Dentine hypersensitivity — an enigma? a review of terminology, mechanisms, aetiology and management

The Synergistic Effect of Ozonated Oil and Desensitising Toothpaste on Dentinal Tubule Occlusion: An In Vitro Study

Introduction Dentin hypersensitivity (DH) is the most common problem encountered by clinicians. It can be managed either by blocking neural activities or by occluding tubules. Ozonated oil facilitates the simple passage of desensitizing agents into dentinal tubules. Aim This study aimed to evaluate the effect of ozonated oil on dentinal tubule occlusion before and after the application of desensitizing toothpaste. Materials and methods The study was carried out in Kalinga Institute of Dental Sciences, KIIT (Deemed to be University), Bhubaneswar, India. The sample size of the study was 80. The first group contained specimens for control. The second group comprised specimens treated with ozonated oil. The third group comprised specimens being treated with a desensitizing agent. The fourth group contained specimens treated with both the desensitizing agent and ozonated oil. The specimens then received an acid challenge. The specimens were observed under a scanning electron microscope (SEM) before any therapy, after the application of the therapeutic agents and after the 37.5% ortho-phosphoric acid challenge. Results Inferential statistics to compare between the groups was calculated using one-way analysis of variance (ANOVA) statistics. Post-hoc Tukey's honestly significant difference (HSD) was performed to compare the groups. The mean scores of the partial tubular occlusion of Group 1, Group 2, Group 3 and Group 4 before the acid challenge were 0.035, 0.691, 0.564 and 0.368, respectively. The maximum score was obtained in the case of Group 2, which was statistically significant. The mean scores for partial tubule occlusion after the acid challenge for Group 1, Group 2, Group 3 and Group 4 were 0.055, 0.531, 0.733 and 0.142, respectively. There was evidence of maximum partial tubule occlusion after the acid treatment in the case of Group 3. The mean scores of Group 1, Group 2, Group 3 and Group 4 before the acid challenge were 0.019, 0.309, 0.442 and 0.609, respectively. The maximum score was obtained in the case of Group 4, implying a greater number of total tubular occlusions before the acid challenge. The mean scores of the total tubular occlusions after the acid challenge for Group 1, Group 2, Group 3 and Group 4 were 0.047, 0.465, 0.272 and 0.890, respectively. There was evidence of maximum tubule occlusion in the case of Group 4, which was statistically significant. Conclusion Overall, the application of a desensitizing toothpaste with ozonated oil holds promise as a potentially more effective treatment approach for DH. Further research and clinical studies may be needed to fully validate its efficacy and safety in dental practice.

Penetration and durability of CPP-ACP paste and sodium fluoride varnish as desensitizing agents: An in vitro comparison

Background

This study aimed to investigate and compare the penetration and durability of two dentin desensitizers, sodium fluoride varnish and casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) paste, using electron microscopy.

Methods

The study was performed on 60 dentin specimens prepared from extracted human premolars. After applying 17% EDTA to remove the smear layer, the specimens were divided into two groups. MI Paste and Bi-fluoride varnish were applied to the specimens. Microscopic images of 20 samples were obtained immediately. Twenty other samples were accessed after 15 days, and the other 20 were accessed after 30 days of toothbrushing and thermal cycling. Both surface and longitudinal cross-sectional images (after sample fracture) were studied. Data were analyzed with two-way ANOVA and Mann-Whitney U test at a significance level of P<0.05.

Results

The mean depth of material penetration was significantly time-dependent and fluctuated in both groups. There was a significant difference between the mean level of plugs between 0, 15, and 30 days (P<0.001). Penetration increased with time for the MI Paste group, while in the Bi-fluoride group, the increase was significant at 15 and 30 days than immediately after application. The mean thickness of the plugs was significantly different at the three time periods, and MI Paste showed a sudden decrease in plug thickness after 15 days.

Conclusion

Immediately after application, Bi-fluoride occluded dentinal tubules more effectively, and its durability after abrasion and thermal fatigue were higher than MI Paste.

The prevalence and predictive factors of dentine hypersensitivity among adults in Turkey

AIM

This study sought to determine the prevalence of dentine hypersensitivity (DH) among adults in Turkey. Also, to ascertain the association between DH and both etiological predictors and demographic patient characteristics.

MATERIAL METHOD

Using a questionnaire and thermal and evaporative tests, 259 women and 209 men in the age range of 18 to 72 were analyzed. Individually, a clinical evaluation of DH signs was conducted. The DMFT index, gingival index, and gingival bleeding were reported for each subject. The gingival recession and tooth wear of sensitive teeth were also evaluated. Pearson Chi-square test was used to compare categorical data. Logistic Regression Analysis was used to examine the risk factors of DH. Data with dependent categorical variables were compared using the McNemar-Browker test. The significance level was p < 0.05.

RESULTS

The average age of the population was 35.6 years. In the present study, a total of 12,048 teeth were analyzed. 1755 had thermal hypersensitivity (14.57%), while 470 experienced evaporative hypersensitivity (3.9%). The incisors were the teeth most impacted by DH, whereas the molars were the least affected. Exposure to cold air and sweet foods, gingival recession, and the presence of noncarious cervical lesions were all strongly linked to DH (Logistic regression analysis, p < 0.05). The cold stimulus increases sensitivity more than the evaporation stimulus.

CONCLUSION

Significant risk factors for both thermal and evaporative DH include cold air, consumption of sweet food, presence of noncarious cervical lesions, and gingival recession. More epidemiological research in this area is still required to fully characterize the risk factors and implement the most effective preventive interventions.

Biomimetic Dentin Repair: Amelogenin-Derived Peptide Guides Occlusion and Peritubular Mineralization of Human Teeth

Exposure of dentin tubules due to loss of protective enamel (crown) and cementum (root) tissues as a result of erosion, mechanical wear, gingival recession, etc. has been the leading causes of dentin hypersensitivity. Despite being a widespread ailment, no permanent solution exists to address this oral condition. Current treatments are designed to alleviate the pain by either using desensitizers or blocking dentin tubules by deposition of minerals or solid precipitates, which often have short-lived effects. Reproducing an integrated mineral layer that occludes exposed dentin with concomitant peritubular mineralization is essential to reestablish the structural and mechanical integrity of the tooth with long-term durability. Here, we describe a biomimetic treatment that promotes dentin repair using a mineralization-directing peptide, sADP5, derived from amelogenin. The occlusion was achieved through a layer-by-layer peptide-guided remineralization process that forms an infiltrating mineral layer on dentin. The structure, composition, and nanomechanical properties of the remineralized dentin were analyzed by cross-sectional scanning electron microscopy imaging, energy dispersive X-ray spectroscopy, and nanomechanical testing. The elemental analysis provided calcium and phosphate compositions that are similar to those in hydroxyapatite. The measured average hardness and reduced elastic modulus values for the mineral layer were significantly higher than those of the demineralized and sound human dentin. The structural integration of the new mineral and underlying dentin was confirmed by thermal aging demonstrating no physical separation. These results suggest that a structurally robust and mechanically durable interface is formed between the interpenetrating mineral layer and underlying dentin that can withstand long-term mechanical and thermal stresses naturally experienced in the oral environment. The peptide-guided remineralization procedure described herein could provide a foundation for the development of highly effective oral care products leading to novel biomimetic treatments for a wide range of demineralization-related ailments and, in particular, offers a potent long-term solution for dentin hypersensitivity.

Comparative Evaluation of Abrasiveness among Three Dentifrices: An In Vitro Study

Aim

A lot of herbal and medicated toothpastes having natural and antisensitivity properties are creating niches for themselves in the market. However, toothpaste containing high content of abrasives can be harmful to the teeth. The present in vitro study was conducted to assess the abrasiveness of three commercially available dentifrices on human-extracted anterior teeth on sound and demineralized enamel.

Materials and methods

A total of 42 freshly extracted teeth were mounted on acrylic resin and randomly divided into three groups (group I, Colgate; II, Glister; and III, Dant Kanti). Each group consisted of one test tooth (partially) and one control tooth (completely) covered with nail varnish. The study had two phases. Phase 1-baseline average roughness (Ra) value was assessed with a profilometer of all the samples. Phase 2-further, teeth were immersed in the demineralizing solution for 4 days to allow the formation of an artificial carious lesion. Tooth brushing was performed by a customized automated toothbrushing model on all the teeth for 28 days. Ra value was again evaluated with Profilometer.

