Clinical and Patient-reported Outcomes of a Zirconia Oral Implant: Three-year Results of a Prospective Cohort Investigation.

The objective of this study was to determine the clinical, radiographic, and patient-reported outcomes of a 1-piece alumina-toughened zirconia implant restored with single crowns (SCs) or 3-unit fixed dental prostheses (FDPs) after 3 y of observation. Forty patients received 53 implants, placed in a 1-stage operation with immediate temporization. Finally, 50 implants were restored with 24 SCs and 13 FDPs. To evaluate peri-implant bone loss, standardized radiographs were taken at implant insertion, at final restoration delivery, and after 1 and 3 y. Additionally, several soft tissue parameters and patient-reported outcome measures were evaluated. Linear mixed models with random intercept for each patient and patients as clusters were used to compare subgroups. Three patients did not receive a SC due to early implant loss, and 1 patient died. As a result, 36 patients with 49 implants were followed-up for 3 y, giving a cumulative survival rate of 94.2%. The average marginal bone loss amounted to 0.79 mm (SCs, 0.47 mm; FDPs, 1.07 mm; P < 0.001). After the delivery of the final prosthetic restoration, further bone loss was not statistically significant (0.09 mm; P = 0.700). Probing depth, clinical attachment level, and modified bleeding index increased significantly at the implant sites, whereas gingival recession decreased significantly. Compared with the pretreatment questionnaires, the patient-reported outcome measures showed a permanently improved perception of function, aesthetics, sense, speech and self-esteem. The survival rate of the investigated ceramic implant system seems to be comparable to reported survival rates of titanium implants when immediately restored. The recorded parameters suggest its potential for clinical utilization.

The use of cone beam computed tomography to predetermine root canal lengths in molar teeth: a comparison between two-dimensional and three-dimensional measurements.

OBJECTIVES: The aim of this study was to evaluate the accuracy of two-dimensional (2D) and three-dimensional (3D) root canal length measurements in molar teeth using cone beam computed tomography (CBCT). MATERIALS AND METHODS: Root canal lengths of twenty molar teeth were measured with two different CBCT approaches. After adjusting the CBCT images, 2D measurements were performed within the sagittal plane between the apical foramen and the coronal reference (cusp). The 3D approach measured centrically in axial planes. A linear mixed model with random intercepts was fitted to compare differences between methods (2D and 3D). The correlation between CBCT measurements and the actual root canal length was evaluated using the Pearson correlation coefficient. RESULTS: Differences between 3D measurements and the actual root canal lengths were significantly smaller compared to the 2D approach (p < 0.001). Mean differences were 0.32 and 0.58 mm, respectively. A high correlation was found between the actual root canal length and 3D measurements (Pearson correlation coefficient = 0.97). Compared to the actual root canal length, 80 % of the 3D measurements were within the limits of ±0.5 mm. CONCLUSIONS: 3D measurements of root canals in molar teeth are more accurate than simple 2D measurements and show a high correlation to the actual lengths. CLINICAL RELEVANCE: In cases where a CBCT is already available, root canal lengths in molar teeth can be accurately predetermined using a standardized 3D approach.