Radiographic evaluation of marginal bone levels around platform-switched and non-platform-switched implants used in an immediate loading protocol.

PURPOSE The aim of this clinical study was to assess the marginal bone around two different types of implant-abutment junctions-a so-called platform-switched assembly and a conventional external-hexagon connection-after 24 months. MATERIALS AND METHODS Forty-five patients were included in this prospective study. All selected patients required the extraction of one or two hopeless teeth in maxillary and mandibular region monoradicular and second premolar teeth, and were randomly assigned to one of two groups. The first group received 34 implants with an external-hexagon junction with the abutment and the second group received 30 implants with platform-switched abutments. Implants were positioned immediately after tooth extraction and were loaded immediately. RESULTS After 24 months, a cumulative survival rate of 100% was reported for all implants. The platform-switching group showed a mean bone loss of 0.78 +/- 0.49 mm and the external-hexagon group showed a mean bone loss of 0.73 +/- 0.52 mm (no statistically significant difference between groups). CONCLUSION The results of this study indicate that implants placed immediately in fresh extraction sockets and loaded immediately represent a predictable procedure, with no differences in bone level changes between "platform-switched" and conventional external-hexagon implants after 24 months.

[1]  J. Wennström,et al.  Modeling of the buccal and lingual bone walls of fresh extraction sites following implant installation. , 2006, Clinical oral implants research.

[2]  G. Romanos,et al.  Immediate loading with complete implant-supported restorations in an edentulous heavy smoker: histologic and histomorphometric analyses. , 2005, The International journal of oral & maxillofacial implants.

[3]  D. van Steenberghe,et al.  The use of e-PTFE barrier membranes for bone promotion around titanium implants placed into extraction sockets: a prospective multicenter study. , 1994, The International journal of oral & maxillofacial implants.

[4]  H. F. Morris,et al.  AICRG, Part II: Crestal bone loss associated with the Ankylos implant: loading to 36 months. , 2004, The Journal of oral implantology.

[5]  Iole Vozza,et al.  Immediate restoration of single implants placed immediately after tooth extraction. , 2006, Journal of periodontology.

[6]  Kitichai Rungcharassaeng,et al.  Immediate placement and provisionalization of maxillary anterior single implants: 1-year prospective study. , 2003, The International journal of oral & maxillofacial implants.

[7]  M. Norton,et al.  Marginal bone levels at single tooth implants with a conical fixture design. The influence of surface macro- and microstructure. , 1998, Clinical oral implants research.

[8]  Antonio Barone,et al.  Bucco-lingual bone remodeling around implants placed into immediate extraction sockets: a case series. , 2003, Journal of periodontology.

[9]  M. Klingensmith,et al.  Patient Selection and Preparation , 2004 .

[10]  A. Piattelli,et al.  Immediately loaded titanium implant with a tissue-stabilizing/maintaining design ('beyond platform switch') retrieved from man after 4 weeks: a histological and histomorphometrical evaluation. A case report. , 2008, Clinical oral implants research.

[11]  Ugo Covani,et al.  Immediate restoration of implants placed into fresh extraction sockets for single-tooth replacement: a prospective clinical study. , 2005, The International journal of periodontics & restorative dentistry.

[12]  Marcus Abboud,et al.  Immediate loading of single-tooth implants in the posterior region. , 2005, The International journal of oral & maxillofacial implants.

[13]  D Buser,et al.  Influence of the size of the microgap on crestal bone changes around titanium implants. A histometric evaluation of unloaded non-submerged implants in the canine mandible. , 2001, Journal of periodontology.

[14]  T G Wilson,et al.  Implants placed in immediate extraction sites: a report of histologic and histometric analyses of human biopsies. , 1998, The International journal of oral & maxillofacial implants.

[15]  U. Lekholm,et al.  Patient selection and preparation , 1985 .

[16]  J. Wennström,et al.  Tissue modeling following implant placement in fresh extraction sockets. , 2006, Clinical oral implants research.

[17]  R. Haas,et al.  Radiologic follow-up of peri-implant bone loss around machine-surfaced and rough-surfaced interforaminal implants in the mandible functionally loaded for 3 to 7 years. , 2004, The International journal of oral & maxillofacial implants.

[18]  A. Wenzel,et al.  Bone healing and soft tissue contour changes following single-tooth extraction: a clinical and radiographic 12-month prospective study. , 2003, The International journal of periodontics & restorative dentistry.

[19]  G. Rasperini,et al.  Preservation of peri-implant soft and hard tissues using platform switching of implants placed in immediate extraction sockets: a proof-of-concept study with 12- to 36-month follow-up. , 2007, The International journal of oral & maxillofacial implants.

[20]  A. Piattelli,et al.  Immediate Placement and Loading of Dental Implants: A Human Histologic Case Report , 2008 .

[21]  S. Hansson,et al.  The implant neck: smooth or provided with retention elements. A biomechanical approach. , 1999, Clinical oral implants research.

[22]  W Becker,et al.  Guided tissue regeneration for implants placed into extraction sockets: a study in dogs. , 1991, Journal of periodontology.

[23]  N. Lang,et al.  Clinical parameters for the evaluation of dental implants. , 1994, Periodontology 2000.

[24]  Enrico Gherlone,et al.  Immediate occlusal loading of implants placed in fresh sockets after tooth extraction. , 2007, The International journal of oral & maxillofacial implants.

[25]  L. Rimondini,et al.  Tissue healing in implants immediately placed into postextraction sockets: a pilot study in a mini-pig model. , 2005, Oral surgery, oral medicine, oral pathology, oral radiology, and endodontics.

[26]  A. Piattelli,et al.  Role of the microgap between implant and abutment: a retrospective histologic evaluation in monkeys. , 2003, Journal of periodontology.

[27]  E. Keller,et al.  Endosseous implant placement immediately following dental extraction and alveoloplasty: preliminary report with 6-year follow-up. , 1992, The International journal of oral & maxillofacial implants.