Result

Data were analyzed, and a statistically significant result was observed with demineralized teeth in all three groups (p = 0.005). The intragroup comparison showed a significant difference with demineralized teeth of Colgate and Dant Kanti, (p =0.018) and (p =0.027), respectively. However, there was no significant difference in demineralized teeth of glister and sound teeth of all three groups.

Conclusion

Glister was found to be the least abrasive of all three toothpastes, followed by Dant Kanti and Colgate.

Clinical relevance

The particle size of the ingredients used in manufacturing toothpaste can lead to abrasion of the teeth.This, in combination with the hard bristles, can cause more harm to the teeth than good. The current study has compared the abrasive potential of three commercially available kinds of toothpaste. Hence daily use of these commercially available dental products should be used cautiously.

How to cite this article

Priyam S, Sankeshwari R, Jalihal S, et al. Comparative Evaluation of Abrasiveness among Three Dentifrices: An In Vitro Study. Int J Clin Pediatr Dent 2023;16(2):264-269.

Comparative evaluation of diode laser alone and in combination with desensitizing toothpaste in occlusion of dentinal tubules - A SEM study

Background

In regular dental practice, dentinal hypersensitivity is a common oral condition affecting the adult population. Although a variety of treatment procedures are available, there is no single method that proved to be potent in eliminating dentine hypersensitivity and providing patients with complete relief. Hence the present study performed to estimate the occlusion of dentinal tubules using a diode laser alone and in combination with various desensitizing toothpaste, using the scanning electron microscope.

Materials and methods

This in-vitro study consisted of five groups wherein cervical cavities were prepared on the extracted teeth followed by the application of 17% EDTA. The cavities were then treated with Novamin toothpaste, pro-arginine toothpaste, diode laser, and in combinations respectively. Then SEM analysis was done and the results obtained were statistically analyzed using tukey's multiple post hoc analysis for intra and inter group comparisons.

Results

The groups which were treated with a combination of diode laser and the desensitizing agent showed statistically significant (P < 0.05) better dentinal tubule occlusion than other groups.

Conclusion

The use of a diode laser has an added benefit in treating dentinal tubule occlusion when compared to desensitizing kinds of toothpaste.

Mechanosensitive Piezo1 and Piezo2 ion channels in craniofacial development and dentistry: Recent advances and prospects

Mechanical forces play important roles in many biological processes and there is increasing interest and understanding of these roles. Mechanotransduction is the process by which mechanical stimuli are converted to biochemical signals through specific mechanisms, and this results in the activation of downstream signaling pathways with specific effects on cell behaviors. This review systematically summarizes the current understanding of the mechanosensitive Piezo1 and Piezo2 ion channels in craniofacial bone, tooth, and periodontal tissue, presenting the latest relevant evidence with implications for potential treatments and managements of dental and orofacial diseases and deformities. The mechanosensitive ion channels Piezo1 and Piezo2 are widely expressed in various cells and tissues and have essential functions in mechanosensation and mechanotransduction. These channels play an active role in many physiological and pathological processes, such as growth and development, mechano-stimulated bone homeostasis and the mediation of inflammatory responses. Emerging evidence indicates the expression of Piezo1 and Piezo2 in bone, dental tissues and dental tissue-derived stem cells and suggests that they function in dental sensation transduction, dentin mineralization and periodontal bone remodeling and modulate orthodontic tooth movement.

ISP Good Clinical Practice Recommendations for the management of Dentin Hypersensitivity

Dentin hypersensitivity (DH) is a rising concern in clinical dentistry that causes pain and discomfort and negatively affects the quality of life of patients. Indian Society of Periodontology conducted a nationwide survey, involving 3000 dentists in December 2020, which revealed significant knowledge gaps regarding DH, viz., under-diagnosis, incorrect differential diagnosis, and treatment strategies/recommendations for the management of DH patients in daily clinical practice. The current paper has been envisioned and conceptualized to update the practicing Indian dentists regarding the so-called enigma of dentistry “Dentin Hypersensitivity,” based on the best available contemporary evidence. An expert panel was constituted comprising 30 subject experts from across the country, which after extensive literature review and group discussions formulated these recommendations. The panel advocated routine screening of all dentate patients for exposed dentin areas and DH to avoid under-diagnosis of the condition and suggested an early preventive management. Consensus guidelines/recommendations for the use of desensitizing agents (DAs) at home, including the use of herbal agents, are also provided within the backdrop of the Indian context. The guidelines recommend that active management of DH shall be accomplished by a combination of at home and in-office therapies, starting with the simplest and cost-effective home use of desensitizing toothpastes. A diagnostic decision tree and a flowchart for application in daily practice are designed to manage the patients suffering from DH or presenting with exposed dentin areas in dentition. Various treatment methods to manage DH have been discussed in the paper, including the insights from previously published treatment guidelines. Further, a novel system of classification of DH patients based on specific case definitions has been developed for the first time. Explicit charts regarding the available treatment options and the chronology of institution of the agent, for the management in different case categories of DH, have been provided for quick reference. The management strategy takes into account a decision algorithm based on hierarchy of complexity of treatment options and intends to improve the quality of life of the patient by long-term maintenance with an innovatively defined triple C's or 3Cs approach.

Robot and mechanical testing of a specialist manual toothbrush for cleaning efficacy and improved force control

Background

Toothbrushes require flexibility to access all dental surfaces and remove plaque effectively, but they should also aim to prevent or limit overbrushing and consequent damage to teeth and gums. In two studies, the physical properties and cleaning performance of specialist test toothbrushes with flexible necks were compared to a reference rigid-necked toothbrush.

Methods

In Study 1, a universal testing machine (Instron E 10,000) with a specially designed setup was used to test the deflection behaviour of toothbrush head and neck. Untufted toothbrushes were fixed in a custom holder and force was applied to the head while the deflection was measured. In Study 2, one control and five test toothbrushes were assessed using a robot system to simulate the cleaning of artificial plaque from defined surfaces of artificial replicated human teeth in a model oral cavity (typodonts).

Results

Study 1 showed that the flexible-neck toothbrush deflected 2 to 2.5 times more than the rigid-neck reference toothbrush when same force was applied to the toothbrush head. Study 2 revealed that all five test toothbrushes showed statistically superior simulated plaque removal to the reference toothbrush. This superiority was observed for all test toothbrushes employing horizontal and rotating brushing action (all p = 0.001) but only three of the five toothbrushes when vertical brushing was employed (all p = 0.001). Cleaning efficacy of the test toothbrushes was demonstrated both interdentally and at the gumline locations. The Complete Protection toothbrush showed the most effective cleaning performance followed by the Repair and Protect and Rapid Relief toothbrushes.

Conclusion

The addition of a flexible-neck component to the toothbrush designs helped to reduce stiffness and may allow more effective cleaning compared to rigid designs with controlled force distribution on the teeth and gums. This may help to provide plaque control at all potential risk areas in an in vitro robot model and could support good oral hygiene in-use.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12903-022-02211-4.

Evaluation of Dentin Tubule Plugging Efficiencies and Effects on Dentin Surface Roughness of Dentin Desensitizing Agents, the Er,Cr:YSGG Laser, and Their Combination After Erosion-Abrasion Cycles: An In Vitro Study

OBJECTIVES

The purposes of this in vitro study were to evaluate the tubule plugging efficiencies and effects on the surface roughness of dentin of different dentin desensitizing agents (DDAs; Teethmate Desensitizer, Kuraray; Gluma Desensitizer, Kulzer; Clinpro White Varnish, 3M ESPE; Enamelast, Ultradent) and the Er,Cr:YSGG laser (Biolase, Waterlase), both alone and in combination with DDAs, after application and after an erosion-abrasion cycle.

METHODS AND MATERIALS

For surface roughness examinations, superficial buccal dentin specimens were divided into 10 groups: the control, Teethmate Desensitizer, Gluma Desensitizer, Enamelast, Clipro White Varnish, Er,Cr:YSGG Laser, Teethmate Desensitizer-Laser, Gluma Desensitizer-Laser, and Enamelast-Laser, and Clinpro White Varnish-Laser groups. Profilometric analyses and scanning electron microscopy (SEM) examinations were performed after applications and after a 5-day erosive-abrasive cycle. For the statistical analysis of surface roughness measurements, 2-way analysis of variance (ANOVA), 1-way ANOVA, and Tukey post hoc test were used.

