Increasing the Vertical Dimension of Occlusion: A Multicenter Retrospective Clinical Comparative Study on 100 Patients with Fixed Tooth-Supported, Mixed, and Implant-Supported Full-Arch Rehabilitations

This multicenter retrospective clinical study was aimed at comparing the effects of an increase in vertical dimension of occlusion (VDO) in patients with fixed rehabilitations. Expert clinicians retrospectively evaluated 100 patients treated with an increase of the VDO and fixed dental prostheses (FDPs) supported by teeth, implants, or both. The patients were divided into three study groups according to the type of support of restorations in posterior areas, as follows: partially edentulous patients with posterior teeth-supported rehabilitations and no implants in posterior segments (group A), partially edentulous patients with posterior mixed rehabilitations and at least one osseointegrated implant in posterior segments (group B), and completely edentulous patients with posterior implant-supported rehabilitations (group C). The new VDO was tested with mock-ups, temporary restorations, or removable appliances. The patients were followed up for at least 1 year after the delivery of final restorations. Clinical variables were collected retrospectively, such as presence of referred self-reported bruxism and temporomandibular joint or muscle symptoms before treatment, extension of the dental arches, increase in VDO, restorative materials, and functional complications. Descriptive statistics were analyzed; the three experimental groups were compared with one-way analysis of variance (ANOVA) followed by Tukey post hoc test for the quantitative variables and with logistic regression using the likelihood ratio test for the qualitative variables. Statistically significant differences were reported among the experimental groups for functional complications. Functional and prosthetic complications after the VDO increase were not frequent. Functional complications were mainly noticed in group C but usually were no longer evident after 2 weeks. No significant differences were found between groups in terms of prosthetic complications and self-reported bruxism

Internal- vs external-connection single implants: A retrospective study in an italian population treated by certified prosthodontists

Purpose: The design of an implant connection that allows prosthetic suprastructures to be attached to implants has long been debated in the dental literature. The goal of this retrospective study was to evaluate the 5-year clinical results for a large number of single implants restored by certified prosthodontists in an attempt to establish whether different clinical outcomes could be detected for external- or internalconnection implants. Materials and Methods: All single implants with internal or external connections inserted in 27 private dental practices from January 1, 2003 to December 31, 2007 were evaluated. An initial statistical analysis was performed to describe the sample population at baseline and then to compare the two types of implant-abutment connection configurations and their clinical outcomes. All data were statistically analyzed with STATA12 (StataCorp). Results: Twenty-eight of the 85 active members of the Italian Academy of Prosthetic Dentistry (AIOP) participated in this study. The sample included 1,159 patients and 2,010 implants. Of the implants, 75 were dropped because there was no information about follow-up. Of the remaining implants, 1,431 (74.0%) were followed for at least 5 years, and 332 implants (17.2%) were followed for more than 8 years. Nearly 99% (98.9%) of the implants survived. The difference between the survival frequencies of the two types of implant-abutment connection configurations was not significant for each negative event (log-rank test, P > .05). There was no difference between the two types of implants regarding restoration fracture, implant screw loosening, and peri-implant disease. Conclusion: Within the limitations of this study, it can be suggested that there is no difference in clinical outcomes of single restorations joined to internal- or external-connection implants