Inverted body-shift concept in macroimplant design to enhance biologic and esthetic outcomes: A clinical report

Anterior implant restorations with a convex emergence profile increase the frequency of recession: 12-month results of a randomized controlled clinical trial

AIM

To test whether the emergence profile (CONVEX or CONCAVE) of implant-supported crowns influences the mucosal margin stability up to 12 months after insertion of the final restoration.

MATERIALS AND METHODS

Forty-seven patients with a single implant in the anterior region were randomly allocated to one of three groups: (1) CONVEX (n = 15), implant provisional and an implant-supported crown both with a convex profile; (2) CONCAVE (n = 16), implant provisional and an implant-supported crown both with a concave profile; (3) CONTROL (n = 16), no provisional (healing abutment only) and an implant-supported crown. All patients were recalled at baseline, 6, and 12 months. The stability of mucosal margin along with clinical, aesthetic, and profilometric outcomes as well as time and costs were evaluated. To predict the presence of recession, multivariable logistic regressions were performed and linear models using generalized estimation equations were conducted for the different outcomes.

RESULTS

Forty-four patients were available at 12 months post-loading. The frequency of mucosal recession amounted to 64.3% in group CONVEX, 14.3% in group CONCAVE, and 31.4% in group CONTROL. Regression models revealed that a CONVEX profile was significantly associated with the presence of recessions (odds ratio: 12.6, 95% confidence interval: 1.82-88.48, p = .01) compared with the CONCAVE profile. Pink aesthetic scores amounted to 5.9 in group CONVEX, 6.2 in group CONCAVE, and 5.4 in group CONTROL, with no significant differences between the groups (p = .735). Groups CONVEX and CONCAVE increased the appointments and costs compared with the CONTROL group.

CONCLUSIONS

The use of implant-supported provisionals with a CONCAVE emergence profile results in a greater stability of the mucosal margin compared with a CONVEX profile up to 12 months of loading. This is accompanied, however, by increased time and costs compared with the absence of a provisional and may not necessarily enhance the aesthetic outcomes.

TRIAL REGISTRATION

German Clinical Trials Register; DRKS00009420.

The effect of implant macrogeometry in immediate tooth replacement therapy: A case series

The concept of immediate tooth replacement therapy (ITRT) in the esthetic zone has become a viable treatment modality and widely accepted in clinical practice. However, achieving adequate primary stability that enables immediate provisional restoration and desirable space for bone-grafting with conventional tapered body implant designs is challenging. The macro-hybrid implant design with a prosthetic angle correction and body-shift feature in a singular form provides not only greater primary stability of a wider diameter implant but also circumferential gap distance both facially and interproximally preserve the labial bone plate and interdental attachment apparatus of the adjacent natural teeth thereby maintaining the interdental papilla. The present clinical series exemplifies the clinical advantages of this inverted body-shift implant design in ITRT in various clinical scenarios in (1) single tooth replacement in a Type 1 intact socket with a thin periodontal phenotype, (2) single tooth replacement in a Type 2 socket with a dentoalveolar dehiscence of the labial bone plate, and (3) multiple adjacent teeth replacement of two maxillary central incisor. CLINICAL SIGNIFICANCE: The macro-hybrid design implant with a prosthetic angle correction and body-shift feature in a singular form provides greater midfacial gap distance as well as tooth-to-implant distance to preserve the interdental attachment of the adjacent natural teeth thereby leaving the interdental papilla undisturbed, without sacrificing higher primary stability afforded by larger diameter implants.