Helena Francisco

Effects of diabetes mellitus on salivary secretion and its composition in the human

This study investigated the effects of diabetes mellitus (types I and II) on human salivary gland function compared to healthy age-matched controls. The results have shown that both type I and type II diabetic patients secrete significantly (p < 0.05) less resting and stimulated saliva compared to healthy age-matched controls (AMC). It was also found that the diabetic patients have an increased resting and stimulated salivary protein concentration compared to healthy participants. However, the secretory capacity (stimulated minus resting values) was markedly reduced compared to controls. The level of calcium (Ca2+) in the saliva of diabetic patients was significantly (p < 0.05) elevated compared to the AMC. In contrast, the levels of magnesium (Mg2+), zinc (Zn2+) and potassium (K+) in the saliva of diabetic patients were significantly (p < 0.05) reduced compared to the values obtained in AMC. These results indicate that diabetes mellitus can lead to marked dysfunction of the secretory capacity of the salivary glands. In these patients a modified fluid, organic and inorganic salivary secretion may be responsible for the increased susceptibility to oral infections and impaired wound healing described by others in the literature. (Mol Cell Biochem 261: 137–142, 2004)

Prevalence of C-shaped Configurations in the Mandibular First and Second Premolars: A Cone-beam Computed Tomographic In Vivo Study

Introduction The mandibular premolar C‐shaped anatomy has been presented as a complex morphology to be treated. The objective of this retrospective observational study was to evaluate and characterize, in in vivo conditions, the incidence of these morphologies using cone‐beam computed tomographic (CBCT) technology. Methods Mandibular premolar CBCT samples were collected from a preexisting database. All teeth were analyzed in 3 planes (axial, coronal, and sagittal), and the C‐shape classification was performed at 3 different axial levels (coronal, middle, and apical). C‐shape presence and configuration were recorded as well as the number of roots, the presence of a radicular groove, and Vertucci classification. The Z test for proportions was used to analyze the differences between independent groups. Intraobserver reliability was tested using the Cohen kappa test. Results Two thousand twelve mandibular premolars were included in this study. A prevalence of C‐shaped morphologies was noted in 2.3% and 0.6% of mandibular first and second premolars, respectively. This clinical condition was mostly unilateral. The C‐shaped configuration (C1 and C2) was found mainly in the middle axial level. Its presence was uncommon in the apical level and null in the coronal level; 61.5% of all mandibular first premolar C shapes were identified in Vertucci type V roots. Differences were observed among sex, teeth, and Vertucci root configuration at P < .05. Conclusions Although the mandibular premolar C‐shaped anatomy has a low prevalence ratio, a clinician should be aware of its existence, mainly when treating roots with Vertucci type V configuration. The prevalence was statistically higher in first premolars and males.

Ceramic-Veneered Zirconia Frameworks in Full-Arch Implant Rehabilitations: A 6-Month to 5-Year Retrospective Cohort Study.

PURPOSE This was a retrospective cohort study designed to evaluate the clinical performance of ceramic-veneered zirconia frameworks. MATERIALS AND METHODS Patients were recruited according to defined inclusion criteria. All patients were checked every 4 months from the time of definitive rehabilitation. At the end of 2013, all patients were rescheduled and rechecked for study purposes. The restorative procedures assessment was performed by previously established methods. The primary outcomes were the survival and success rates of the prosthesis. Descriptive statistics were used for the patients demographics, implant distribution, and occurrence of complications. To study the survival and success of the prostheses, a Cox Regression analysis was used with a model constructed in a forward conditional stepwise mode. Predictive variables were included in the model, and adjusted survival curves were obtained for each outcome. RESULTS From 2008 to 2013, 75 patients were rehabilitated with 92 implant-supported, screw-retained, full-arch ceramic-veneered zirconia framework rehabilitations. The range of follow-up was between 6 months and 5 years. From the 92 full implant-supported screw-retained full-arch rehabilitations, Cox regression analysis indicated that within a 5-year time frame, the probability of framework fracture, major chipping, minor chipping, or any of the former combined to occur was 17.6%, 46.5%, 69.2%, and 90.5%, respectively. CONCLUSION Results suggest zirconia as a suitable material for framework structure in implant-supported, full-arch rehabilitations. However, it experiences a high incidence of technical complications, mainly due to ceramic chipping. Further clinical studies should aim to ascertain the effects of clinical features and manufacturing procedures on the survival rates of these prostheses.

Differences on the Root and Root Canal Morphologies between Asian and White Ethnic Groups Analyzed by Cone-beam Computed Tomography

Introduction: Populations from different geographic regions and ethnic backgrounds may present differences in dental morphology. The aim of this study was to compare the differences in root and root canal configurations on Asian and white subpopulations using cone‐beam computed tomographic imaging. Methods: Information from Asian and white patients was retrieved from 2 cone‐beam computed tomographic imaging databases in China and Western Europe. Two calibrated observers collected data regarding the number of roots and Vertucci root canal system configuration for all groups of teeth. A total of 15,655 teeth were analyzed. The z test for independent groups was used to analyze differences between the groups. The significance level was considered at a P value < .05. Reliability tests were performed between observers. Results: Differences were noted in the number of roots per tooth in 6 groups of teeth. The Asian group showed a higher prevalence of single‐root configurations in maxillary first premolars (83.2%) and mandibular second molars (45.4%) when compared with whites with 48.7% and 14.3%, respectively. Moreover, 3‐rooted configurations in mandibular first molars were more common in Asians (25.9%) compared with whites (2.6%). Seventeen of the 20 analyzed roots had a higher prevalence of Vertucci type I configuration in Asians. Maxillary first molars with second mesiobuccal root canals were more commonly found in whites than in Asians (71.3% and 58.4%, respectively). A similar situation was found in maxillary second molars. Conclusions: The Asian ethnic group presented a higher prevalence of Vertucci type I configuration, whereas the white group displayed a higher number of multiple root canal system morphologies. A clinician should be aware of these differences when treating patients from these ethnic groups.