Enamel crack association with tooth age and wear severity: An optical coherence tomography study.

PURPOSE: To investigate the association of dental enamel cracks with estimated tooth age and varying tooth wear severities. METHODS: 355 premolars were sorted from a pool of extracted human teeth, based on their estimated age range: 21-40, 41-60 years old, determined by a dental forensic method and on the presence/severity of lesions: none, mild, moderate and severe wear (Basic Erosive Wear Examination Index). The buccal and lingual surfaces of the teeth were inspected for cracks under an optical coherence tomography system. Images were evaluated according to the following scores: 0= no crack; 1= crack beginning and terminating within the enamel, not reaching the outer surface; 2= crack extending from outer enamel surface terminating within the enamel; 3= crack extending from within enamel terminating at or beyond the dentin-enamel junction (DEJ); 4= crack extending from outer enamel surface terminating at or beyond the DEJ. Data were analyzed by Spearman correlations and Mantel-Haenszel chi-square tests. RESULTS: Estimated tooth age and crack score were moderately correlated. Crack scores increased between each range of estimated tooth age (P< 0.050). Occlusal surfaces showing moderate or severe wear had higher buccal crack scores than occlusal surfaces having no wear (P< 0.020) and mild wear (P< 0.001). Buccal surfaces presenting severe wear had higher buccal crack scores than buccal surfaces with no wear, mild or moderate wear (P< 0.001). Premolars having severe wear had significantly higher crack scores than premolars showing no, mild or moderate wear lesions. CLINICAL SIGNIFICANCE: Knowing that older and more severely worn teeth are more prone to enamel cracks allows clinicians to better diagnose, monitor, and prevent further damage to teeth.

Efficacy of stannous, fluoride and their their combination in dentin erosion prevention in vitro.

The aim of this study was to compare the protective effects of solutions containing stannous (Sn), fluoride (F) and their combination in the prevention of dentin erosion. Forty bovine root dentin specimens (4'4'2 mm(3)) were prepared and randomly assigned to 4 groups (n = 10): SnCl2 (800 ppm/6.7 mM Sn), NaF (250 ppm/13 mM F), NaF/SnCl2 (800 ppm/6.7 mM Sn; 250 ppm/13 mM F), and deionized water (DIW) as a negative control. An acquired pellicle was formed on dentin samples by incubation in clarified, pooled, stimulated human saliva for 24 hours. The specimens were subjected to 5 daily cycles, each consisting of 5 of min demineralization (0.3%/15.6 mM citric acid, pH 2.6, 6'/day) and 60 min of re-mineralization in clarified human saliva. Thirty minutes after the 1st, 3rd and 5th demineralization episodes of each day, the specimens were treated with one of the test solutions for 2 min. Surface loss was measured via optical profilometry. Mixed-model ANOVA followed by Tukey's test were used for the statistical analysis. Sn, F, and their combination significantly reduced the dentin surface loss by 23%, 36%, and 60% compared with DIW, respectively. All groups were significantly different (p < 0.05). The combination of Sn and F significantly reduced the amount of dentin surface loss compared with all other groups. The F group also significantly reduced surface loss compared with Sn and DIW, followed by the Sn group, which showed significantly greater protection compared with the DIW control. The daily use of a combined fluoride and stannous solution is promising for preventing dentin erosion.

Efficacy of stannous, fluoride and their their combination in dentin erosion prevention in vitro

The aim of this study was to compare the protective effects of solutions containing stannous (Sn), fluoride (F) and their combination in the prevention of dentin erosion. Forty bovine root dentin specimens (4’4’2 mm3) were prepared and randomly assigned to 4 groups (n = 10): SnCl2(800 ppm/6.7 mM Sn), NaF (250 ppm/13 mM F), NaF/SnCl2 (800 ppm/6.7 mM Sn; 250 ppm/13 mM F), and deionized water (DIW) as a negative control. An acquired pellicle was formed on dentin samples by incubation in clarified, pooled, stimulated human saliva for 24 hours. The specimens were subjected to 5 daily cycles, each consisting of 5 of min demineralization (0.3%/15.6 mM citric acid, pH 2.6, 6’/day) and 60 min of re-mineralization in clarified human saliva. Thirty minutes after the 1st, 3rd and 5th demineralization episodes of each day, the specimens were treated with one of the test solutions for 2 min. Surface loss was measured via optical profilometry. Mixed-model ANOVA followed by Tukey’s test were used for the statistical analysis. Sn, F, and their combination significantly reduced the dentin surface loss by 23%, 36%, and 60% compared with DIW, respectively. All groups were significantly different (p < 0.05). The combination of Sn and F significantly reduced the amount of dentin surface loss compared with all other groups. The F group also significantly reduced surface loss compared with Sn and DIW, followed by the Sn group, which showed significantly greater protection compared with the DIW control. The daily use of a combined fluoride and stannous solution is promising for preventing dentin erosion.