM: This systematic review and meta-analysis evaluated whether the home use of mouthwashes containing potassium salts is effective in reducing and controlling dentin hypersensitivity (DH). METHODS AND MATERIALS: This study is reported according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) checklist and was registered in PROSPERO (CRD42021228410). Randomized clinical trials evaluating the use of mouthwashes containing potassium salt for daily household mouthwash for at least four weeks to reduce DH compared with a control mouthwash were selected, with no limitation on year of publication. Electronic research was carried out in PubMed/MEDLINE, Scopus, Web of Science, and Cochrane Library by two independent researchers. One hundred thirty-three articles were obtained, and nine were selected according to the inclusion criteria. RESULTS: The selected studies evaluated DH through tests of sensitivity to tactile and evaporative stimuli and showed that, for the tactile stimulus, there were no baseline differences between groups (p=0.12; mean difference: -0.33; confidence intervals [CI]: -0.73 to 0.08). However, there were significant differences after two weeks of use (p=0.00001; mean difference: 4.67; CI: 4.53 to 4.81), after four weeks (p=0.00001; mean difference: 13.29; CI: 13.03 to 13.55), and after eight weeks (p=0.00001; mean difference: 8.88; CI: 5.73 to 12.02) favoring the experimental group. The results of the evaporative test showed no differences in the baseline assessment between the two groups (p=0.50; mean difference: -0.02; CI: -0.09 to 0.04), but after four weeks (p=0.00001; mean difference: -0.32; CI: -0.44 to -0.20), and eight weeks of use (p=0.00001; mean difference: -0.42; CI: -0.57 to -0.27) there were differences favoring the experimental group. The incidence of side effects showed no differences between the two groups (p=0.89; mean difference: 1.03; CI: 0.67 to 1.58). CONCLUSION: The daily use of mouthwashes containing potassium salt is effective in the treatment of dentinal hypersensitivity, as a complementary step to brushing at least twice a day for two weeks, four weeks, and up to eight weeks, without presenting side effects.

In vitro dentin permeability and tubule occlusion of experimental in-office desensitizing materials.

OBJECTIVES: This study investigates the dentin permeability (by hydraulic conductance) and tubule occlusion (by confocal and scanning electron microscopies) of in-office desensitizing materials. MATERIALS AND METHODS: Bovine dentin blocks were immersed in EDTA to open dentinal tubules. Placebo varnish (PLA), fluoride varnish (FLU), NaF 5% + 5% nanoparticulate sodium trimetaphosphate varnish (TMP), universal adhesive system (SBU), S-PRG filler varnish (SPRG), Biosilicate (BIOS), and amelotin (AMTN) solution were the materials tested. After application, the specimens underwent an erosive-abrasive challenge. Dentin permeability was evaluated at T0 (initial), T1 (after treatment), and T2 (after challenge). Confocal and scanning electron microscopy (SEM) were used to evaluate, respectively, length and number of dentinal tubule occlusions and opened dentinal tubules, after challenge. Permeability and SEM data were analyzed by two-way repeated measures ANOVA and Tukey's tests. Confocal data were analyzed by one-way ANOVA, Tukey's test, and Kruskal-Wallis and Dunn's tests. Spearman and Pearson's correlation tests were also used. Significance level was set at 5%. RESULTS: At T1, the AMTN group showed the lowest permeability value, following the increasing order at T2: AMTN = SBU < BIOS = SPRG < TMP < FLU < PLA. The SBU group had the highest value of occluded dentinal tubule length. The AMTN group presented more occluded dentinal tubules compared to PLA and FLU. AMTN and SBU had the lowest values of opened dentin tubules. Results showed a negative correlation between the analyses. CONCLUSION: The SBU and AMTN solution were more effective in reducing dentin permeability by occluding dentin tubules. CLINICAL RELEVANCE: All materials reduced permeability after challenge, except fluoride varnish.

Clinical trials evaluating desensitising agents. Some design and analysis issues.

INTRODUCTION: The purpose of this short communication is to draw attention to an efficient design for trials to evaluate desensitising agents, and an appropriate statistical analysis. METHODS: Two recent sensitivity trials conducted by the Bristol Dental School Clinical Trials Group are reviewed. RESULTS: The methodology used was effective to establish efficacy of the products evaluated. CONCLUSIONS: This methodology is recommended for wider use. CLINICAL SIGNIFICANCE: Effective clinical trial methodology enables establishment of efficacy of desensitising products leading to patient benefit.

