title: Implant biomechanical stability variation at early implantation times in vivo: an experimental study in dogs.
abstract: OBJECTIVE
  To demonstrate the degree of stability decrease and subsequent increase of dental implants at early implantation times in a beagle model.
  
  
  METHODS
  The mandibular premolars and first molars of eight beagle dogs were extracted and the ridges allowed to heal for 8 weeks. Thirty-two (n = 16 each group) implants were placed bilaterally, and remained in vivo for 1 and 3 weeks. The implants with comparable dimensions were divided as follows: group 1, Straumann Bone Level with SLActive surface; group 2, Nobel Speedy Replace RP with TiUnite surface. During insertion and following sacrifice, the implants were torqued to determine insertion and interface failure values. Histologic sections were prepared for microscopy. Statistical analysis was performed using Kruskal-Wallis and multiple paired and non-paired t tests considering unequal variances at a 95% level of significance.
  
  
  RESULTS
  High insertion torque values were observed along with a significant decrease at 1 week in vivo (P = .003). At 3 weeks, the biomechanical fixation levels increased and were comparable to the insertion torque value. Histology showed that interfacial bone remodeling and initial woven bone formation was observed around both implant groups at 1 and 3 weeks.
  
  
  CONCLUSIONS
  As time elapsed early after implantation, the biomechanical stability of dental implants initially decreased and subsequently increased.
authors.affiliation: Department of Oral and Maxillofacial Surgery, Universidade Federal de Uberlandia, Uberlândia, MG, Brazil.
authors.forename: Julio B
authors.initials: JB
authors.lastname: Gomes
authors.forename: Felipe E
authors.initials: FE
authors.lastname: Campos
authors.forename: Charles
authors.initials: C
authors.lastname: Marin
authors.forename: Hellen S
authors.initials: HS
authors.lastname: Teixeira
authors.forename: Estevam A
authors.initials: EA
authors.lastname: Bonfante
authors.forename: Marcelo
authors.initials: M
authors.lastname: Suzuki
authors.forename: Lukasz
authors.initials: L
authors.lastname: Witek
authors.forename: Darceny
authors.initials: D
authors.lastname: Zanetta-Barbosa
authors.forename: Paulo G
authors.initials: PG
authors.lastname: Coelho
mesh_terms: D000818:Animals; D001641:Bicuspid; D001696:Biomechanical Phenomena; D016723:Bone Remodeling / Q000502:physiology*; D015921:Dental Implants; D003799:Dental Stress Analysis / Q000379:methods*; D004285:Dogs; D008963:Molar; D016348:Osseointegration / Q000502:physiology; D018709:Statistics, Nonparametric; D013997:Time Factors; D019415:Torque
chemical_list: D015921:Dental Implants