The Effect of Three Desensitizing Toothpastes on Dentinal Tubules Occlusion and on Dentin Hardness.

There are two main methods used for dentin hypersensitivity (DH) treatment: dentinal tubule occlusion and blockage of nerve activity. Dentifrices are the most common vehicles for active ingredients used for DH treatment. The aim of this study was to evaluate the efficacy of three toothpastes on dentinal tubule occlusion, mineral acquisition, and dentin hardness. Forty human dentin disks were submerged in 40% citric acid for 30 s and then exposed to tooth brushing for 2 min twice a day for 14 days using three toothpastes: Dontodent Sensitive (group 1), Dr. Wolff's Biorepair (group 2), and Sensodyne Repair and Protect (group 3). In the control group (group 4), the samples were brushed with water. All of the samples were evaluated using scanning electron microscopy (SEM), energy-dispersive X-ray (EDX), and Vickers dentin hardness determination. On SEM images, the degree of dentinal tubule occlusion was assessed using a five-grade scale. The mean score values in groups 1-4 were 3.60 ± 0.69, 2.20 ± 0.91, 2.30 ± 1.16, and 5.00 ± 0.00, significantly higher in study groups when compared to the control group (Kruskal Wallis test p < 0.05). EDX evaluation showed significantly higher calcium and phosphorus concentrations in groups 1 and 3 when compared to control group d. The mean values of Vickers dentin hardness numbers in groups 1-4 were 243.03 ± 10.014, 327.38 ± 56.65, 260.29 ± 37.69, and 225.83 ± 29.93, respectively. No statistically significant results were obtained when comparing the hardness mean values in groups (Kruskal-Wallis statistical test, p = 0.372 > 0.05). All three toothpastes tested demonstrated significant occlusion of dentinal tubules. Dontodent Sensitive and Sensodyne Repair and Protect toothpastes enhanced the calcium and phosphorus content of the dentin surface. None of the toothpastes increased dentin hardness as a result of mineral acquisition.

Microscopic aspects of junction between dental hard tissues and composite material depending on composite insertion: layering versus bulk-fill.

Polymerization stresses in adhesive structure could determine an adhesive or cohesive failure and interfacial gaps forming. Some clinical procedures - as light curing composite resin layering in 2-3 mm increments (especially for dental fills) or using dental reconfiguring clear acetate crowns - are sat up to combat (in some way) the polymerization shrinkage. This study approaches the manner how clinical dental adhesive application could influence the hard dental tissues-composite materials interface. The sample studied consisted of 12 upper bicuspids, extracted for orthodontic reasons. In our study, we chose the adhesion technique in "two steps". We prepared enamel and dentine areas, and then filled them with light-polymerization composite. After that, the teeth were subject of microscopic investigations, at 100× and 200× magnification. As conclusion of our study, we sustain that light curing composite resin applying clinical technique (by layering or with acetate crown) might influence a good dental restoration clinical performance.

Morphological study of upper wisdom tooth.

The article presents aspects of crown and root morphology of the superior wisdom teeth, aiming to several parameters: size, shape crown and occlusal surface, number, topography and orientation of the roots in order to determine which the most common morphological types are. For this purpose, the upper wisdom teeth were collected. According to studies, the dominant form of the dental crown is parallelepipedic, the rectangular or parallelogram shape of the occlusal surface has large mesial and distal-oriented sides. The positive occlusal forms are generally poorly demarcated; cusps are less tall and rarely individualized. In half of the cases, the root is unique, voluminous, straight or with a curved distal tip.