RESULTS

Among the treatments, only DDAs alone did not cause increase in surface roughness after application. All of the laser applications increased the surface roughness of dentin, and after the erosion-abrasion cycle, all of the test groups had increased surface roughness. However, SEM images showed that morphological changes were less frequently observed in all of the experimental groups than in the control group. In addition, all of the laser-DDA combinations had stronger tubule occlusion effects than did DDAs alone, even after erosion-abrasion.

CONCLUSIONS

All of the test treatments showed protective effects on dentin surfaces against the negative effects of erosion-abrasion. The addition of the laser to DDA applications increased tubular plugging efficiencies of DDAs, and the tubule plugs of the combination treatments were resistant to the erosion-abrasion cycle.

The prevalence, clinical features, and related factors of dentin hypersensitivity in the Turkish population

OBJECTIVES

The purpose of this study was to identify the prevalence and predisposing and etiologic factors of dentin hypersensitivity (DH), as well as the demographic characteristics of patients.

MATERIALS AND METHODS

The 1210 patients were examined. The research was based on a two-step investigation: questionnaire and clinical examination. DH was evaluated by the response of the patient to tactile and air-blast stimuli. Loss of attachment and gingival recession of sensitive teeth was measured on the buccal and lingual surfaces. Also, the tooth wear of sensitive teeth was graded on the buccal and lingual surfaces. Comparisons of nonnormally distributed continuous variables were performed using the Mann-Whitney U test and Kruskal-Wallis one-way analysis of variance (ANOVA) and Dunn's post hoc test. Comparisons of categorical variables were performed using Pearson's chi-square, Fisher's exact chi-square, Yates's chi-square, and the Monte Carlo chi-square test.

RESULTS

One hundred twenty-four patients reported DH, showing a prevalence for self-reported DH of 10.2%. Eight hundred forty teeth were diagnosed as having DH, giving a clinical diagnosis rate of DH of 29.4%. Females (76.8%), the 31-40 years age group (26%), housewives (36.8%), and high school education level (38%) had the highest prevalence of DH as demographic properties. A cold stimulus was the most common stimuli trigger for hypersensitivity (97.1%). Occasional pain (55.5%) showed the highest prevalence in terms of frequency of DH. A higher rate of DH was found with the use of medium brushes (47.4%) and brushing twice per day (59.4%) for 1-2 min (56.2%) with the circular method (33.8%) as oral hygiene habits. The buccal surface of the lower right central incisors (5.7%) had the highest prevalence. The most affected teeth by DH were incisors (38.4%). The buccal surfaces (86.3%) of teeth showed a higher high prevalence of DH compared with the lingual surface (52.7%), similar to gingival recession (40.9% vs. 15.7%) and loss of attachment (68.3% vs. 42.6%).

CONCLUSIONS

Clinically diagnosed DH was more common than self-reported DH. Some factors related to patients such as sex (female), the 31-40 years age group, housewives, high school students, using medium brushes, brushing twice per day, and the circular brushing method were more likely to have a risk for DH. Also, buccal surfaces of teeth, gingival recession, and loss of attachment on the buccal surface of teeth should be considered as predisposing factors for DH.

CLINICAL RELEVANCE

To control and prevent DH, clinicians should consider patients' demographics, predisposing factors, and etiologic factors.

Cross-cultural adaptation of the Arabic version of the Dentine Hypersensitivity Experience Questionnaire (DHEQ-15)

OBJECTIVES

Many patients who suffer from Dentine Hypersensitivity (DH) often go undiagnosed because they do not consider DH as serious problem that requires treatment. The use of patient reported outcome measures can help in diagnosis and management of DH problems. The aim of the present study was to adapt cross-culturally the original English version of the Dentine Hypersensitivity Experience Questionnaire (DHEQ-15) for use in Arabic speaking countries.

METHODS

An Arabic version of DHEQ-15 was first developed by forward-backward translation and piloted among a group of dental patients. A cross-sectional study design was then used to test the psychometric properties of the Arabic DHEQ-15 in a wider convenience sample of Libyan dental patients diagnosed with DH. Confirmatory factor analysis was used to test the 3-dimensional distribution of the subscales. The significance level of all statistical tests was set at p≤0.05.

RESULTS

The Arabic DHEQ-15 demonstrated good face and content validity. A total of 462 participants aged on average 39.2 ± 12.9 years took part in the psychometric testing of the Arabic DHEQ-15. The overall Cronbach alpha of the questionnaire was 0.91, and overall Interclass correlation coefficient (ICC) for test-retest repeatability was 0.914. Participants with more severe DH had a significantly higher DHEQ-15 score than those with less severe DH (p<0.001). Those who reported better global rating of their oral health had lower scores on the Arabic DHEQ-15 (p<0.001). Confirmatory factor analysis confirmed 3 subscales of the Arabic DHEQ-15.

CONCLUSIONS

The Arabic DHEQ-15 has been developed and further testing has demonstrated acceptable levels of psychometric properties in an Arabic population. The Arabic DHEQ-15 is a reliable measure of the quality of life impact of DH for use with Arabic speaking populations.

Effect of silver diamine fluoride, potassium nitrate, and glutaraldehyde in reducing the post vital tooth preparation hypersensitivity: A randomized controlled trial

Aim

Hypersensitivity is the most common clinical problem which is encountered by most of dental patients undergoing a vital tooth preparation for a fixed crown prosthesis. The aim of this study is to evaluate the effect of silver diamine fluoride, potassium nitrate, and glutaraldehyde in reducing dentinal hypersensitivity following vital tooth preparation.

Settings and Design

This study is a randomized control trial performed on 119 teeth of 68 patients who are in need of fixed prosthesis treatment.

Materials and Methods

After a thorough clinical examination, patients were allocated into any of the randomly assigned four groups (Control, silver diamine fluoride, potassium nitrate, and glutaraldehyde) and the level of hypersensitivity was measured by blasting air on the surface of tooth at five different intervals (before preparation, after preparation, after application of desensitizers, before cementation and after a follow up period of about 30 days) and is graded using Schiff 's cumulative hypersensitivity index.

Statistical Analysis Used

Kruskal wallis test is used to compare the rate of sensitivity between the 4 groups. Friedman and Wilcoxon test is used to compare the rate of sensitivity at 5 different intervals.

Results

All the desensitizers used in this study reduced the level of hypersensitivity. Among which, silver diamine fluoride was found to be more effective after application, before cementation, and after a follow up period of about 30 days followed by GLUMA and potassium nitrate.

Conclusion

The results of this study suggest that silver diamine fluoride was found to be more effective after application, before cementation of the definitive prosthesis and after a follow up period of 30 days.

A Potassium Based Fluorine Containing Bioactive Glass for Use as a Desensitizing Toothpaste

Potassium releasing bioactive glasses (BAGs) may offer improved relief for dentine hypersensitivity compared to conventional sodium containing BAGs by releasing K⁺ ions for nerve desensitization and occluding dentinal tubules to prevent fluid flow within dentinal tubules. Potassium oxide was substituted for sodium oxide on a molar basis in a fluoride containing BAG used in toothpastes for treating dentine hypersensitivity. The BAG powders were then immersed in an artificial saliva at pH 7 and tris buffer and the pH rise and ion release behavior were characterized by ICP-OES and ISE. The potassium and sodium containing BAGs were characterized by XRD, DSC, FTIR and NMR. Both BAGs presented amorphous diffraction patterns and the glass transition temperature of the potassium glass was higher than that of the sodium glass. The ³¹P MAS-NMR spectra indicated a peak at 2.7 ppm corresponding to apatite and a small peak at −103 ppm indicated crystallization to fluorapatite. Both BAGs dissolved and formed apatite at similar rates, although the dissolution of the potassium glass was slightly slower and it released less fluoride as a result of partial nanocrystallization to fluorapatite upon quenching. The potassium release from the potassium ions could potentially result in nerve deactivation when used in toothpastes.

