A 5 to 7-year case series on single angulated implants installed following papilla-sparing flap elevation

BACKGROUND

Bony concavities at the buccal aspect may cause a distortion between the implant axis and ideal prosthetic axis. Angulated implants can overcome this problem, yet long-term data are lacking. In addition, papilla-sparing incisions have been proposed to reduce tissue loss, yet aesthetic outcomes have not been published.

PURPOSE

To evaluate the 5 to 7-year outcome of single angulated implants installed following papilla-sparing flap elevation.

MATERIALS AND METHODS

Patients who had been consecutively treated with a single angulated implant (Co-axis®, Southern Implants, Irene, South Africa) in the anterior maxilla were re-examined after 5 to 7 years. Available data at 1 year (T1) were compared to those obtained at 5 to 7 years (T2).

RESULTS

Twenty out of 22 treated patients (11 females, 9 males, mean age of 52) with 22 implants attended the 5 to 7-year reassessment. All implants survived and stable clinical conditions could be reached with mean marginal bone loss of 1.28 mm at T2. Papilla-sparing flap elevation resulted in Pink Esthetic Score of 9.83 at T1 and 8.23 at T2 (p = 0.072). Mucosal Scarring Index was 4.61 at T1 and 3.50 at T2 (p = 0.165). The overall appearance of scarring significantly improved over time (p = 0.032), yet 59% of the cases still demonstrated scarring at T2.c CONCLUSIONS: Within the limitations of the study, angulated implants (Co-axis®, Southern Implants) reached stable clinical conditions. Papilla-sparing incisions may not be recommended in aesthetically demanding patients due to high risk of scarring.

Three-Dimensional Accuracy of Conventional Versus Digital Complete Arch Implant Impressions

PURPOSE

The accuracy of digital impressions is still controversial for complete arch implant cases. The aim of this study is to compare the accuracy of different intraoral scanners with the conventional technique in terms of trueness and precision in a complete arch implant model.

MATERIAL AND METHODS

Eight implants were inserted asymmetrically in a polyurethane edentulous mandibular model with different angulations. A 3-dimensional (3D) reference model was obtained by scanning this polyurethane model with an optical scanner. First, digital impressions were made by using 3 different intraoral scanners: Carestream 3500 (DC), Cerec Omnicam (DO) and 3Shape Trios 3 (DT). Subsequently, a nonsplinted open tray impression technique was used for conventional impression group (C) and then the master casts were digitalized with a lab scanner. Each 10 STL files belonging to 4 different impression groups were imported to a reverse engineering program, to measure distance and angle deviations from the reference model. All statistical analyses were performed after taking absolute values of the data. After comparing the impression groups with one-way ANOVA, the trueness and precision values were analyzed by Tukey post hoc test and 0.05 was used as the level of significance.

RESULTS

The mean trueness of distance was 123.06 ± 89.83 µm for DC, 229.72 ± 121.34 µm for DO, 209.75 ± 47.07 µm for DT, and 345.32 ± 75.12 µm for C group (p < 0.0001). While DC showed significantly lower deviation compared to DO and C, no significant difference was found between DC and DT. C showed the highest distance deviation significantly in all groups; and no significant difference was found between DO and DT groups. In angle measurements; the trueness was 0.26° ± 0.07° for DC, 0.53° ± 0.42° for DO, 0.33° ± 0.30° for DT, and 0.74° ± 0.65° for C group. There was no significant difference between the groups in terms of angular trueness (p = 0.074). In terms of the precision for distance, the results of DC 80.43 ± 29.69 µm, DO 94.06 ± 69.96 µm, DT 35.55 ± 28.46 µm and C 66.97 ± 36.69 µm were determined (p = 0.036). The significant difference was found only between DT and DO among all groups. Finally, angular precision was determined to be 0.19° ± 0.11° for DC, 0.30° ± 0.28° for DO, 0.22° ± 0.19° for DT, and 0.50° ± 0.38° for Group C. No significant difference was found between the groups, in terms of angular precision (p = 0.053).

CONCLUSIONS

All digital impression groups yielded superior data compared to conventional technique in terms of trueness. DC formed the impression group with the highest trueness in both distance and angular measurements. The results of this in vitro study suggest the use of intraoral scanners compared to the conventional impression techniques in complete arch implant cases with high angulations.