Soft tissue cell adhesion to titanium abutments after different cleaning procedures: preliminary results of a randomized clinical trial

Objectives: A randomized controlled trial was performed to assess soft tissue cell adhesion to implant titanium abutments subjected to different cleaning procedures and test if plasma cleaning can enhance cell adhesion at an early healing time. Study Design: Eighteen patients with osseointegrated and submerged implants were included. Before re-opening, 18 abutments were divided in 3 groups corresponding to different clinical conditions with different cleaning processes: no treatment (G1), laboratory customization and cleaning by steam (G2), cleaning by plasma of Argon (G3). Abutments were removed after 1 week and scanning electron microscopy was used to analyze cell adhesion to the abutment surface quantitatively (percentage of area occupied by cells) and qualitatively (aspect of adhered cells and presence of contaminants). Results: Mean percentages of area occupied by cells were 17.6 ± 22.7%, 16.5 ± 12.9% and 46.3 ± 27.9% for G1, G2 and G3 respectively. Differences were statistically significant between G1 and G3 (p=0.030), close to significance between G2 and G3 (p=0.056), and non-significant between G1 and G2 (p=0.530). The proportion of samples presenting adhered cells was homogeneous among the 3 groups (p-valor = 1.000). In all cases cells presented a flattened aspect; in 2 cases cells were less efficiently adhered and in 1 case cells presented filipodia. Three cases showed contamination with cocobacteria. Conclusions: Within the limits of the present study, plasma of Argon may enhance cell adhesion to titanium abutments, even at the early stage of soft tissue healing. Further studies with greater samples are necessary to confirm these findings

Comparison Between Conventional Milling and a Novel Hybrid Manufacturing Technology

Objectives: Poor fit at the framework-implant interface increases the strain and stress within both the framework and the surrounding tissues. The primary aim of this study was to compare the accuracy and precision (repeatability) of the selective laser melting/milling hybrid technology (SLM/m) with that of conventional milling to manufacture implant-supported frameworks for full-arch oral rehabilitation on implants. Methods: A computer model of a six-implant-supported full-arch framework was used to manufacture a total of 27 titanium clones by three independent manufacturing centres (9 specimens for each lab) using hybrid SLM/m technology (Lab 1 and Lab 2), or the conventional milling technique (Lab 3). Measurements of the accuracy, precision and inter-distance error were performed using a metrological approach with an opto-mechanical coordinate-measuring machine (OCMM). Results: The accuracy analysis of 3D error among framework connecting platform (FCP) position showed significant differences (Multilevel analysis) between Lab 3 and both Lab 1 (p=0.007) and Lab 2 (p=0.039); no significant difference was detected between Lab 1 and 2 (hybrid technology). The precision (repeatability) analysis of variance within each laboratory showed no significant differences within laboratories (Multilevel analysis, p > 0.05), suggesting good within-laboratory repeatability. However, significant differences in repeatability were observed among laboratories (p<0.01). The effect of FCP inter-distance magnitude on framework accuracy confirmed that the absolute distance error within paired FCP increases when the distance increases. Conclusions: All labs showed 3D misfits well within the error limits reported in the literature. Regarding accuracy, a significant difference was seen between the SLM/m and milling technologies. Regarding precision, repeatability was consistent within each lab, but a significant difference was detected among laboratories. Moreover, the absolute error increased as the inter-distance of paired FCP increased

Clinical evaluation of 1,132 zirconia-based single crowns: A retrospective cohort study from the aiop clinical research group

