Esthetic Evaluation of Anterior Single-Tooth Implants with Different Abutment Designs-Patients' Satisfaction Compared to Dentists' Observations.

PURPOSE: To correlate patients' satisfaction and dentists' observations regarding two abutment designs used for single crowns in the esthetic zone: a divergent one (control) and a curved one (experimental), with special emphasis on muco-gingival esthetics. MATERIALS AND METHODS: Twenty-six patients with nonadjacent missing teeth in the esthetic zone were enrolled in a randomized clinical trial (within-subject comparison). Two implants placed in each were restored using abutments of different geometry. Patients' appreciation was assessed on a visual analog scale (VAS) by recording answers to three questions, and dentists' appreciation was determined by means of the Pink Esthetic Score (PES) at T0 (crown cementation, baseline) and at T12 (1 year post-cementation). ANOVA with post hoc analysis was used to identify differences between groups and at different moments in time. Pearson correlations were calculated between all variables, both at T0 and at T12. RESULTS: No statistically significant differences were found at any time between the control and experimental abutment design, either for the PES or for the VAS score. PES slightly improved after 1 year, as did the VAS rating related to functioning with the implant-crown compared to the natural teeth. All PES and VAS scores demonstrated highly significant correlation. Both patient satisfaction and professional appreciation of muco-gingival conditions after single implant treatment in the esthetic zone were high; however, the curved, experimental abutment design performed no better than the conventional, divergent type. CONCLUSION: Curved abutment design does not significantly impact crown or gingival esthetics as assessed by PES and VAS scored by dentists and patients, respectively.

Papillary fill response in single-tooth implants using abutments of different geometry.

OBJECTIVE: To evaluate the influence of abutment geometry on papillary fill in the esthetic zone in a delayed crown protocol. MATERIALS AND METHODS: Twenty-six subjects received two non-adjacent endosseous implants in the esthetic zone. Functional temporary crowns were installed 17-19 weeks later, using conventional (control) and curved (experimental) abutments. The abutments were randomized in each patient independently. Final crowns were cemented after 2 months (T0). Standard intraoral photographs and radiographs were made to evaluate papillary fill after 12 months (T12). The interproximal papilla fill was measured by means of the papilla index score (PIS) and related to the maximum bone level between the implant and the adjacent root as well as the peri-implant marginal bone level at T12, both measured radiographically. RESULTS: No statistically significant difference between the experimental and the control group could be demonstrated (P = 0.25). Ordinal regression analysis showed a positive correlation between the maximum bone level and papilla fill (P < 0.01) and a negative correlation between the peri-implant marginal bone level and papilla fill (P < 0.05). CONCLUSION: A concave abutment does not exhibit a better fill of the papilla compared with a straight abutment in single-tooth implant placement using a delayed protocol in the esthetic zone after 12 months of function.

Comparison of two different abutment designs on marginal bone loss and soft tissue development.

PURPOSE: To assess the response of soft tissues around two different abutment designs in healed sites in the esthetic zone. MATERIALS AND METHODS: Twenty-six subjects received two endosseous implants in healed, bilateral implant sites in the esthetic zone in the maxilla or the mandible. After 17 to 19 weeks and left/right randomization, the implants were restored with either a conventional (control) or curved (experimental) titanium abutment and a provisional crown. Eight weeks after abutment placement, definitive crowns were cemented (T0). Soft tissue development was assessed based on peri-implant bone loss, Pink Esthetic Score (PES), and probing depths immediately after placement of the definitive crown and after 1 year (T12) and compared between sites. Possible confounding variables (abutment angle, plaque presence, gingival bleeding, width of attached mucosa) were also documented at T0 and T12. RESULTS: The mean peri-implant marginal bone loss from T0 to T12 was 0.00 ± 0.37 mm in the experimental group and 0.12 ± 0.27 mm in the control group. Differences were not statistically significant (P = .25). At T12, the curved abutment scored a mean PES of 10 ± 2.3 and the straight abutment scored 9.7 ± 2.3. The difference was not significant (P = .46)). Probing depths were also not significantly different between the two groups (P = .85). Correlation and regression analysis showed no hints of predictive behavior for the possible confounding variables. CONCLUSION: A titanium abutment with a circumferential curved design is of no additional benefit to soft tissue development and preservation of marginal bone compared to a conventional straight abutment design for the restoration of single-tooth implants in the esthetic zone.

An exploratory study on assessment of gingival biotype and crown dimensions as predictors for implant esthetics comparing caucasian and Indian subjects.

Gingival biotype and crown dimensions may be important predictors for the esthetic outcome of surgical procedures. However, the visual distinction between "thick" and "thin" biotype may not be a suitable predictive parameter of surgical outcome. Intraoral photographs of 73 Indian and Dutch subjects were matched with respect to age and gender and were used to determine the gingival biotype (subjective assessment) and crown dimensions (objective assessment). Intraobserver and interobserver agreement was determined for subjective measurements (Cohen's kappa), and the error of the method was calculated for the objective measurements (Dahlberg formula). Intraobserver agreement for the subjective assessment of gingival biotype was adequate (κ = 0.49-0.60), but interobserver agreement was poor (κ = 0.10), whereas the error of the method for objective assessment of crown dimensions was small. The mean crown width-length angle is smaller in Dutch as compared to Indian subjects in this sample (P < .05). Crown dimensions may be a more quantitative approach and could become a future norm to predict outcomes of implant restorative and surgical procedures, bearing in mind that cross-cultural differences may be present.

A comparative study to evaluate the effect of two different abutment designs on soft tissue healing and stability of mucosal margins.

AIM: To evaluate the effect of two different abutment designs on soft tissue healing and the stability of the mucosal margin in vivo. MATERIALS AND METHODS: Twenty-nine subjects received two, non-adjacent endosseous implants in the esthetic zone. Subsequently, conventional (control) and curved abutments (experimental) were placed in combination with a temporary restoration (left-right randomization). Plaster models of the healed sites were made to assess the stability of the soft tissues at baseline and after 6 weeks. To measure deseating force, a dontrix gauge was used while removing the abutments after 6 weeks. RESULTS: Although visually, differences in the transmucosal area were observed, the differences in marginal recession and in deseating force between abutments from the experimental and the control group never reached a statistically significant level. In general, some gain in soft tissue height was seen in both groups. Angled abutments elicited recession at all buccal sites (P = 0.003-0.02). CONCLUSION: Abutments with a circumferential groove do not lead to a different response of the mucosal margin compared with a regular abutment, and are no more resistant upon removal than regular abutments after 6 weeks of function.