title: Comparison of Crestal Bone Loss along Two Implant Crest Module Designs.
abstract: BACKGROUND
  Crestal bone loss along the dental implant surface deranges its prognosis and is known to occur with implants having 02 mm smooth crest module/collar design. Implants with rough coated crest module/collar design are said to reduce crestal bone loss. Comparison of crestal bone loss with both crest module/collar designs of implants needs to be done.
  
  
  METHODS
  Twenty cases were selected. Each case received one implant with smooth collar design (Group-A) and one implant with coated rough collar design (Group-B). All the 40 implants were prosthetically loaded after a healing period of six months. Crestal bone loss was measured on mesial, distal, buccal and lingual side of each implant using maxillofacial computed tomography at six, twelve and eighteen months time interval after placing the implants. Soft tissue evaluation was carried out around each implant using Gingival, Plaque and Calculus Indices, six and twelve months after loading the implants.
  
  
  RESULTS
  After 18 months i.e. one year after loading the implants, Group-A implants showed an overall average crestal bone loss of 1.53 mm and Group-B implants showed average bone loss of 1.42 mm, the difference being statistically significant (p < 0.05). For both types of implants, average crestal bone loss was maximum on the buccal side, followed by mesial, lingual and distal sides. Soft tissue evaluation revealed that the tissues remained healthy till the end of study for both types of implants.
  
  
  CONCLUSIONS
  Crestal bone loss was less among implants with rough collar design as compared to smooth collar design.
authors.affiliation: Graded Specialist (Prosthodontics), MDC, Meerut.
authors.forename: M M
authors.initials: MM
authors.lastname: Goswami
keywords: Crest module design; Crestal bone loss; Implant