Purpose: The aim of this retrospective cohort study was to gather the outcomes of zirconia single crowns made by 16 members of the Italian Academy of Prosthetic Dentistry (AIOP) over a time period of up to 5 years. Materials and Methods: A total of 398 patients treated in private practices with 1,132 zirconia-based single-crown restorations made on natural teeth from January 2005 to July 2010 were included. Three hundred forty-three anterior restorations (30.3%) and 789 posterior crowns (69.7%) were made with 16 types of zirconia, using primarily chamfer or knife-edge tooth preparation, and examined according to the esthetic, functional, and biologic criteria. To evaluate the relationship of parafunction with mechanical failure, patients with clenching or bruxism were not excluded from the study group. Results: The cumulative survival rate of all restorations was 98.1%, while the cumulative success rate was 94.3%. Functional criteria had the highest number of failures. The odds ratio (OR) for all restorations was calculated to clarify the relationship between patients who were subject/not subject to parafunctions and technical complications; the OR was 2.60. An association between parafunction and mechanical failure was found in patients with severe parafunction. Conclusions: Porcelain-veneered zirconia single crowns with chamfer and knife-edge preparations showed good clinical results over a period of up to 5 years. Technical complications were few and were limited primarily to patients with parafunction. © 2013 by Quintessence Publishing Co Inc

Clinical evaluation of zirconia-based restorations on implants: a retrospective cohort study from the AIOP clinical research group.

The aim of this retrospective cohort study was to evaluate the clinical performance of zirconia-based implant-supported single crowns and fixed dental prostheses (FDPs) made by 15 members of the Italian Academy of Prosthetic Dentistry (AIOP) over a time period of up to 5 years. MATERIALS AND METHODS: One hundred thirty-one patients were treated with a total of 210 zirconia-based single crowns and FDPs on implants in anterior and posterior regions. A cohort group with parafunctional habits was compared with patients without parafunctional habits according to the esthetic, functional, and biologic United States Public Health Service criteria modified by the FDI World Dental Federation. RESULTS: The estimated cumulative survival (ECS) and standard error (SE) of all restorations on implants was 91.95% \ub1 1.39%, and the estimated cumulative success (ECSs) and SE was 88.37% \ub1 1.72%. The ECS of single crowns and FDPs was 91.25% \ub1 3.69% and 95.23% \ub1 2.28%, respectively, and the estimated cumulative success rates were 88.84% \ub1 2.05% and 87.96% \ub1 3.16%, respectively. Mechanical failures, including four zirconia core fractures, three hairline cracks, four chippings, and five delaminations of the ceramic veneering material, were recorded during a 1- to 5-year observation period. The odds ratio of 3.39 (95% confidence interval: 1.18 to 9.73) showed a moderate association between parafunction and failure. CONCLUSIONS: Zirconiabased implant-supported restorations showed encouraging clinical results over a period of up to 5 years, but more clinical data are needed before these restorations can be considered a viable treatment alternative. Mechanical failures were primarily observed in patients with parafunctions

Clinical evaluation of tooth-supported zirconia-based fixed dental prostheses: A retrospective cohort study from the AIOP clinical research group

Purpose: The aim of this retrospective cohort study was to evaluate the clinical performance of tooth-supported zirconia-based fixed dental prostheses (FDPs) made by 15 members of the Italian Academy of Prosthetic Dentistry over a time period of up to 5 years. Materials and Methods: Ninety-eight patients were treated with a total of 137 zirconia-based FDPs in anterior and posterior regions using primarily chamfer or knife-edge tooth preparations. The cohort group with parafunctional habits was compared with patients without parafunctional habits according to the esthetic, functional, and biologic United States Public Health Service criteria modified by the FDI World Dental Federation. Results: The estimated cumulative survival of all restorations was 94.70% \ub1 1.25% standard error (SE), whereas the estimated cumulative success decreased to 89.78% \ub1 2.58 SE. Mechanical failures, including three zirconia framework fractures, two hairline cracks, nine chippings, and one delamination of the ceramic veneering, were recorded during the 1-to 5-year observation period. An odds ratio of 2.02 (95% confidence interval: 0.67 to 6.12) showed a moderate association between parafunction and failure. Conclusions: Zirconia-based tooth-supported FDPs showed promising clinical results over a period of up to 5 years. Technical complications were more commonly detected in patients with parafunctional habits

Clinical evaluation of zirconia-based restorations on implants: A retrospective cohort study from the AIOP clinical research group