Effectiveness and cytotoxicity of two desensitizing agents: a dentin permeability measurement and dentin barrier testing in vitro study.

BACKGROUND: When evaluating the efficacy and safety of various desensitizing products in vitro, their mechanism of action and clinical utility should be considered during test model selection. This study aimed to evaluate the effects of two desensitizers, an in-office use material and an at-home use material, on dentin specimen permeability, and their dentin barrier cytotoxicity with appropriate test models. METHODS: Two materials, GLUMA desensitizer (GLU) containing glutaraldehyde and remineralizing and desensitizing gel (RD) containing sodium fluoride and fumed silica, were selected. Human dentin specimens were divided into three groups (n = 6): in groups 1 and 2, GLU was applied, and in group 3, RD was applied and immersed in artificial saliva (AS) for 24 h. Dentin specimen permeability before and after each treatment/post-treatment was measured using a hydraulic device under a pressure of 20 cm H2O. The perfusion fluid was deionized water, except in group 2 where 2% bovine serum albumin (BSA) was used. The representative specimens before and after treatment from each group were investigated using scanning electron microscopy. To measure cytotoxicity, test materials were applied to the occlusal surfaces of human dentin disks under which three-dimensional cell scaffolds were placed. After 24-h contact within the test device, cell viability was measured via 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays. RESULTS: GLU significantly reduced the dentin permeability and occluded the dentinal tubules when 2% BSA was used as perfusion fluid. RD significantly reduced dentin permeability and occluded the tubules, but permeability rebounded after AS immersion. GLU significantly decreased cell viability, but RD was non-cytotoxic. CONCLUSIONS: In vitro GLU application induced effective dentinal tubule occlusion only following the introduction of simulated dentinal fluid. RD provided effective tubule occlusion, but its full remineralization potential was not realized after a short period of immersion in AS. GLU may harm the pulp, whereas RD is sufficiently biocompatible.

Assessment of the Ability of Desensitizing and Conventional Mouth Rinses to Promote Dentin Tubule Occlusion.

This study aimed to evaluate the effect of desensitizing and conventional mouth rinses on dentin tubule occlusion. Dentin hypersensitivity was simulated by EDTA application for five minutes. The specimens were randomly allocated into the following groups: desensitizing mouth rinses (Colgate Sensitive, Elmex Sensitive Professional, Listerine Advanced Defense Sensitive, Sensodyne Cool Mint); conventional mouth rinses (Colgate Plax, Elmex Caries Protection, Listerine Anticaries, Sensodyne Pronamel); a negative control (C-: distilled water); and Clinpro XT Varnish was the positive control (C+). Subsequently, the specimens were submitted to an erosive or abrasive challenge (performed separately) and to an erosive/abrasive cycling for five days (n=10 for each challenge). After treatment, challenges, and cycling, the specimens were analyzed in an environmental scanning electron microscope to verify the number of open dentin tubules (ODTs), counted by using Image J software (National Institutes of Health, Bethesda, MD, USA). Data were analyzed by the Kruskal-Wallis, Friedman and Dunn tests, with Bonferroni correction (α=0.05). Groups did not differ at baseline (p>0.05). At the post-treatment, erosion and abrasion stages, C+ was the only group that showed a reduction in ODTs compared to C-(p<0.05). In the other groups, numbers did not differ significantly from C- (p>0.05). After cycling, none of the groups exhibited significant reduction in ODTs other than C- (p>0.05); however, C+, Listerine Anticaries, and Colgate Plax had a lower number of ODTs than Listerine Sensitive and Sensodyne Pronamel. No mouth rinse was able to promote significant occlusion of the dentin tubules after treatment and the challenges. C+ was the only product that effectively promoted tubular occlusion, but this effect did not withstand several erosive and abrasive challenges.

Occlusion effects of bioactive glass and hydroxyapatite on dentinal tubules: a systematic review.

OBJECTIVE: Bioactive glass and hydroxyapatite are biocompatible materials used as an adjunct to various dental materials. The present study aimed to evaluate the occlusion effects of bioactive glasses and hydroxyapatite on dental tubules. MATERIALS AND METHODS: We searched the PubMed/Medline, Embase, and Web of Science databases for the relevant records. The methodological quality of the studies was assessed by an accepted quality assessment tool. RESULTS: From the electronic databases, 372 articles were retrieved. After evaluating the records, 35 in vitro studies were included. The studies revealed a low risk of bias. The primary outcomes from bioactive glass studies demonstrated the potential efficacy of both bioactive glass and hydroxyapatite in dentin tubule occlusion compared to the control. CONCLUSION: The current systematic review showed that bioactive glass and hydroxyapatite could effectively occlude the dentinal tubules. Thus, desensitizing agents containing bioactive glass and hydroxyapatite can be used to manage dentin hypersensitivity (DH). However, long-term follow-up clinical trials are required in the future before definitive recommendations can be made. CLINICAL RELEVANCE: This work achieved a satisfactorily systematic review for assessing desensitizing agents containing bioactive glass and hydroxyapatite in dentine hypersensitivity treatments recommended for clinical practice and research.

