Student Theses, Dissertations and Capstones

Document Type


Degree Name

Master of Science (M.S.) in Dentistry

Copyright Statement

All rights reserved. This publication is intended for use solely by faculty, students, and staff of Nova Southeastern University. No part of this publication may be reproduced, distributed, or transmitted in any form or by any means, now known or later developed, including but not limited to photocopying, recording, or other electronic or mechanical methods, without the prior written permission of the author or the publisher.


College of Dental Medicine

First Advisor

Theofilos Koutouzis

Publication Date / Copyright Date



Nova Southeastern University


Introduction: For optimal dental implant esthetics the transition of a circumferential implant platform to a proper cervical anatomy has been emphasized. This transition is facilitated by the macro-design of the transmucosal portion of the abutment-restoration complex at the provisional and final stages of implant prosthetic therapy. There is limited information from human studies assessing the impact of abutment macro-design on periimplant tissue dimensional changes. Therefore, the aim of this study was to evaluate prospectively the effect of abutment macro-design on peri-implant tissue dimensional changes. Methods: This is an ongoing randomized control clinical trial in which twentyeight (28) patients with a missing maxillary premolar, have been treated with single implant supported crowns. Implant placement and abutment design were planned with a software for guided implant treatment. Implants were placed 1 mm subcrestally with the aid of a surgical guide, and permanent CAD-CAM fabricated abutments with different configurations of the emergence shape were connected to the implants and temporary vii crowns delivered. Patients of the convex group had abutments with convex emergence shape and patients of the concave group had permanent abutments with concave emergence shape. All implants were restored at 3 months following implant placement and followed for 12 and 36 months. Clinical and radiographic data was collected at the time of the surgery, at 2 ,3,12, and 36 months. This is a report at the completion of the restorative phase of the treatment (3 months). The primary outcome variable was change of buccal peri-implant margin position. Results: One patient from the convex group (n=13) dropped out of the study and in one patient from the concave group (n=13) the implant failed to integrate. The change on the buccal peri-implant mucosa margin from the time of implant placement to 3 months was -0.76  0.59 mm for the convex group and -0.50 1.0 mm for the concave group (p>0.05). 68% of implants in the convex group and 76% of implants in the concave group had 1mm buccal mucosal recession. Radiographically change on subcrestal implant position was -0.41  0.36 mm for the convex group and -0.24  0.26 mm for the concave group (p>0.05). Direct logistic regression analysis showed that reduced buccal plate thickness influenced the likelihood for 1mm recession with an odds ratio of 0.20. Conclusions: The study failed to support the hypothesis that abutment macrodesign can influence early (3 month) peri-implant mucosa changes. Buccal plate thickness was associated with the amount of buccal mucosal recession.




Abutment macrodesign, Implant, One abutment one time



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