Purpose: The aim of this retrospective cohort study was to evaluate the clinical performance of zirconia-based implant-supported single crowns and fixed dental prostheses (FDPs) made by 15 members of the Italian Academy of Prosthetic Dentistry (AIOP) over a time period of up to 5 years. Materials and Methods: One hundred thirtyone patients were treated with a total of 210 zirconia-based single crowns and FDPs on implants in anterior and posterior regions. A cohort group with parafunctional habits was compared with patients without parafunctional habits according to the esthetic, functional, and biologic United States Public Health Service criteria modified by the FDI World Dental Federation. Results: The estimated cumulative survival (ECS) and standard error (SE) of all restorations on implants was 91.95% \ub1 1.39%, and the estimated cumulative success (ECSs) and SE was 88.37% \ub1 1.72%. The ECS of single crowns and FDPs was 91.25% \ub1 3.69% and 95.23% \ub1 2.28%, respectively, and the estimated cumulative success rates were 88.84% \ub1 2.05% and 87.96% \ub1 3.16%, respectively. Mechanical failures, including four zirconia core fractures, three hairline cracks, four chippings, and five delaminations of the ceramic veneering material, were recorded during a 1-to 5-year observation period. The odds ratio of 3.39 (95% confidence interval: 1.18 to 9.73) showed a moderate association between parafunction and failure. Conclusions: Zirconiabased implant-supported restorations showed encouraging clinical results over a period of up to 5 years, but more clinical data are needed before these restorations can be considered a viable treatment alternative. Mechanical failures were primarily observed in patients with parafunctions

Clinical evaluation of 1132 zirconia-based single crowns: a retrospective cohort study from the AIOP clinical research group.

PURPOSE: The aim of this retrospective cohort study was to gather the outcomes of zirconia single crowns made by 16 members of the Italian Academy of Prosthetic Dentistry (AIOP) over a time period of up to 5 years. MATERIALS AND METHODS: A total of 398 patients treated in private practices with 1,132 zirconia-based single-crown restorations made on natural teeth from January 2005 to July 2010 were included. Three hundred forty-three anterior restorations (30.3%) and 789 posterior crowns (69.7%) were made with 16 types of zirconia, using primarily chamfer or knife-edge tooth preparation, and examined according to the esthetic, functional, and biologic criteria. To evaluate the relationship of parafunction with mechanical failure, patients with clenching or bruxism were not excluded from the study group. RESULTS: The cumulative survival rate of all restorations was 98.1%, while the cumulative success rate was 94.3%. Functional criteria had the highest number of failures. The odds ratio (OR) for all restorations was calculated to clarify the relationship between patients who were subject/not subject to parafunctions and technical complications; the OR was 2.60. An association between parafunction and mechanical failure was found in patients with severe parafunction. CONCLUSIONS: Porcelain-veneered zirconia single crowns with chamfer and knife-edge preparations showed good clinical results over a period of up to 5 years. Technical complications were few and were limited primarily to patients with parafunctio

Clinical evaluation of tooth-supported zirconia-based fixed dental prostheses: a retrospective cohort study from the AIOP clinical research group

The aim of this retrospective cohort study was to evaluate the clinical performance of tooth-supported zirconia-based fixed dental prostheses (FDPs) made by 15 members of the Italian Academy of Prosthetic Dentistry over a time period of up to 5 years. MATERIALS AND METHODS: Ninety-eight patients were treated with a total of 137 zirconia-based FDPs in anterior and posterior regions using primarily chamfer or knife-edge tooth preparations. The cohort group with parafunctional habits was compared with patients without parafunctional habits according to the esthetic, functional, and biologic United States Public Health Service criteria modified by the FDI World Dental Federation. RESULTS: The estimated cumulative survival of all restorations was 94.70% \ub1 1.25% standard error (SE), whereas the estimated cumulative success decreased to 89.78% \ub1 2.58 SE. Mechanical failures, including three zirconia framework fractures, two hairline cracks, nine chippings, and one delamination of the ceramic veneering, were recorded during the 1- to 5-year observation period. An odds ratio of 2.02 (95% confidence interval: 0.67 to 6.12) showed a moderate association between parafunction and failure. CONCLUSIONS: Zirconia-based tooth-supported FDPs showed promising clinical results over a period of up to 5 years. Technical complications were more commonly detected in patients with parafunctional habits

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