title: Consecutive unsplinted implant-supported restorations to replace lost multiple adjacent posterior teeth: A 4-year prospective cohort study.
abstract: OBJECTIVE
  The aim of this study was to investigate the various events occurring in unsplinted implant restoration in posterior jaws during a period of 4 years.
  
  
  METHODS
  From August 2008 to April 2009, eight volunteers (three men and five women) who had two or more consecutively missing teeth received 20 implants in posterior maxillae and mandibles. Unsplinted single crowns were delivered to each implant. For the 4-year follow-up periods, patients were enrolled in a maintenance schedule at 1, 3, 6, 12, 24, 36 and 48 months. The data, including a questionnaire, radiography, mobility and probing were recorded on regular check-ups.
  
  
  RESULTS
  A total of 20 implants in eight patients were followed up for 48 months, showing a 100% survival rate. Mean marginal bone loss around implants was 0.26 mm. Statistical analysis revealed insignificant correlation between metal-ceramic and zirconia-ceramic crowns and among implant lengths (8.5 mm, 10 mm and 11.5 mm). Mean probing depths were similar or insignificantly different, regardless of the materials used or length of implants. The most frequent complications, in decreasing order, were food impaction (65%) and porcelain chipping (45%), sensitivity (25%), pain (20%) and loose contact (15%). Compared with metal-ceramic crowns, zirconia-ceramic crowns showed more unfavorable cases of porcelain chipping (p=0.017), pain (p=0.007) and loose contact with an adjacent crown (p=0.031).
  
  
  CONCLUSIONS
  Within the limits of the sample size, this study showed that unsplinted implant-supported single restorations to replace consecutive posterior missing teeth may function well.
authors.affiliation: Department of Periodontology, Section of Dentistry, Seoul National University Bundang Hospital , Seongnam , Korea.
authors.forename: Jung-Tae
authors.initials: JT
authors.lastname: Lee
authors.forename: Hyo-Jung
authors.initials: HJ
authors.lastname: Lee
authors.forename: Shin-Young
authors.initials: SY
authors.lastname: Park
authors.forename: Hae-Young
authors.initials: HY
authors.lastname: Kim
authors.forename: In-Sung
authors.initials: IS
authors.lastname: Yeo
mesh_terms: D000328:Adult; D016301:Alveolar Bone Loss / Q000145:classification; D002516:Ceramics / Q000737:chemistry; D015331:Cohort Studies; D003442:Crowns; D015921:Dental Implants; D003764:Dental Materials / Q000737:chemistry; D003776:Dental Porcelain / Q000737:chemistry; D017267:Dental Prosthesis Design; D019094:Dental Prosthesis, Implant-Supported; D019232:Dental Restoration Failure; D005260:Female; D005500:Follow-Up Studies; D005502:Food; D006801:Humans; D007576:Jaw, Edentulous, Partially / Q000534:rehabilitation; D008297:Male; D016876:Metal Ceramic Alloys / Q000737:chemistry; D008875:Middle Aged; D010514:Periodontal Pocket / Q000145:classification; D011446:Prospective Studies; D016019:Survival Analysis; D016388:Tooth Loss / Q000534:rehabilitation*; D016896:Treatment Outcome; D015040:Zirconium / Q000737:chemistry
chemical_list: D015921:Dental Implants; D003764:Dental Materials; D016876:Metal Ceramic Alloys; D003776:Dental Porcelain; D015040:Zirconium; C028541:zirconium oxide
keywords: dental prosthesis design; prospective studies; single-tooth dental implants