Long-Term Effectiveness of Treating Dentin Hypersensitivity with Bifluorid 10 and Futurabond U: A Split-Mouth Randomized Double-Blind Clinical Trial

Background: The definition of dental hypersensitivity is “pain derived from exposed dentin in response to chemical, thermal tactile or osmotic stimuli which cannot be explained as arising from any other dental defect or disease”. One of the treatments proposed is tubular occlusion. The aim of this in vivo split-mouth randomized clinical trial was to evaluate the clinical efficacy of a in-office application of a fluoride varnish (Bifluorid 10) and a bonding resin (Futurabond U) in adults with dentin hypersensitivity. Material and methods: A total of 180 teeth were treated with Bifluorid 10 and 160 with Futurabond U. Outcome measurements were taken one or two weeks before treatment, at baseline at the application days, at 1 week and at 1–6 months after first treatment. Results: Both treatments reduced pain intensity. Bifluorid 10 and Futurabond U have similar efficacy in reducing SCHIFF-measured pain reduction, while Bifluorid 10 is significantly more efficient for VAS-measured pain reduction, mainly due to long-term pain reduction. Patient age has a significant negative influence on pain reduction, while the influence of patient gender and BEWE of the tooth is insignificant. Conclusions: Bifluorid 10 and Futurabond U are effective in the treatment of dental hypersensitivity. The RCT was registered at the US National Institutes of Health (ClinicalTrials.gov) #NCT04813848.

Comparative Study of Technologies for Tubule Occlusion and Treatment of Dentin Hypersensitivity

This study aimed to evaluate the occluding/remineralization performance and resistance to acid attacks of the mineralization layer formed by a tooth-desensitizing gel containing amorphous calcium magnesium phosphate (ACMP) particles and compare it to six other desensitizing products available on the market. Similar comprehensive studies are few and there is especially a lack of studies that are up to date. A dentin-disc model was used for in vitro evaluation of the desensitizing toothpastes/gels. Application of the products was performed twice daily for seven days. One set of specimens were evaluated using scanning electron microscopy (SEM) directly after the final treatment and another set was evaluated after an acid challenge, exposing specimens to 2 wt% citric acid. The ACMP desensitizing gel was the only product resulting in complete occlusion by the formation of mineralized material on the dentin surface and inside the tubules. Particle deposition was dominant after treatment with the other desensitizing products, with little or no mineralization, resulting in partial occlusion only. Sensodyne Repair & Protect and Oral-B Pro-Expert showed the highest resistance toward acid attacks. Material inside the tubules remained relatively unaffected by acid attacks in all specimens. The results in this study indicated a great variability among the occluding agents in terms of occlusion and acid resistance of the mineralization layer. The high degree of occlusion and intra-tubular mineralization that could mitigate the effect of acid solubilization indicate that the ACMP desensitizing gel may be a superior option for the treatment of dentin hypersensitivity.

Comparing the Effectiveness of Different Dentinal Desensitizing Agents: In Vitro Study

Objectives

To evaluate the in vitro effectiveness of desensitizing agents in reducing dentine permeability.

Methods

The efficacy of desensitizing agents in reducing dentine permeability by occluding dentine tubules was evaluated using a fluid filtration device that conducts at 100 cmH₂O (1.4 psi) pressure, and SEM/EDX analyses were evaluated and compared. Forty-two dentine discs (n = 42) of 1 ± 0.2 mm width were obtained from caries-free permanent human molars. Thirty dentine discs (n = 30) were randomly divided into 3 groups (n = 10): Group 1: 2.7% wt. monopotassium-monohydrogen oxalate (Mp-Mh oxalate), Group 2: RMGI XT VAR, and Group 3: LIQ SiO₂. Dentine permeability was measured following treatment application after 10 minutes, storage in artificial saliva after 10 minutes and 7 days, and citric acid challenge for 3 minutes. Data were analysed with a repeated measures ANOVA test. Dentine discs (n = 12) were used for SEM/EDX analyses to acquire data on morphological changes on dentine surface and its mineral content after different stages of treatment.

Results

Desensitizing agents' application on the demineralized dentine discs exhibited significant reduction of permeability compared to its maximum acid permeability values. Mp-Mh oxalate showed a significant reduction in dentine permeability (p < 0.05) when compared to RMGI XT VAR and LIQ SiO₂. On SEM/EDX analysis, all the agents formed mineral precipitates that occluded the dentine tubules.

Conclusions

2.7% wt. monopotassium-monohydrogen oxalate was significantly effective in reducing dentine permeability compared to RMGI XT VAR and LIQ SiO₂.

Prevalence of sensitive teeth and associated factors: a multicentre, cross-sectional questionnaire survey in France

BACKGROUND

As far as we know, little data, whether obtained from self-administered questionnaires or upon dental clinical examination, has been published on the prevalence of sensitive teeth (ST) in the French adult population. The objectives of the present work were to estimate ST prevalence and characteristics in the general population of France and to explore the associated factors.

METHOD

A multicentre cross-sectional study was conducted between November 2011 and March 2013 in six French cities. Adult passers-by in public places were invited to answer an electronic questionnaire on a tablet computer. Only people who declared having at least one natural tooth were included in the study. A logistic regression model was used for the multivariate analysis.

RESULTS

The prevalence of ST during the previous 12 months reported by the sample of 2413 participants was 42.2% [95% CI: 40.2-44.1%]. The final logistic regression model showed significant statistical associations between ST and female gender, use of tobacco, consumption of soft drinks, limited access to oral care and poor oral hygiene habits (p < 0.05).

CONCLUSIONS

This study provides prevalence data on ST in a general population in France, which seems to remain high despite the existence of many therapies. It should alert professionals to a clinical manifestation that is becoming increasingly prevalent and that they will have to take into consideration to help reduce the discomfort arising from it.

Pathogenesis, diagnosis and management of dentin hypersensitivity: an evidence-based overview for dental practitioners

Though dentin hypersensitivity (DHS) is one of the most common complaints from patients in dental clinics, there are no universally accepted guidelines for differential diagnosis as well as selection of reliable treatment modalities for this condition. The neurosensory mechanisms underlying DHS remain unclear, but fluid movements within exposed dentinal tubules, i.e., the hydrodynamic theory, has been a widely accepted explanation for DHS pain. As several dental conditions have symptoms that mimic DHS at different stages of their progression, diagnosis and treatment of DHS are often confusing, especially for inexperienced dental practitioners. In this paper we provide an up-to-date review on risk factors that play a role in the development and chronicity of DHS and summarize the current principles and strategies for differential diagnosis and management of DHS in dental practices. We will outline the etiology, predisposing factors and the underlying putative mechanisms of DHS, and provide principles and indications for its diagnosis and management. Though desensitization remains to be the first choice for DHS for many dental practitioners and most of desensitizing agents reduce the symptoms of DHS by occluding patent dentinal tubules, the long-term outcome of such treatment is uncertain. With improved understanding of the underlying nociceptive mechanisms of DHS, it is expected that promising novel therapies will emerge and provide more effective relief for patients with DHS.

TRPM8 Mediates Hyperosmotic Stimuli-Induced Nociception in Dental Afferents

Hyperosmolar sweet foods onto exposed tooth dentin evoke sudden and intense dental pain, called dentin hypersensitivity. However, it remains unclear how hyperosmolar stimuli excite dental primary afferent (DPA) neurons and thereby lead to dentin hypersensitivity. This study elucidated whether TRPM8, which is well known as a cold temperature- or menthol-activated receptor, additionally mediates nociception in response to hyperosmolar stimuli in adult mouse DPA neurons, which are identified by a fluorescent retrograde tracer: DiI. Single-cell reverse transcription polymerase chain reaction revealed that TRPM8 was expressed in subsets of DPA neurons and that TRPM8 was highly colocalized with TRPV1 and Piezo2. Immunohistochemical analysis also confirmed TRPM8 expression in DPA neurons. By using Fura-2-based calcium imaging, application of hyperosmolar sucrose solutions elicited calcium transients in subsets of the trigeminal ganglion neurons, which was significantly abolished by a selective TRPM8 antagonist: N-(3-Aminopropyl)-2-[(3-methylphenyl)methoxy]-N-(2-thienylmethyl)benzamide (AMTB) hydrochloride. When we further examined changes of c-fos expression (a neuronal activation marker) in the spinal trigeminal nucleus after hyperosmolar stimulation onto exposed tooth dentin, c-fos mRNA and protein expression were increased and were also significantly reduced by AMTB, especially in the spinal trigeminal interpolaris-caudalis transition zone (Vi/Vc). Taken together, our results provide strong evidence that TRPM8 expressed in DPA neurons might mediate dental pain as a hyperosmosensor in adult mice.

