Cambios volumétricos y perfilométricos en la restauración de premolares maxilares desvitalizados mediante método convencional versus implantarioestudio clínico aleatorio controlado

Abstract

Methods: A randomized controlled clinical trial was conducted at the University of Geneva, where 20 patients were recruited and total of 21 premolars were treated. After random allocation, either conventional retreatment option (CTG-control) or implant treatment (ITGtest) based on contour augmentation around early-placed implants (Type 2 placement) using autogenous bone chips combined with deproteinized bovine bone mineral (DBBM) and a collagen barrier membrane was performed. Clinical and esthetic parameters were recorded to assess treatment outcomes. In particular, quantitative measurements based on 3D laser scanning were used. Results: All 21 retreated premolars (n=9) or implants (n=12) were clinically successful according to strict success criteria. The implants demonstrated ankylotic stability without signs of a peri-implant infection. The linear measurements showed that, in the area where the augmentation was performed, the mean distance between the preoperative vestibular profile and the postoperative one ranged from -0,7 to -1,1 mm in ITG, while in the control group ranged from 0.1 to -0,05 mm. Also, the gingival margin suffered an apical displacement from baseline to the postoperative position in ITG (mean=-0,7mm) while control group remains practically unchanged (mean=0,02 mm). These differences were statistically significant. On the other hand, when evaluating the 2-year follow up stability of the gingival profile and gingival margin position minimal changes were found and with no statistical difference between groups. Conclusion: Treatment of a compromised and devitalized maxillary premolar, which objectively need retreatment is a predictable therapeutic procedure and with little number of complications during treatment, either through conventional endodontic retreatmentprosthetic or by replacing it with an osseointegrated implant using an early implant placement protocol. Retreatment of devitalized maxillary premolars by conventional techniques will not result in changes at the level of the alveolar ridge profile and the changes at the gingival margin will be clinically negligible. Replacement of a maxillary premolar by an early implant placement following a combined protocol with GBR will not faithfully reproduce the pre-extraction alveolar original profile. Consequently, the gingival margin position suffer apical and lingual displacement which differs from the original tridimensional margin position. The position of the gingival margin and alveolar profile obtained after the regenerative therapy remained extremely stable from the placement of the final crown up to two- year of follow up.