Journal of Oral Implantology December 2013 - (Page 697)

RESEARCH Influence of Fine Threads and Platform-Switching on Crestal Bone Stress Around Implant-A ThreeDimensional Finite Element Analysis Pardeep Khurana, MDS1* Arun Sharma, MS2 Kiranmeet Kaur Sodhi, MDS3 The aims of this study were to investigate the effect of implant fine threads on crestal bone stress compared to a standard smooth implant collar and to analyze how different abutment diameters influenced the crestal bone stress level. Three-dimensional finite element imaging was used to create a cross-sectional model in SolidWorks 2007 software of an implant (5-mm platform and 10 mm in length) placed in the premolar region of the mandible. The implant model was created to resemble a commercially available fine thread implant. Abutments of different diameters (5.0 mm: standard, 4.5 mm, 4.0 mm, and 3.5 mm) were loaded with a force of 100 N at 908 vertical and 408 oblique angles. Finite element analysis was done in COSMOSWorks software, which was used to analyze the stress patterns in bone, especially in the crestal region. Upon loading, the fine thread implant model had greater stress at the crestal bone adjacent to the implant than the smooth neck implant in both vertical and oblique loading. When the abutment diameter decreased progressively from 5.0 mm to 4.5 mm to 4 mm and to 3.5 mm the thread model showed a reduction of stress at the crestal bone level from 23.2 MPa to 15.02 MPa for fine thread and from 22.7 to 13.5 MPa for smooth collar implant group after vertical loading and from 43.7 MPa to 33.1 MPa in fine thread model and from 36.9 to 20.5 MPa in smooth collar implant model after oblique loading. Fine threads increase crestal stress upon loading. )Reduced abutment diameter that is platform switching resulted in less stress translated to the crestal bone in the fine thread and smooth neck. Key Words: implant fine thread, crestal bone stress, platform switching, finite element analysis INTRODUCTION T he success of dental implants is highly dependent upon the integration between the implant and the intra-oral hard/soft tissue. The initial breakdown of the implant-tissue interface generally begins at the crestal region in successfully osseointegrated endosteal implants regardless of surgical 1 Department of Conservative Dentistry & Endodontics, Swami Devi Dyal Dental College & Hospital, Panchkula, India. 2 Department of Mechanical Engineering, Michigan Technological University, Houghton, Mich. 3 Department of Prosthodontics, Swami Devi Dyal Dental College & Hospital, Panchkula, India. * Corresponding author, e-mail: drpkhurana@yahoo.com DOI: 10.1563/AAID-JOI-D-10-00148 approaches, with the potential to cause implant failure. The implant body has macroscopic design-like threads whereas the crest module is often smoother to impair plaque retention if crestal bone loss occurs. Clinical success and longevity of endosteal dental implants are controlled in large by the health of the surrounding crestal region of bone and soft tissue. Early implant failure is also the consequence of too much stress applied to the implant system.1 The first report quantifying early crestal bone loss was a 15-year retrospective study by Adell2 who reported 1.2-mm marginal bone loss from the first thread during healing and in the first year after loading with average of 0.005 mm to 0.13 mm bone Journal of Oral Implantology 697

Table of Contents for the Digital Edition of Journal of Oral Implantology December 2013

Blade-Form Dental Implants: FDA Reclassification as a Class II Dental Implant Device
Effect of Different Storage Media on the Regenerative Potential of Autogenous Bone Grafts: A Histomorphometrical Analysis in Rabbits
Tensile Resistance of Mineralized and Demineralized Rat Bones in Different Regions (Calvarial and Femur)
Microbial Diversity of Peri-Implant Biofilms on Implant Fixed Bar and Telescopic Double Crown Attachments
Evidence-Based Techniques to Assess the Performance of Dental Implants
Influence of Platform and Abutment Angulation on Peri-Implant Bone. A Three- Dimensional Finite Element Stress Analysis
Direct Current Electric Stimulation in Implant Osseointegration: An Experimental Animal Study With Sheep
Prevalence of Sinus Augmentation Associated With Maxillary Posterior Implants
The Bactericidal Effects of an Acidified Sodium Chlorite-Containing Oral Moisturizing Gel: A Pilot Study
Influence of Fine Threads and Platform-Switching on Crestal Bone Stress Around Implant— A Three-Dimensional Finite Element Analysis
An Evaluation of the Resonance Frequency Analysis Device: Examiner Reliability and Repeatability of Readings
Histologic and Histomorphometric Assessment of Implants and Periapical Tissues When Placed in the Sockets of Extracted Teeth, Teeth With Periapical Lesions, and Healed Lesions: A Canine Study
Microbiological Aspects of Human Mandibular Subperiosteal Dental Implants
A Technique for Removal of a Fractured Implant Abutment Screw
Eight-Year Results of Site Retention of Anorganic Bovine Bone and Anorganic Bovine Matrix
A Reactive Lesion (Pyogenic Granuloma) Associated With Dental Implant: A Case Report
Twelve-Year Clinical and Radiological Results of Maxillary and Mandibular Implant- Retained Bar Overdentures Carried out on Oxidized (TiUnite) Replace Select Implants: A Clinical Case
PEEK Dental Implants: A Review of the Literature

Journal of Oral Implantology December 2013