Dentine hypersensitivity and associated factors: a Nigerian cross-sectional study

Introduction

Prevalence of dentine hypersensitivity (DH) may be on the increase as a result of changing lifestyles. This study aimed to assess the prevalence of DH and relative importance of associated factors in 18-35 year old Nigerians and compare to findings from a similar European study.

Methods

Following ethical approval, 1349 subjects from the six geopolitical zones in Nigeria participated in this cross sectional study. DH was clinically evaluated by cold air tooth stimulation, patient pain rating (yes/no) and investigator rated pain using the Schiff ordinal scale (0-3). Erosive tooth wear using the BEWE index was assessed. A questionnaire regarding the nature of the DH, erosive dietary intakes, tooth brushing habits and other factors was completed by patients. Bivariate analysis was conducted.

Results

32.8% of patients reported pain on tooth stimulation and 32.9% scored ≥1 on Schiff scale for at least one tooth. Questionnaire reported sensitivity was 41.2%. There were statistically significant associations between Schiff score and clinically elicited DH (p < 0.001); and BEWE erosive tooth wear score and clinically elicited DH (p < 0.001). There were significant associations between DH and some oral hygiene practices such as brushing frequency, brush movement and brushing after breakfast. Fresh fruit and fruit/vegetable juice intake also showed significant association.

Conclusion

The most important risk factors of DH for this population in Nigeria appear to be the frequency and characteristics of tooth brushing. This should be considered in its prevention and management.

Ion Channels Involved in Tooth Pain

The tooth has an unusual sensory system that converts external stimuli predominantly into pain, yet its sensory afferents in teeth demonstrate cytochemical properties of non-nociceptive neurons. This review summarizes the recent knowledge underlying this paradoxical nociception, with a focus on the ion channels involved in tooth pain. The expression of temperature-sensitive ion channels has been extensively investigated because thermal stimulation often evokes tooth pain. However, temperature-sensitive ion channels cannot explain the sudden intense tooth pain evoked by innocuous temperatures or light air puffs, leading to the hydrodynamic theory emphasizing the microfluidic movement within the dentinal tubules for detection by mechanosensitive ion channels. Several mechanosensitive ion channels expressed in dental sensory systems have been suggested as key players in the hydrodynamic theory, and TRPM7, which is abundant in the odontoblasts, and recently discovered PIEZO receptors are promising candidates. Several ligand-gated ion channels and voltage-gated ion channels expressed in dental primary afferent neurons have been discussed in relation to their potential contribution to tooth pain. In addition, in recent years, there has been growing interest in the potential sensory role of odontoblasts; thus, the expression of ion channels in odontoblasts and their potential relation to tooth pain is also reviewed.

Prevalence of self-reported versus diagnosed dentinal hypersensitivity: a cross-sectional study and ROC curve analysis

OBJECTIVE

This study aimed to identify and compare the self-reported and diagnosed prevalence of dentinal hypersensitivity (DH) in an University population; and to verify accuracy, sensitivity and specificity of DH stimuli tests.

MATERIAL AND METHODS

Three hundred and eighty patients (67.2% women and 32.8% men) were assessed by questionnaire, clinical exam, tactile and cold water tests. The intensity of DH was assessed using a visual analogue scale, and a calibrated examiner measured the scores using a caliper. The ICC for intra-examiner was 0.990. Scores above 5 mm were considered sensitive teeth. The association between variables was assessed by Chi-square test. ROC curve analysis determined accuracy, sensitivity and specificity of the tests (p < .05).

RESULTS

The mean age of participants was 24.08 years. 158 (41.7%) volunteers self-reported the presence of DH, while, 88.7% of the participants were clinically diagnosed (p = .023). In total, 8958 teeth were evaluated, of those 3367 (37.6%) were diagnosed sensitive. The most prevalent teeth with DH were incisors and premolars. The accuracy of the tests with cold water and tactile were 99%. The sensitivity and specificity for cold water and tactile tests were 99.9%, 99.7%, 99.1% and 87.6%, respectively.

CONCLUSION

The self-reported prevalence of DH was significantly lower than that clinically diagnosed. The cold test proved to be a highly accurate stimulus for the diagnosis of DH.

The effects of different desensitizer agents on shear bond strength of orthodontic brackets after home bleaching: an in vitro study

Purpose

The aim of this study was to test the null hypothesis that no difference exists between shear bond strength values of control and bleaching plus desensitizer applied groups.

Materials and methods

A hundred freshly extracted human premolar teeth were randomly divided into five groups. Group I served as the control group with no bleaching application, while only bleaching was achieved in Group II. Desensitizer containing potassium nitrate-fluoride and casein phosphopeptide amorphous calcium phosphate were applied in Groups III and IV, after bleaching respectively. A bleaching agent containing amorphous calcium phosphate was used in Group V. Shear bond strength tests were carried out using a universal testing machine (Instron Corp., Norwood, MA, USA). Remnant adhesive on the teeth and brackets was examined to score the adhesive remnant index. Kruskal-Wallis and Chi-Square tests were used for statistical analysis of the data.

Results

Statistically significant differences were found among the groups for shear bond strength values (p<.001). The shear bond strength of Group III (8.0±2.2 MPa) was significantly lower than the other groups (p<.05). The highest shear bond strength values were found for Group I (13.6±3.7 MPa) and Group IV (12.8±4.0 MPa). No statistically significant difference was observed between Group II (10.0±2.7 MPa) and Group V (10.8±2.9 MPa). The differences between adhesive remnant index scores of the groups were not statistically significant.

Conclusion

Casein phosphopeptide amorphous calcium phosphate gel application showed a similar shear bond strength value to the control group, while shear bond strength values decreased after using other desensitizers.

The Role of Transient Receptor Potential (TRP) Channels in the Transduction of Dental Pain

Dental pain is a common health problem that negatively impacts the activities of daily living. Dentine hypersensitivity and pulpitis-associated pain are among the most common types of dental pain. Patients with these conditions feel pain upon exposure of the affected tooth to various external stimuli. However, the molecular mechanisms underlying dental pain, especially the transduction of external stimuli to electrical signals in the nerve, remain unclear. Numerous ion channels and receptors localized in the dental primary afferent neurons (DPAs) and odontoblasts have been implicated in the transduction of dental pain, and functional expression of various polymodal transient receptor potential (TRP) channels has been detected in DPAs and odontoblasts. External stimuli-induced dentinal tubular fluid movement can activate TRP channels on DPAs and odontoblasts. The odontoblasts can in turn activate the DPAs by paracrine signaling through ATP and glutamate release. In pulpitis, inflammatory mediators may sensitize the DPAs. They could also induce post-translational modifications of TRP channels, increase trafficking of these channels to nerve terminals, and increase the sensitivity of these channels to stimuli. Additionally, in caries-induced pulpitis, bacterial products can directly activate TRP channels on DPAs. In this review, we provide an overview of the TRP channels expressed in the various tooth structures, and we discuss their involvement in the development of dental pain.

Multifaceted assessment of dentine hypersensitivity, evaluation of demographic prevalence along with associated factors: A cross-sectional study

Background:

Dentine hypersensitivity (DH) is a relatively common problem which may affect the adult population. The etiology remains multi-factorial with interactions between stimulus and pre-disposing factors causing its aggravation.

Aim:

To study the prevalence of DH and associated factors and also to find the association between various factors and DH.

Materials and Methods:

A cross-sectional study was carried out and a total of 5091 patients, both male and females, were evaluated through questionnaire. Out of the total only 1400 patients were included in the study and were further evaluated clinically. A complete demographic data was obtained and the DH was confirmed by the use of air -water jet of the dental chair and scratching the suspected tooth with a dental probe. The pain response of the subject was recorded using the visual analog scale (VAS) and verbal rating scale (VRS). The data obtained was statistically evaluated and Chi-square test was applied for comparison of different demographic factors with DH.

