Clinical Outcomes After Immediate and Late Implant Loading for a Single Missing Tooth in the Anterior Maxilla.

PURPOSE: This study compared the clinical outcomes of 1-year follow-up of immediate and late implant loading after implant restoration of a single tooth in the anterior maxilla. MATERIALS AND METHODS: Thirty-three patients with missing teeth in the anterior maxilla were included in this study (18 immediate loading and 15 late loading). Standard periapical radiographs were obtained to evaluate the vertical bone loss around the implant. For both implant groups, periimplant parameters (probing depth, gingival bleeding index, gingival index (GI), modified plaque index, width of keratinized gingiva) were evaluated. RESULTS: There were no significant differences in bone loss, the widths of keratinized gingiva, the GI, and modified plaque index between the immediate implant loading and late implant loading groups (P > 0.05). A significant difference in the probing depth was observed between these groups at the initial and 1-month evaluations (P < 0.05). Significant differences in bleeding indices between these groups were observed at months 3 and 6 (P < 0.05). CONCLUSIONS: When selecting appropriate patients (adequate primary stability, patient compliance with the surgeon's recommendations), immediate implant loading may be an alternative method to late loading protocol for replacement of a missing tooth in anterior maxilla.

Effect of fluid contamination on reverse torque values in bone-level implants.

INTRODUCTION: Screw loosening is one of the most common mechanical complications within the prosthetic components of dental implants. Clinicians must know if reverse torque values (RTVs) are affected by contamination of the implant abutment screw hole with either blood, saliva or chlorhexidine. METHODS: Forty implants were divided into 4 groups (n = 10). Implants were embedded in epoxy resin and placed in a digital torque meter. Screw holes of 30 implants were contaminated with either chlorhexidine (CG), fresh human saliva (SG), or blood (BG), and the remaining noncontaminated screws served as a control group (NC). Abutment screws were tightened using a hand-held torque meter (25 N·cm). Thermocycling (1500 cycles) was performed, and abutment detorque values were calculated using the digital torque meter. RESULTS: RTVs were lower than insertion torque values for all groups. According to Tukey HSD Test, blood contamination of abutment screws resulted in significantly lower RTVs (18.950 ± 2.641 N·cm) when compared with controls. CONCLUSIONS: Blood contamination of abutment screw holes was shown to significantly decrease RTVs. Blood contamination may result in greater loosening of implant screws in clinical practice.

Effects of metal surface grinding at the porcelain try-in stage of fixed dental prostheses.

PURPOSE: This study was to evaluate the effect of grinding of the inner metal surface during the porcelain try-in stage on metal-porcelain bonding considering the maximum temperature and the vibration of samples. MATERIALS AND METHODS: Ninety-one square prism-shaped (1 × 1 × 1.5 mm) nickel-chrome cast frameworks 0.3 mm thick were prepared. Porcelain was applied on two opposite outer axial surfaces of the frameworks. The grinding was performed from the opposite axial sides of the inner metal surfaces with a low-speed handpiece with two types of burs (diamond, tungsten-carbide) under three grinding forces (3.5 N, 7 N, 14 N) and at two durations (5 seconds, 10 seconds). The shear bond strength (SBS) test was performed with universal testing machine. Statistical analyzes were performed at 5% significance level. RESULTS: The samples subjected to grinding under 3.5 N showed higher SBS values than those exposed to grinding under 7 N and 14 N (P<.05). SBS values of none of the groups differed from those of the control group (P>.05). The types of bur (P=.965) and the duration (P=.679) did not affect the SBS values. On the other hand, type of bur, force applied, and duration of the grinding affected the maximum temperatures of the samples, whereas the maximum vibration was affected only by the type of bur (P<.05). CONCLUSION: Grinding the inner metal surface did not affect the metal-porcelain bond strength. Although the grinding affected the maximum temperature and the vibration values of the samples, these did not influence the bonding strength.