Long-Term Assessment (5- to 19-Year Follow-up) of the Incisal- Level Changes in Single Implants Placed in the Anterior Maxilla: An Observational Clinical Study.

Purpose: To evaluate the occurrence, incidence rate, and esthetic impact of facial growth in adult patients who need a single implant rehabilitation in the central incisor area to assess the influence of time on changes in the incisal level.

Materials and methods: Patients were included if they received a single implant in the maxillary central incisor site, were at least 19 years old at the time of placement, and had natural adjacent teeth. Standardized images were obtained to evaluate the presence and incidence of incisal linear changes. All rehabilitations followed the same standard of reconstruction, while always keeping the mimetics of the homologous and adjacent tooth the same to provide the same incisal level and achieve the best esthetics for all patients. Thus, at implant placement (T0), the incisal-level difference between the crown and the adjacent tooth was zero. Any modifications in the incisal levels from 1.0 mm of difference were registered. This measurement of 1.0 mm was the cutoff mark because it permits easy observation of a difference, either by the dental professional or the patient. The data obtained were analyzed and correlated statistically.

Results: A total of 56 patients and 56 implants were included (age range: 23-63 years; average age: 40.79 ± 12.25 years) in this study. Incisal-level alterations between the tooth and implant were found and had an incidence rate of 19.6%. The study had an average follow-up of 10.7 ± 3.37 years. All implants evaluated had stability and healthy peri-implant tissue conditions throughout the followup period, with a 100% survival rate. There was no statistically significant prevalence of incisal-level changes between males (19%) and females (20%) (P = .238); the incidence rate was 41.7% for patients between 20 and 30 years old, 13.3% for patients between 31 and 40 years old, 23.7% for patients between 41 and 50 years old, and 6.3% in the group over 50 years old; note that there were no statistically significant differences (P = .118) among different age groups. Similarly, no statistically significant difference was observed (P = .262) comparing the number of clinical cases in each subgroup with and without change in the incisal level.

Conclusions: Changes in the incisal level of maxillary anterior crowns retained by single implants in adult patients were present in 19.6% of the cases evaluated. This prevalence was not influenced by sex or age group; however, it was observed more often in dental implant cases with longer follow-ups.