Results:

The overall prevalence of DH was 27.4%. Various demographic factors were found to affect DH such as age, gender, education, and diet. The most common stimulus was found to be cold (21.4%) and common predisposing factor was gingival recession and attrition (28.6%). Clinical examination yielded a statistically significant association between VAS and VRS scores for DH and demographic factors.

Conclusion:

The prevalence of DH in present study was 27.4% which is attributed to gingival recession as predisposing factor and cold stimuli as the precipitating factor.

TRPM8 and TRPA1 do not contribute to dental pulp sensitivity to cold

Sensory neurons innervating the dental pulp have unique morphological and functional characteristics compared to neurons innervating other tissues. Stimulation of dental pulp afferents whatever the modality or intensity of the stimulus, even light mechanical stimulation that would not activate nociceptors in other tissues, produces an intense pain. These specific sensory characteristics could involve receptors of the Transient Receptor Potential channels (TRP) family. In this study, we compared the expression of the cold sensitive receptors TRPM8 and TRPA1 in trigeminal ganglion neurons innervating the dental pulp, the skin of the cheek or the buccal mucosa and we evaluated the involvement of these receptors in dental pulp sensitivity to cold. We showed a similar expression of TRPM8, TRPA1 and CGRP in sensory neurons innervating the dental pulp, the skin or the mucosa. Moreover, we demonstrated that noxious cold stimulation of the tooth induced an overexpression of cFos in the trigeminal nucleus that was not prevented by the genetic deletion of TRPM8 or the administration of the TRPA1 antagonist HC030031. These data suggest that the unique sensory characteristics of the dental pulp are independent to TRPM8 and TRPA1 receptors expression and functionality.

The effect of oxalate-based desensitizers on the microleakage and shear bond strength of resin modified glass ionomer

Background

The first line of intervention to alleviate tooth sensitivity is to use dentin desensitizers such as oxalate-based desensitizers. When the dentin sensitivity continues even after application of desensitizers the next intervention would be restoration of the lesion. The aim of this in vitro study was to investigate the effect of prior application of oxalate-based desensitizer on the marginal microleakage and shear bond strength of resin modified glass ionomer (RMGI) restorations.

Material and Methods

In order to prepare the specimens for microleakage test standard class v cavities were prepared on buccal surfaces of 45 teeth. The specimens were randomly divided into three equal groups. In control group, the cavities were restored with RMGI. In group 2, oxalate-based desensitizer was applied and the specimens were kept in distilled water for 14 days before restoration. In group 3 the specimens were prepared similar to group 2 and the surface of the cavities were slightly cut with bur before restoration. Methyleneblue penetration was evaluated using stereomicroscope. The data were analyzed using non-parametric tests. For shear bond strength test cervical dentin specimens were prepared and were divided into 3 groups. Surface treatments were similar to microleakage test. RMGI was packed into cylindrical plastic molds which were placed on the cut surface of the tooth and light cured. The data were analyzed by one-way ANOVA.

Results

There was not any significant difference in dye penetration in dentin margins among the groups, but microleakage in enamel margins of group 2 and 3 was higher than group 1. There was no significant difference in shear bond strength among the groups (p =0.285).

Conclusions

Non carious cervical lesions which were treated for hypersensitivity with oxalate-based desensitizers could be restored with resin modified glass ionomer if the hypersensitivity persists.

Key words:Dentin hypersensitivity, oxalate-based desensitizers, microleakage, shear bond strength.

Patient-Centered Dentinal Hypersensitivity Treatment Outcomes: Results from the National Dental PBRN

Dentinal hypersensitivity (DH) can have a significant impact on oral health and functioning, and it is a clinical symptom commonly managed by dentists during routine clinical practice. DH symptoms are typically elicited by otherwise innocuous, nonpainful stimuli applied to exposed dentin (e.g., tactile stimuli, warming or cooling temperatures or air puffs). Treatment approaches have sought to directly target the dentinal pulp tissues or close dentinal tubules via dental office care and treatment services (fluoride varnishes, glutaraldehydes, bonding agents, sealants, oxalates, or lasers) or home care services (toothpastes or dentifrices containing fluoride or potassium nitrate compounds). The purpose of this prospective multicenter cohort study was to assess how community-based dentists from the National Dental Practice-Based Research Network (National Dental PBRN) manage DH and whether the effectiveness of DH treatments can be assessed in those settings. A total of 171 dentists recruited 1862 subjects with DH from their existing patients. Dentists then recommended and provided DH treatment as appropriate. Treatment choice was at the discretion of the dentists. Patients rated their DH pain at baseline and 1, 4, and 8 wk during the course of their treatments. They used pain intensity and unpleasantness visual analog scales and 4 labeled magnitude scales and rated their satisfaction with treatment after 8 wk. Patients were provided reminders postbaseline via email, texting, or voice mail. These patient-centered outcomes served as the principal measures for the assessment of treatment because treatments sought to alleviate DH symptoms. The patients with DH who reported pain reduction from dentist-provided treatments (glutaraldehyde/HEMA [hydroxyethyl methacrylate] compounds, oxalates, and bonding agents), dentists' advice and counseling regarding oral habits and diet, and patient-applied fluoride toothpaste reported a concomitant positive rating of satisfaction with DH treatments. The results from this study support the feasibility of engaging network practices to assess the effectiveness of clinical DH treatments. Knowledge Transfer Statement: National Dental PBRN dentists provide a range of procedures to treat dentinal hypersensitivity. In this large nonrandomized study designed to assess clinical care and to capture patient-reported outcomes, about 60% of patients reported improvement in pain. This study demonstrated the feasibility of engaging network dentists and their patients to assess treatment effectiveness. Future studies will explore the feasibility of imposing randomization and measuring patient compliance with treatment in the manner that this treatment is provided.

Using classification and regression tree modelling to investigate response shift patterns in dentine hypersensitivity

Background

Dentine hypersensitivity (DH) affects people’s quality of life (QoL). However changes in the internal meaning of QoL, known as Response shift (RS) may undermine longitudinal assessment of QoL. This study aimed to describe patterns of RS in people with DH using Classification and Regression Trees (CRT) and to explore the convergent validity of CRT with the then-test and ideals approaches.

Methods

Data from an 8-week clinical trial of mouthwashes for dentine hypersensitivity (n = 75) using the Dentine Hypersensitivity Experience Questionnaire (DHEQ) as the outcome measure, were analysed. CRT was used to examine 8-week changes in DHEQ total score as a dependent variable with clinical status for DH and each DHEQ subscale score (restrictions, coping, social, emotional and identity) as independent variables. Recalibration was inferred when the clinical change was not consistent with the DHEQ change score using a minimally important difference for DHEQ of 22 points. Reprioritization was inferred by changes in the relative importance of each subscale to the model over time.

Results

Overall, 50.7% of participants experienced a clinical improvement in their DH after treatment and 22.7% experienced an important improvement in their quality of life. Thirty-six per cent shifted their internal standards downward and 14.7% upwards, suggesting recalibration. Reprioritization occurred over time among the social and emotional impacts of DH.

Conclusions

CRT was a useful method to reveal both, the types and nature of RS in people with a mild health condition and demonstrated convergent validity with design based approaches to detect RS.

Management of dentin hypersensitivity by practitioners in The National Dental Practice-Based Research Network

BACKGROUND

Dentin hypersensitivity (DH) is a condition commonly encountered in clinical dental practice. The authors conduct a study to identify the treatments recommended to manage DH among dentists in the United States.

METHODS

The authors conducted a multicenter study of 1,862 patients with DH who received a diagnosis and were treated by 171 dentists with The National Dental Practice-Based Research Network.

RESULTS

The most common treatment recommended was desensitizing over-the-counter (OTC) potassium nitrate toothpaste (alone or in combination with other treatments) for 924 of 1,862 patients (50%). This was followed by an application of fluoride varnish (FV) for 516 patients (28%) and a prescription for fluoride toothpaste for 314 patients (17%). Restorative treatments were recommended to 151 patients (8%). The most common single treatment recommendation was desensitizing OTC potassium nitrate toothpaste, recommended to 335 patients (18%). The most frequent combination of 2 treatment modalities was FV and desensitizing OTC potassium nitrate toothpaste, recommended to 100 patients (5%). A total of 890 of 1,862 patients (48%) with DH received a recommendation for 1 treatment modality, and 644 of 1,862 patients (35%) received a recommendation for a combination of 2 treatment modalities, most frequently an application of FV along with desensitizing OTC potassium nitrate toothpaste (100/1,862; 5%).

