title: Prospective evaluation of immediate and delayed provisional single tooth restorations.
abstract: OBJECTIVE
  The purpose of this study was 2-fold: to determine whether there is a significant difference in the hard and soft tissue response comparing immediate with delayed implant placement after tooth removal, with immediate provisionalization, in maxillary anterior sites; and to determine and compare the crestal bone levels as the primary endpoint variable for implants placed and immediately temporized in extraction sites, to implants placed into extraction sites after the extraction site has been grafted and healed for 4 months, all immediately restored with an anatomic provisional restoration. This aim was to be evaluated by measuring crestal bone levels on standardized digital radiographs of the implants, using implant threads as a monitor of magnification and a pre-extraction reference. Secondary endpoint variables include soft tissue measures compared with method.
  
  
  METHODS
  A total of 76 patients were recruited and randomized into treatment groups. Group 1 had a maxillary tooth (premolar, canine, lateral or central incisor) removed, with immediate socket grafting, followed by implant placement and provisionalization 4 months later with a single tooth. Group 2 had immediate implant placement and provisionalization. Standardized radiograph holders were used to expose digital radiographs every 6 months from baseline to up to 2 years restored. Soft tissue measures were made from standardized reference points. Data collected were analyzed by a statistician to test the hypotheses.
  
  
  RESULTS
  A total of 55 patients completed their follow-up. Twenty-one patients were lost to follow-up because of implant loss (n = 5), 1 treated out of protocol because of labial bone loss found at the time of tooth removal (n = 1), geographic relocation (n = 11), dropped for noncompliance (n = 3), or medical problems (n = 1). The analyses showed no significant differences between groups in implant integration or crestal interdental bone movement on either the implant or the adjacent tooth. The bone level on the implants did move from the baseline levels during the first 6 months but not thereafter. There were no differences (P > .05) observed when comparing the interactions between groups, tooth locations, or time. There was a significant (P < .05) difference in the position of the facial gingival margin with a more apical position of the facial gingival margin in the delayed group compared with the immediate group during the course of the study.
  
  
  CONCLUSIONS
  Crestal bone response to immediate or delayed placement of an implant into an extraction site in the maxillary anterior region with immediate provisionalization is similar regarding hard tissue changes. Support of the gingival margin with a provisional at the time of tooth extraction and implant placement preserved 1 mm more facial gingival margin position compared with the delayed group. The decision to use either method must consider the movement of the facial gingival margin, which, in a critical esthetic patient may require soft tissue support from a provisional restoration or similar type of anatomical healing abutment.
authors.affiliation: Department of Oral and Maxillofacial Surgery, LSU School of Dentistry, Louisiana State University, New Orleans, LA, USA. drblock@cdrnola.com
authors.forename: Michael S
authors.initials: MS
authors.lastname: Block
authors.forename: Donald E
authors.initials: DE
authors.lastname: Mercante
authors.forename: Denise
authors.initials: D
authors.lastname: Lirette
authors.forename: Waheed
authors.initials: W
authors.lastname: Mohamed
authors.forename: Mark
authors.initials: M
authors.lastname: Ryser
authors.forename: Paulino
authors.initials: P
authors.lastname: Castellon
mesh_terms: D000328:Adult; D000368:Aged; D016301:Alveolar Bone Loss / Q000000981:diagnostic imaging / Q000209:etiology / Q000517:prevention & control*; D016025:Bone Transplantation; D003442:Crowns; D003758:Dental Implantation, Endosseous / Q000009:adverse effects / Q000379:methods*; D019250:Dental Implants, Single-Tooth / Q000009:adverse effects; D019094:Dental Prosthesis, Implant-Supported; D019232:Dental Restoration Failure; D003794:Dental Restoration, Temporary; D005260:Female; D005889:Gingival Recession / Q000209:etiology / Q000517:prevention & control*; D006801:Humans; D016014:Linear Models; D008297:Male; D008437:Maxilla / Q000601:surgery; D008875:Middle Aged; D011446:Prospective Studies; D011859:Radiography; D016037:Single-Blind Method; D013997:Time Factors; D014081:Tooth Extraction / Q000009:adverse effects; D020390:Tooth Socket / Q000601:surgery*; D055815:Young Adult