Objective: The aim of this study was to investigate the root and canal morphology of mandibular first and second molars in a Turkish population by using cone beam computed tomography (CBCT). Study design: CBCT images of mandibular first (n = 823) and second molar (n = 925) teeth from 605 Turkish patients were analyzed. The root canal configurations were classified according to the method of Vertucci. Results: The majority of mandibular molars (95.8% of first molars, 85.4% of second molars) had two separate roots; however, three roots were identified in 2.06% of first molars and 3.45% of second molars. C-shaped canals occurred 0.85% of first molars and 4.1% of second molars. Three canals were found in 79.9% of first molars and 72.8% of second molars. Most distal roots had a simple type I configuration, whereas mesial roots had more complex canal systems, with more than one canal. The most common root morphology of first and second molars is the two rooted morphology with three canals. Both the mesial and distal roots showed wide variations in canal anatomy with type IV and type I canal configuration predominating in the mesial and distal roots, respectively. Conclusion: Vertucci type I and IV canal configurations were the most prevalent in the distal and mesial roots, respectively, of both the mandibular first and second permanent molar teeth. Key words:Cone-beam CT, Turkish, mandibular molars, root and canal morphology.

ObjectivesTo assess the incidence of postoperative pain after single- and multi-visit endodontic treatment of teeth with vital and non-vital pulp.MethodsIn total, 306 patients with teeth requiring endodontic treatment were identified and were included in this study. Two experienced clinicians treated the patients, who were randomly assigned to two groups. While the teeth of patients in group 1 were obturated, group 2 were temporarily sealed and obturated after one week. Three days after the root canal instrumentation of each tooth, the patients were asked whether they experienced any postoperative pain and to rate the level of discomfort as no, mild, moderate, or severe pain. Data were analyzed statistically using the chi-square test.ResultsNo significant difference in postoperative pain was found between vital and non-vital teeth (P>.01). Mild, moderate, and severe pain occurred in 31.4, 13.7, and 4.6% of vital teeth, respectively. Postoperative pain occurred in 107 (69.9%) and 106 (69.3%) teeth in the single- and multi-visit treatment groups, respectively. There was no significant difference in postoperative pain between the two groups (P>.01).ConclusionsThe prevalence of postoperative pain did not differ between vital and non-vital teeth. The majority of patients in either groups reported no or only mild pain.

ObjectiveTo study and compare the effects of different demineralization-inhibition methods on the shear bond strength (SBS) and fracture mode of an adhesive used to bond orthodontic brackets to demineralized enamel surfaces.MethodsEighty freshly extracted, human maxillary premolars were divided into 4 equal groups and demineralized over the course of 21 days. Brackets were bonded to the demineralized enamel of teeth in Group 1. In Group 2, bonding was performed following resin infiltration (ICON®, DMG, Hamburg, Germany). Before bonding, pre-treatment with acidulated phosphate fluoride (APF) or solutions containing casein phosphopeptide-amorphous calcium phosphate with 2% neutral sodium fluoride (CPP-ACP/wF) was performed in Groups 3 and 4, respectively. The SBS values of the brackets were measured and recorded following mechanical shearing of the bracket from the tooth surface. The adhesive remnant index (ARI) scores were determined after the brackets failed. Statistical comparisons were performed using one-way ANOVA, Tukey's post-tests, and G-tests.ResultsSignificant differences were found in some of the intergroup comparisons of the SBS values (F = 39.287, p < 0.001). No significant differences were found between the values for the APF-gel and control groups, whereas significantly higher SBS values were recorded for the resin-infiltrated and CPP-ACP/wF-treated groups. The ARI scores were also significantly different among the 4 groups (p < 0.001).ConclusionsTooth surfaces exposed to resin infiltration and CPP-ACP/wF application showed higher debonding forces than the untreated, demineralized surfaces.

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The aim of this study was to evaluate and compare the effects of resin infiltration and sealant type on enamel surface properties and Streptococcus mutans adhesion to artificial enamel lesions. Artificial enamel lesions were produced on the surfaces of 120 enamel specimens, which were divided into two groups: Group A and Group B (n=60 per group). Each group was further divided into four subgroups (n=15 per subgroup) according to sealant type: Group I-Demineralized enamel (control); Group II-Enamel Pro Varnish; Group III-ExciTE F; and Group IV-Icon. In Group A, hardness and surface roughness were evaluated; in Group B, bacterial adhesion was evaluated. Icon application resulted in significantly lower surface roughness and higher hardness than the other subgroups in Group A. In Group B, Enamel Pro Varnish resulted in lowest bacterial adhesion, followed by Icon. This study showed that resin infiltration of enamel lesions could arrest lesion progress.