CONCLUSIONS

Desensitizing OTC potassium nitrate toothpaste and fluoride products were the most widely recommended products to manage DH in the practice setting.

PRACTICAL IMPLICATIONS

Our results suggest that most network clinicians preferred noninvasive treatment modalities when treating DH.

Knowledge, diagnosis and management of dentine hypersensitivity: a national survey of dentists in Nigeria

AIM

To assess the knowledge of Nigerian dentists regarding dentine hypersensitivity (DH) and their methods of diagnosis and management.

METHODS

A cross-sectional questionnaire-based study of dentists practicing in all six geopolitical zones of Nigeria was conducted. The questionnaire focussed on participant's demography, exposure to patients with DH, knowledge-based questions, diagnosis and management of DH. Data analysis using EPI Info statistical software determined frequencies and proportions. Associations between discrete variables were assessed using the chi-square test (P ≤ 0.05).

RESULTS

A total of 1,057 dentists responded; the majority (83.8%) had practiced for up to 15 years, and 92.0% reported that, on average, between one and 10 of their patients each week complained of DH. The majority (92.8%) of dentists described DH as stimulated brief pain from the tooth; 24.2% expressed that DH can be treated by altering the number of dentinal tubules. A diagnosis of DH is made by tapping (20.6%) or scratching (73.4%) the tooth. Although radical treatments, such as extraction (24.7%) and root canal therapy (34.5%), were mentioned by some, the majority identified aetiological and predisposing factors (98.8%) and provided diet (95.1%) and oral hygiene (95%) counselling as part of the management of DH. Evaluation of 36 knowledge-based questions revealed that only 1.8% of the respondents provided at least 25 correct answers. Knowledge was significantly associated with respondent age and number of years in practice (P ≤ 0.05) but was not associated with the number of patients with DH seen per week (P = 0.46).

CONCLUSION

Dentists practicing in Nigeria exhibited knowledge gaps concerning DH and its diagnosis and management.

Dentinal tubules occluded by bioactive glass-containing toothpaste exhibit high resistance toward acidic soft drink challenge

BACKGROUND

Dentine hypersensitivity is a common problem attributed by patent dentinal tubules. Ingredients incorporated in toothpastes aim to occlude patent dentinal tubules to minimize the dentine hypersensitivity. However, frequent consumption of acidic soft drinks may reverse the dentinal tubules' occlusion. In this in vitro study, the efficacy of dentinal tubules occluded by commercially available toothpastes to withstand different durations of an acidic soft drink challenge was investigated.

METHODS

One hundred and twenty dentine discs were divided into three groups. The discs from each group were brushed with toothpaste containing bioactive glass, arginine and control toothpaste. Each group was then divided into four subgroups and exposed to acidic soft drink over four different time durations.

RESULTS

The scoring and the percentage of occluded dentinal tubules by Novamin-containing toothpaste was significantly better compared with arginine or the control toothpaste. Acidic soft drink challenge reduced the extent of dentinal tubules occlusion along with time. Dentinal tubules occluded by Novamin-containing toothpaste withstand the acidic challenge comparatively for a longer period.

CONCLUSIONS

The findings demonstrated that occlusion of dentinal tubules is more efficient by the bioactive glass-containing toothpaste and thus may contribute to its better resistance to acidic soft drink challenge.

Effect and Stability of Poly(Amido Amine)-Induced Biomineralization on Dentinal Tubule Occlusion

In recent years, scientists have developed various biomaterials to remineralize human teeth to treat dentine hypersensitivity. Poly(amido amine) (PAMAM) dendrimers have become a research focus in this field. It has been demonstrated that PAMAM is able to create precipitates both on the surface of and within the dentinal tubules, however, there is little information about its effect on reducing dentine permeability in vitro. This study aimed to evaluate the in vitro effectiveness and stability of the fourth generation amine-terminated PAMAM on dentinal tubule occlusion, especially on dentine permeability. Sodium fluoride (NaF), which has been widely used as a desensitizing agent, is regarded as positive control. Demineralized sensitive dentine samples were coated with PAMAM or sodium fluoride solutions and soaked in artificial saliva (AS) at 37 °C for different periods. Four weeks later, samples in each group were then equally split into two subgroups for testing using a brushing challenge and an acid challenge. Dentine permeability of each specimen was measured before and after each challenge using a fluid filtration system. Dentine morphology and surface deposits were characterized by scanning electron microscope (SEM) and analyzed with Image-Pro Plus software. Data were evaluated through multifactorial ANOVA with repeated measures and pair-wise comparisons at a level of 5%. The results showed that PAMAM and NaF significantly reduced dentine permeability to 25.1% and 20.7%. Both of them created precipitates on dentine surfaces after AS immersion for 28 days. PAMAM-induced biomineralization not only on dentine surfaces, but also deeper in dentinal tubules, significantly reduced dentine permeability. Moreover, PAMAM-induced biomineralization elicited excellent stable occlusion effects after acid challenge. In conclusion, PAMAM demonstrated a strong ability to resist acid and showed great potential to be used in the treatment of dentine hypersensitivity in future.

Evaluation of Five Different Desensitizers: A Comparative Dentin Permeability and SEM Investigation In Vitro

BACKGROUND/OBJECTIVE

The purpose of this study was to evaluate the efficacy and durability of five different dentin desensitizers (Gluma Desensitizer Powergel, Bifluorid 12, Gluma Self Etch Bond, D/Sense Crystal, Nupro Sensodyne Prophylaxis Paste with Novamin) on tubule occlusion and dentin permeability reduction in vitro.

METHOD

The quantitative changes in permeability of 100 dentin discs were measured after desensitizer treatments and following post-treatments of 6% citric acid challenge for 1 min or immersion in artificial saliva for 24 hours under hydrostatic pressure generated by a computerised fluid filtration meter. Qualitative SEM analyses were also carried out.

RESULTS

Dentin permeability decreased after desensitizer application in all groups. Nevertheless, only the difference between 'Gluma Self Etch Bond' and 'Nupro Sensodyne Prophylaxis Paste with Novamin' groups was significantly different (p<0.05). Dentin permeability increased significantly after post-treatments (p<0.05). There was no statistically difference among the citric acid-subgroups (p>0.05). Of all the artificial saliva-subgroups, only the difference between 'D/Sense Crystal' and 'Bifluorid 12' was significantly different (p<0.05). In SEM analysis, morphological changes were detected on the dentin surface and within the tubules following desensitizer treatments and post-treatments.

CONCLUSION

All the desensitizers significantly reduced dentin permeability by changing the morphology of the dentin surface and/or dentinal tubules. Following post-treatments, there was some reduction in the efficacy of the desensitizers which was represented by the reduction in permeability values. SEM analysis revealed some physical changes in the dentin structure which can partly give an explanation to the reduced efficacy of tested desensitizers.

Management of Dentin Hypersensitivity by National Dental Practice-Based Research Network practitioners: results from a questionnaire administered prior to initiation of a clinical study on this topic

Background

Dentin hypersensitivity (DH) is a common problem encountered in clinical practice. The purpose of this study was to identify the management approaches for DH among United States dentists.

Methods

One hundred eighty five National Dental Practice-Based Research Network clinicians completed a questionnaire regarding their preferred methods to diagnose and manage DH in the practice setting, and their beliefs about DH predisposing factors.

Results

Almost all dentists (99%) reported using more than one method to diagnose DH. Most frequently, they reported using spontaneous patient reports coupled with excluding other causes of oral pain by direct clinical examination (48%); followed by applying an air blast (26%), applying cold water (12%), and obtaining patient reports after dentist’s query (6%). In managing DH, the most frequent first choice was desensitizing, over-the-counter (OTC), potassium nitrate toothpaste (48%), followed by fluorides (38%), and glutaraldehyde/HEMA (3%). A total of 86% of respondents reported using a combination of products when treating DH, most frequently using fluoride varnish and desensitizing OTC potassium nitrate toothpaste (70%). The most frequent predisposing factor leading to DH, as reported by the practitioners, was recessed gingiva (66%), followed by abrasion, erosion, abfraction/attrition lesions (59%) and bruxism (32%).

