Triple Function of Amelogenin Peptide-Chitosan Hydrogel for Dentin Repair

Biomimetic strategies like peptide-guided collagen mineralization promise to enhance the effectiveness of dentin remineralization. We recently reported that rationally designed amelogenin-derived peptides P26 and P32 promoted apatite nucleation, mineralized collagen, and showed potential in enamel regrowth and dentin remineralization. To facilitate the clinical application of amelogenin-derived peptides and to uncover their effectiveness in repairing dentin, we have now implemented a chitosan (CS) hydrogel for peptide delivery and have investigated the effects of P26-CS and P32-CS hydrogels on dentin remineralization using 2 in situ experimental models that exhibited different levels of demineralization. The efficacy of the peptide-CS hydrogels in dentin repair was evaluated by characterizing the microstructure, mineral density, mineral phase, and nanomechanical properties of the remineralized samples. The new strategy of atomic force microscopy PeakForce quantitative nanomechanical mapping was used for direct visualization and nanomechanical analysis of repaired dentin lesions across the lesion depth. Results from the 2 models indicated the potential triple functions of peptide-CS hydrogels for dentin repair: building a highly organized protective mineralized layer on dentin, occluding dentinal tubules by peptide-guided in situ mineralization, and promoting biomimetic dentinal collagen remineralization. Importantly, peptides released from the CS hydrogel could diffuse into the dentinal matrix and penetrate the dentinal tubules, leading to both surface and subsurface remineralization and tubule occlusion. Given our previous findings on peptide-CS hydrogels' potential for remineralizing enamel, we see further promise for hydrogels to treat tooth defects involving multiple hard tissues, as in the case of noncarious cervical lesions.

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.

In Vitro Evaluation of Dentin Tubule Occlusion for Novel Calcium Lactate Phosphate (CLP) Paste

Introduction: The objective of this in vitro study is to evaluate the effective and long-term occlusion of dentinal tubules using a novel calcium lactate phosphate (CLP) based desensitizing agent. Methods: Dentin disks (n = 9) were pre-etched using 1 M lactic acid for 30 s and individually treated with Colgate^® Pro-Relief™ paste, CLP paste, and double distilled water (ddH₂O) by a rubber-cupped handpiece. Dentin disks were analyzed under optical micrographs for pre-treatment, directly after treatment, and 14 days post-treatment. One-way ANOVA and post-hoc Tukey’s test were used to determine whether there were any statistically significant differences in dentinal tubule diameter. Results: A significant decrease occurred in the mean tubule diameter for dentin disks treated with CLP paste. A decrease was observed from 3.52 ± 0.83 µm to 2.62 ± 0.42 µm right after treatment, further decreasing to 1.71 ± 0.45 µm after immersion in artificial saliva for 14 days (p < 0.05). Conclusions: The results suggest that the CLP based desensitizing paste has remineralization properties and provides instant and lasting effectiveness in dentinal tubule occlusion.

Prevalence of dentinal hypersensitivity and study of associated factors: a cross-sectional study based on the general dental population of Davangere, Karnataka, India

BACKGROUND

Dentin hypersensitivity (DH) is a common clinical finding with a wide variation in prevalence and aetiological factors. The aim of this cross-sectional study was to determine the prevalence and examine some associated aetiological factors of DH in a study of an Indian population residing in and around Davangere district of Karnataka.

MATERIAL AND METHODS

A total of 404 patients (3,859 teeth) were examined for the presence of DH by means of a questionnaire and intraoral tests (air and tactile stimuli). Plaque, gingival recession, abrasion/erosion, labioversion and toothbrushing habits were noted.

RESULTS

A total of 795 teeth, in 404 patients, were diagnosed as having DH, giving an overall prevalence figure for DH of 20.6%. The chi-square test and the Z-test values for proportions were used to evaluate statistical correlations. The 36-45 years' age group was the cohort with the highest number of subjects with DH, and female subjects had greater predilection for DH compared with male subjects. Incisors were the tooth type most affected. DH was significantly correlated with gingival recession, labioversion and abrasion/erosion (P<0.05). Both gingival recession and abrasion/erosion were significantly correlated with brushing once daily in a horizontal direction and use of a toothbrush with medium-hardness bristles (P<0.05).

CONCLUSION

The prevalence of DH in the Indian population is 20.6%, with a higher predilection for DH in the age cohort 36-45 years and in female subjects. DH is a multifactorial entity with several aetiological factors, making its diagnosis and treatment a challenge for the clinician.

Exploring some aspects associated with dentine hypersensitivity in children

BACKGROUND

The etiology of dentine hypersensitivity (DH) is still inconclusive and there are few studies concerning it in children.

AIM

To evaluate clinical, dietary, and salivary variables in children with DH complaints.

DESIGN

Forty-eight children were asked about DH. Data regarding dietary habits were collected from the children's parents and an examination was performed to determine dental erosion. Dental biofilm was estimated by oral hygiene status, according to Greene and Vermillion's Simplified Oral Hygiene Index (OHI-S). Whole saliva was collected under mechanical stimulation and evaluated salivary flow rate, initial pH, buffer capacity, and calcium and phosphate concentrations. The temperature of soft drinks, drinking method, sense of bitter taste, and other variables were also determined. Possible factors associated with DH were analyzed by univariate and multiple Poisson regression analyses. The prevalence ratio (PR) values and 95% confidence intervals (95% CI) were calculated.

RESULTS

DH was associated with the presence of dental erosion (PR; 95% CI = 2.23; 1.05 to 4.71) and salivary flow rate (2.49; 1.05 to 5.91). When the presence of erosion was not included, other variables were retained as follows: bitter taste (2.36; 1.38 to 4.03), OHI-S (0.47; 0.23 to 0.97).

CONCLUSION

DH in children is associated with factors related to dental erosion.

Efficacy of desensitizing dentifrices to occlude dentinal tubules

Dentine hypersensitivity occurs when patent dentinal tubules are subjected to external stimuli, with pain being reduced by products that occlude tubules. This study compared the efficacy of a recently developed arginine-containing dentifrice, two established strontium-based products, and a fluoride control to occlude tubules when subjected to acid challenge. Dentine specimens with patent tubules were divided into four groups that were treated with a slurry consisting of one of the pastes mixed with stimulated human saliva. Treated specimens were further subdivided and soaked in 0.3% citric acid for 10 s, 30 s, 2 min, 5 min or 10 min. Tubule occlusion on representative scanning electron microscopy images was scored by blind review. All three desensitizing pastes offered good tubule occlusion, which was maintained to varying degrees following acidic challenge. After immersion in acid for 10 and 30 s, the strontium acetate- and arginine-containing pastes almost fully occluded tubules, but only the strontium acetate paste retained this level of occlusion after immersion in acid for 2 min, with strong statistical evidence that this paste occluded more tubules than the other pastes after immersion in acid for 2 or 5 min. This suggests that strontium acetate pastes may be the most effective at reducing dentine hypersensitivity.