Effect of different implant placement depths on crestal bone levels and soft tissue behavior: A 5-year randomized clinical trial.

OBJECTIVES: This randomized clinical trial analyzed the long-term (5-year) crestal bone changes and soft tissue dimensions surrounding implants with an internal tapered connection placed in the anterior mandibular region at different depths (equi- and subcrestal). MATERIALS AND METHODS: Eleven edentulous patients were randomly divided in a split-mouth design: 28 equicrestal implants (G1) and 27 subcrestal (1-3 mm) implants (G2). Five implants were placed per patient. All implants were immediately loaded. Standardized intraoral radiographs were used to evaluate crestal bone (CB) changes. Patients were assessed immediately, 4, 8, and 60 months after implant placement. The correlation between vertical mucosal thickness (VMT) and soft tissue recession was analyzed. Sub-group analysis was also performed to evaluate the correlation between VMT and CB loss. Rank-based ANOVA was used for comparison between groups (α = .05). RESULTS: Fifty-five implants (G1 = 28 and G2 = 27) were assessed. Implant and prosthetic survival rate were 100%. Subcrestal positioning resulted in less CB loss (-0.80 mm) when compared to equicrestal position (-0.99 mm), although the difference was not statistically significant (p > .05). Significant CB loss was found within the G1 and G2 groups at two different measurement times (T4 and T60) (p < .05). Implant placement depths and VMT had no effect on soft tissue recession (p > .05). CONCLUSIONS: There was no statistically significant difference in CB changes between subcrestal and equicrestal implant positioning; however, subcrestal position resulted in higher bone levels. Neither mucosal recession nor vertical mucosa thickness was influenced by different implant placement depths.

Factors Influencing the Presence of Papilla between Adjacent Implants and between a Tooth and an Implant.

AIM: The aim this study was to evaluate the factors that influence the presence or absence of the interproximal papilla between implants adjacent to the teeth or other implants, through clinical and radiographic evaluation. MATERIAL AND METHODS: The non-probabilistic sample comprised 44 patients of both genders aged between 21 and 68 years, rehabilitated with 114 osseointegrated implants. Through a retrospective clinical study, the patients were divided according to the presence or absence of the interproximal papilla: Group 1 - Absence of Papilla, Group 2 - Partial Presence of Papilla and Group 3 - Total Presence of Papilla. The success of the implants, the periodontal biotype, and the vertical and horizontal distances of the interproximal regions included in the study were evaluated. RESULTS: Of the 114 implants, 46.5% were considered unsuccessful, and bleeding was present in 29.8%. The periodontal biotype presented as thin and scalloped was found in 85.1% of the regions. The evaluation of the groups according to the confirmation of the interproximal space showed a statistically significant difference (p = 0.007), with 61.9% of the wide and long interproximal spaces classified as Group 1, while 31% of the narrow and short interproximal spaces were classified as Group 3. CONCLUSION: It was concluded that the morphology of the interproximal space was the factor that was most strongly associated with the presence or absence of the interproximal papilla.

Effect of different implant placement depths on crestal bone levels and soft tissue behavior: a randomized clinical trial.

OBJECTIVES: This randomized clinical trial analyzed crestal bone changes and soft tissue dimensions surrounding implants with an internal tapered connection placed in the mandible anterior region at different depths (equicrestal and subcrestal). MATERIALS AND METHODS: Eleven edentulous patients (five implants per patient) were randomly divided in a split-mouth design: G1, 28 equicrestal implants; and G2, 27 subcrestal implants. All implants were immediately loaded. Correlation between keratinized tissue width (KTW) and vertical mucosa thickness (MT) with soft tissue recession was analyzed. Intraoral radiographs were used to evaluate crestal bone changes. Patients were assessed immediately, 4-, and 8-months after implant placement. Rank-based ANOVA-type statistical test was used for comparison between groups (α = 0.05). RESULTS: Fifty-five implants (G1 = 28 and G2 = 27) were assessed in 11 patients. Implant survival rate was 100% for both groups. Both tested implant placement depths presented similar crestal bone loss (P > 0.05). Significant crestal bone loss for each group was found in the different measurement times (T4 and T8) (P < 0.05). Implant placement depths, KTW, and vertical MT had no effect on soft tissue recession (P > 0.05). CONCLUSIONS: Different implant placement depths do not influence crestal bone changes. Soft tissue behavior is not influenced by different implant placement depths or by the amount of keratinized tissue.