Periimplant Bone Changes in Different Abutment Heights and Insertion Timing - Three-year Results from a Randomized Prospective Clinical Trial
Author | : Borges Tiago |
Publisher | : |
Total Pages | : |
Release | : 2017 |
ISBN-10 | : OCLC:1163806850 |
ISBN-13 | : |
Rating | : 4/5 (50 Downloads) |
Book excerpt: Background and aimDifferent authors claim that the peri-implant bone remodelling after implant insertion, can be explained by factors like the implant design, the type of abutment connection, the surgical trauma, the establishment of the biological width, number of surgical stages or connection/disconnection of the abutment and prosthetic parts. The biological events that occur in the implant-abutment interface area may explain some of the outcomes related to the periimplant marginal bone. Materials and methodThe study was planned as a prospective, randomized, controlled parallel group including subjects in need of at least two implants for the restoration of an edentulous posterior mandibular area. Data were gathered on age, gender, keratinized mucosa height (KM), bleeding on probing (BoP), smoking habits and previous periodontitis. The patients were allocated into three groups: Group A implants were immediately connected to 2 mm height abutments; Group B implants were immediately connected to 1 mm height abutments; Group C implants were left to heal in a sub-mucosal position and 2 mm abutments were inserted in a second stage surgery. Peri-apical radiographs were taken at the implant surgery (baseline), 4 weeks after surgery (T1), 16 weeks after implant placement at the final restoration delivery (T2), 1-year (T3) and 3 years after implant placement (T4). A multiple linear regression model (stepwise forward) was applied.Statistical significance was set at 0.05. ResultsA total of thirty-two patients, including sixty-eight implants, were enrolled in this study. One implant was lost on group C after the first month of healing. A mean MBL change of 0,35u00b10,46 mm, 0,60u00b10,81 mm and 0,71u00b10,90 mm was computed for groups A, B and C, respectively, at T4. Significant differences were found between group A and C in terms of MBL variation after 3 years of treatment (p=0,048). Multiple linear regression analysis showed a significant influence of the early MBL at T1 has an independent predictor variable for the marginal bone alterations that were assessed at T4 (p