Conclusions

The majority of network practitioners use multiple methods to diagnose and manage DH. Desensitizing OTC potassium nitrate toothpaste and fluoride formulations are the most widely used products to manage DH in dental practice setting.

Penetration of sub-micron particles into dentinal tubules using ultrasonic cavitation

OBJECTIVES

Functionalised silica sub-micron particles are being investigated as a method of delivering antimicrobials and remineralisation agents into dentinal tubules. However, their methods of application are not optimised, resulting in shallow penetration and aggregation. The aim of this study is to investigate the impact of cavitation occurring around ultrasonic scalers for enhancing particle penetration into dentinal tubules.

METHODS

Dentine slices were prepared from premolar teeth. Silica sub-micron particles were prepared in water or acetone. Cavitation from an ultrasonic scaler (Satelec P5 Newtron, Acteon, France) was applied to dentine slices immersed inside the sub-micron particle solutions. Samples were imaged with scanning electron microscopy (SEM) to assess tubule occlusion and particle penetration.

RESULTS

Qualitative observations of SEM images showed some tubule occlusion. The particles could penetrate inside the tubules up to 60μm when there was no cavitation and up to ∼180μm when there was cavitation.

CONCLUSIONS

The cavitation bubbles produced from an ultrasonic scaler may be used to deliver sub-micron particles into dentine. This method has the potential to deliver such particles deeper into the dentinal tubules.

CLINICAL SIGNIFICANCE

Cavitation from a clinical ultrasonic scaler may enhance penetration of sub-micron particles into dentinal tubules. This can aid in the development of novel methods for delivering therapeutic clinical materials for hypersensitivity relief and treatment of dentinal caries.

Effectiveness of two different desensitizing varnishes in reducing tooth sensitivity: a randomized double-blind clinical trial

PURPOSE

The aim of this study is to evaluate and compare the effectiveness of two different desensitizing varnishes.

MATERIALS AND METHODS

Ninety healthy adults suffering from tooth sensitivity were divided into three groups. Two different varnishes were used for the study: Fluor Protector S, containing 7700 ppm fluoride (group I), and Cervitec F, containing 1400 ppm fluoride and 0.3% chlorhexidine (group II). A placebo containing water and ethanol was applied for the third group. Tooth sensitivity was collected according the Schiff' scale at baseline and after 30 and 90 days.

RESULTS

Group I and group II improved with statistically significant results. Group III did not show any improvements.

CONCLUSIONS

Desensitizing varnishes are a valid treatment for tooth hypersensitivity.

Progression of erosive lesions after Nd:YAG laser and fluoride using optical coherence tomography

This study aimed to use optical coherence tomography (OCT) to assess the progression of erosive lesions after irradiation with Nd:YAG laser and application of topical fluoride. One-hundred and twenty dentin samples (4 × 4 × 2 mm) obtained from bovine incisors were used. Samples were protected with acid-resistant nail varnish, with exception of a central circular area 2 mm in diameter. All samples were submitted to erosive cycles with citric acid solution 0.05 M (citric acid monohydrate-C6H8O7·H2O); M = 210.14 g/mol) pH 2.3, at room temperature, for 20 min, 2×/day, throughout 20 days. After 10 days of acid challenges, lesions became visible, and each group received a different treatment (n = 15): control (without treatment), topical application of sodium fluoride 2 % for 4 min; Nd:YAG laser with different irradiation parameters (1, 0.7, and 0.5 W); and the association of fluoride with the laser parameters. OCT readouts were performed on day 01 (before the first acid challenge-OCT1), on day 05 (OCT2), day 10 (OCT3-after treatment), day 15 (OCT4), day 17 (OCT5), and day 20 (OCT6). The OCT images generated made it possible to measure the amount of tooth tissue loss over the 20 days of erosive cycle, before and after treatments, and to monitor early dentin demineralization progression. After statistical analysis, the fluoride group was observed to be the one that showed smaller loss of tissue over time. The OCT technique is promising for diagnosing and monitoring erosive lesion damage; however, further in vitro and in vivo research is needed to improve its use.

Caries-resistant bonding layer in dentin

The present study examined the mechanism for caries resistance and the pulp responses in vital teeth following the use of the augmented-pressure adhesive displacement technique. Dentin adhesives were applied to the surface of sound dentin disks in 4 experimental groups: non-antibacterial adhesive and gentle adhesive displacement (N-G), non-antibacterial adhesive and augmented-pressure adhesive displacement (N-H), antibacterial adhesive and gentle adhesive displacement (A-G), antibacterial adhesive and augmented-pressure adhesive displacement (A-H). The depth of demineralization induced by biological or chemical demineralization models was measured using confocal laser scanning microscopy and analyzed with two-way ANOVA. Pulp responses of vital dog's teeth to the augmented-pressure adhesive displacement technique were evaluated using light microscopy. Depth of demineralization was significantly affected by "adhesive type" and "intensity of adhesive displacement" for biological demineralization. For chemical demineralization, only "intensity of adhesive displacement" showed significant influence on lesion depth. Pulp response of 0.1, 0.2 and 0.3 MPa groups showed only moderate disorganization of the odontoblast layer at 24 hours that completely re-organized after 3 weeks. Augmented-pressure adhesive displacement improves the caries resistance property of bonded dentin and does not cause irreversible pulpal damage to vital teeth when the air pressure employed is equal or smaller than 0.3 MPa.

Tertiary Dentin Formation after Indirect Pulp Capping Using Protein CPNE7

If there is a partial loss of dentin, the exposed dentinal surface should be protected by an indirect pulp capping (IPC) procedure to preserve pulp vitality and prevent symptoms of dentin hypersensitivity. In our previous study, copine7 (CPNE7) induced odontoblast differentiation in vitro and promoted dentin formation in vivo. The aim of this study was to investigate the possibility of IPC therapy using the CPNE7 protein at the exposed dentinal surface and the resulting effects on tertiary dentin formation in a beagle model. CPNE7 promoted mineralization of odontoblasts and had high calcium ion-binding capacity. The in vivo IPC model with canine teeth showed that regeneration of physiologic reactionary dentin with dentinal tubule structures was clearly observed beneath the remaining dentin in the CPNE7 group, whereas irregular features of reparative dentin were generated in the mineral trioxide aggregate (MTA) group. The CPNE7+MTA group also showed typical reactionary dentin without reparative dentin, showing synergistic effects of CPNE7 with MTA. A scanning electron microscopy analysis showed that dentinal tubules beneath the original dentin were occluded by the deposition of peritubular dentin in the CPNE7 and CPNE7+MTA groups, whereas those in the control group were opened. Therefore, CPNE7 may be able to serve as a novel IPC material and improve symptoms of dentin hypersensitivity.

Improved secondary caries resistance via augmented pressure displacement of antibacterial adhesive

The present in vitro study evaluated the secondary caries resistance potential of acid-etched human coronal dentin bonded using augmented pressure adhesive displacement in conjunction with an experimental antibacterial adhesive. One hundred and twenty class I cavities were restored with a commercial non-antibacterial etch-and-rinse adhesive (N) or an experimental antibacterial adhesive (A) which was displaced by gentle air-blow (G) or augmented pressure air-blow (H). After bonding and restoration with resin composite, the resulted 4 groups (N-G, N-H, A-G and A-H) were exposed to Streptococcus mutans biofilm for 4, 8, 15, 20 or 25 days. The development of secondary caries in the bonding interface was then examined by confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM). Data acquired from 15, 20 and 25 days of artificial caries induction were analyzed with three-way ANOVA at α = 0.05. The depth of the artificial carious lesions was significantly affected by “adhesive type” (Single Bond 2 vs experimental antibacterial adhesive p = 0.003), “intensity of adhesive displacement” (gentle vs augmented-pressure adhesive displacement; p < 0.001), as well as “artificial caries induction time” (p < 0.001). The combined use of augmented pressure adhesive displacement and experimental antibacterial adhesive reduces the progression of secondary caries.