title: The influence of soft tissue thickness on crestal bone changes around implants: a 1-year prospective controlled clinical trial.
abstract: OBJECTIVE
  The aim of this clinical trial was to evaluate the influence of gingival tissue thickness on crestal bone loss around dental implants after a 1-year follow-up.
  
  
  METHODS
  Forty-six implants (23 test and 23 control) were placed in 19 patients. The test implants were placed about 2 mm supracrestally, whereas the control implants were positioned at the bone level. Before implant placement, the tissue thickness at implant sites was measured with a periodontal probe. After healing, metal-ceramic cement-retained prostheses were constructed. According to tissue thickness, the test implants were divided into A (thin) and B (thick) groups. Intraoral radiographs were performed and crestal bone changes were measured at implant placement and after 1 year.
  
  
  RESULTS
  Mean bone loss around the test implants in group A (thin mucosa) was 1.61 +/- 0.24 mm (SE; range, 0.9 to 3.3 mm) on the mesial and 1.28 +/- 0.167 mm (range, 0.8 to 2.1 mm) on the distal. Mean bone loss in test group B (thick mucosa) implants was 0.26 +/- 0.08 mm (range, 0.2 to 0.9 mm) on the mesial aspect and 0.09 +/- 0.05 mm (range, 0.2 to 0.6 mm) on the distal aspect. Mean bone loss around control implants was 1.8 +/- 0.164 mm (range, 0.6 to 4.0 mm) and 1.87 +/- 0.166 mm (range, 0.0 to 4.1 mm) on the mesial and distal aspects, respectively. Analysis of variance revealed a significant difference in terms of bone loss between test A (thin) and B (thick) groups on both the mesial and the distal.
  
  
  CONCLUSIONS
  Initial gingival tissue thickness at the crest may be considered as a significant influence on marginal bone stability around implants. If the tissue thickness is 2.0 mm or less, crestal bone loss up to 1.45 mm may occur, despite a supracrestal position of the implant-abutment interface.
authors.affiliation: Institute of Odontology, Faculty of Medicine, Vilnius University, Lithuania. linktomo@gmail.com
authors.forename: Tomas
authors.initials: T
authors.lastname: Linkevicius
authors.forename: Peteris
authors.initials: P
authors.lastname: Apse
authors.forename: Simonas
authors.initials: S
authors.lastname: Grybauskas
authors.forename: Algirdas
authors.initials: A
authors.lastname: Puisys
mesh_terms: D000328:Adult; D000368:Aged; D016301:Alveolar Bone Loss / Q000000981:diagnostic imaging / Q000209:etiology; D000539:Alveolar Process / Q000000981:diagnostic imaging / Q000473:pathology*; D015519:Bone Density / Q000502:physiology; D003442:Crowns; D000044:Dental Abutments; D003738:Dental Cements / Q000737:chemistry; D003758:Dental Implantation, Endosseous / Q000379:methods; D015921:Dental Implants; D019094:Dental Prosthesis, Implant-Supported; D003830:Denture, Partial, Fixed; D005260:Female; D005500:Follow-Up Studies; D005881:Gingiva / Q000473:pathology*; D006801:Humans; D007576:Jaw, Edentulous, Partially / Q000534:rehabilitation / Q000601:surgery; D008297:Male; D008334:Mandible / Q000601:surgery; D008437:Maxilla / Q000601:surgery; D016876:Metal Ceramic Alloys / Q000737:chemistry; D008875:Middle Aged; D016348:Osseointegration / Q000502:physiology; D010517:Periodontics / Q000295:instrumentation; D011446:Prospective Studies; D011859:Radiography; D014945:Wound Healing; D055815:Young Adult
chemical_list: D003738:Dental Cements; D015921:Dental Implants; D016876:Metal Ceramic Alloys