title: Marginal Bone Remodeling around healing Abutment vs Final Abutment Placement at Second Stage Implant Surgery: A 12-month Randomized Clinical Trial.
abstract: BACKGROUND
  The periimplant bone level has been used as one of the criteria to assess the success of dental implants. It has been documented that the bone supporting two-piece implants undergoes resorption first following the second-stage surgery and later on further to abutment connection and delivery of the final prosthesis.
  
  
  OBJECTIVE
  The aim of this multicentric randomized clinical trial was to evaluate the crestal bone resorption around internal connection dental implants using a new surgical protocol that aims to respect the biological distance, relying on the benefit of a friction fit connection abutment (test group) compared with implants receiving conventional healing abutments at second-stage surgery (control group).
  
  
  METHODS
  A total of partially edentulous patients were consecutively treated at two private clinics, with two adjacent two-stage implants. Three months after the first surgery, one of the implants was randomly allocated to the control group and was uncovered using a healing abutment, while the other implant received a standard final abutment and was seated and tightened to 30 Ncm. At each step of the prosthetic try-in, the abutment in the test group was removed and then retightened to 30 Ncm. Horizontal bone changes were assessed using periapical radiographs immediately after implant placement and at 3 (second-stage surgery), 6, 9 and 12 months follow-up examinations.
  
  
  RESULTS
  At 12 months follow-up, no implant failure was reported in both groups. In the control group, the mean periimplant bone resorption was 0.249 ± 0.362 at M3, 0.773 ± 0.413 at M6, 0.904 ± 0.36 at M9 and 1.047 ± 0.395 at M12. The test group revealed a statistically significant lower marginal bone loss of 20.88% at M3 (0.197 ± 0.262), 22.25% at M6 (0.601 ± 0.386), 24.23% at M9 (0.685 ± 0.341) and 19.2% at M9 (0.846 ± 0.454). The results revealed that bone loss increased over time, with the greatest change in bone loss occurring between 3 and 6 months. Alveolar bone loss was significantly greater in the control condition than the test condition.
  
  
  CONCLUSIONS
  The results of this prospective study demonstrated the benefit of placing a prosthetic component with a stable connection at second-stage surgery, in terms of reduced marginal bone remodeling when compared with conventional procedure.
  
  
  CONCLUSIONS
  The use of a stable connection in a healing component during try-in stages prior to final restoration placement leads to less periimplant marginal bone loss.
authors.affiliation: School of Dentistry, Lebanese University, Beirut, Lebanon.
authors.forename: Nabih
authors.initials: N
authors.lastname: Nader
authors.affiliation: School of Dentistry, Lebanese University, Beirut, Lebanon.
authors.forename: Maissa
authors.initials: M
authors.lastname: Aboulhosn
authors.affiliation: Professor, Department of Oral and Maxillofacial Surgery, School of Dentistry, Lebanese University, Beirut, Lebanon, Phone: +9613731173 e-mail: anberberi@gmail.com.
authors.forename: Antoine
authors.initials: A
authors.lastname: Berberi
authors.affiliation: Medical School, Lebanese University, Beirut, Lebanon.
authors.forename: Cordahi
authors.initials: C
authors.lastname: Manal
authors.affiliation: Faculty of Dental Medicine, Saint Joseph University Beirut Lebanon.
authors.forename: Ronald
authors.initials: R
authors.lastname: Younes
mesh_terms: D000368:Aged; D016723:Bone Remodeling; D000044:Dental Abutments; D003758:Dental Implantation, Endosseous; D015921:Dental Implants; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009066:Mouth, Edentulous; D011446:Prospective Studies
chemical_list: D015921:Dental Implants
keywords: Aboulhosn M; Berberi A; Friction fit connection; Healing abutment marginal bone loss; Manal C; Microgap. How to cite this article: Nader N; Younes R. Marginal Bone Remodeling around healing Abutment vs Final Abutment Placement at Second Stage Surgery: A 12-month Randomized Clinical Trial. J Contemp Dent Pract 2016;17(1):7-15. Source of support: Nil Conflict of interest: None.