Photobiomodulation therapy and 3% potassium nitrate gel as treatment of cervical dentin hypersensitivity: a randomized clinical trial.

OBJECTIVES: This randomized controlled trial aimed to evaluate different protocols for dentin hypersensitivity treatment with low-power lasers and desensitizing agents, and the association between low-power lasers and desensitizing agents. MATERIALS AND METHODS: Fifty-four patients (303 teeth) were randomly allocated to three groups: G1, 3% nitrate potassium gel, UltraEZ (n = 17); G2, photobiomodulation therapy (PBM) with a low-level infrared laser (n = 17), 100 mW, spot size of 0.028 cm2, and dose of 1 J per point; and G3, nitrate potassium + PBM (n = 20). Treatments were applied to the buccal cervical region at intervals of 72 h, and all protocols were performed in three sessions. The patients' response to evaporative stimuli was rated using the visual analog scale (VAS). Re-evaluations were performed immediately after each application and 1 week, 1 month, and 3 months after treatment. A two-way repeated measures test and Tukey's post hoc test were used for multiple comparisons (α = 5%). RESULTS: There was a reduction in pain levels at the end of treatment in all groups. There were no significant differences in VAS score changes between the groups immediately after treatment and after the third month, compared to the baseline (p > 0.05). CONCLUSION: Under the limitations of this in vivo study, the proposed three-session protocol was effective in reducing dentin hypersensitivity after 3 months, regardless of the desensitization mechanism used. Conservative and long-term protocols are interesting for the control of pain caused by dentin hypersensitivity. CLINICAL RELEVANCE: The increase in cervical dentin hypersensitivity prevalence warrants easy-to-apply and long-lasting desensitizing protocols for pain control.

Experimental pastes containing niobophosphate and 45S5 bioactive glasses for treatment of dentin hypersensitivity: dentin permeability and tubule obliteration.

OBJECTIVES: This study tested the ability of bioactive pastes containing niobophosphate and 45S5 glasses to reduce dentin permeability and to obliterate dentinal tubules, as a mean of reducing human dentin hypersensitivity. MATERIALS AND METHODS: Experimental pastes with concentrations of 10, 20, and 30 wt% of two bioactive glasses (45S5 or niobophosphate [NbG]) were formulated. A paste without bioactive glass (placebo) and a commercial paste (Nano P, FGM) were used as controls. Forty dentin disc specimens were obtained from caries-free extracted third human molars and divided in 8 groups (n = 5). Percentage of permeability (%Lp) was assessed in a dental permeability machine considering hydraulic conductance, immediately after pastes application and at day 7, day 14, and day 21. The precipitates formed on the surface of the dentin discs (and dentinal tubules) were analyzed by SEM/EDS and micro-Raman spectra. Data of dentin permeability (%) 2-way repeated-measures (ANOVA) and Holm-Sidak post-tests (α = 0.05). Dentinal tubule obliteration was visually (and elemental) evaluated and descriptively reported. RESULTS: The experimental bioactive glass pastes containing NbG and 45S5, regardless of the concentration, reduced dentin permeability in comparison with pastes without bioactive glasses (P < 0.05). The formulated placebo and commercial paste did not reduce permeability over time (P < 0.05). SEM/EDS and micro-Raman analyses showed that both type of bioactive pastes (NbG or 45S5-based) presented mineral precipitates obliterating the dentinal tubules at day 21. NbG seems to offer a better initial effect than 45S5, while at 21 days there is no difference between both glasses. CONCLUSION: Experimental bioactive pastes containing NbG and 45S5 (at concentrations of 10%, 20%, or 30%) have potential to reduce dentin permeability (over time) in comparison with pastes without bioactive glasses; and this occurs on behalf of obliteration of dentinal tubules by microparticle and precipitate formation. CLINICAL RELEVANCE: Bioactive pastes containing NbG and 45S5 may benefit patients presenting dentin hypersensitivity, because these pastes can start acting fast after application and maintain their action up to 21 days.