A 3-D Finite Element Analytical Study to Evaluate the Effects of Newer Variable
Implant Thread Pattern in Different Bone Densities
Dr. Abhijeet Ramchandra Kore,
E-405, Suncity Apartment, Behind Old Rajtara Hotel, Malakapur, Karad-415110, Maharashtra.
Introduction: Success of dental implant treatment depends on number of patient related and procedure dependent parameters. Various studies have shown that bone quality and implant design are two important factors in the success of dental implant treatment. Today, many implant systems are coming up with variable thread patterns. There is not much literature available on the effects of such variable thread patterns within different bone densities.
Aim: The study was conducted to evaluate the effect of two different implant thread patterns in two different bone densities using three dimensional finite element analyses.
Materials and Methods: A three-dimensional finite element model of a mandibular section of bone and an implant was developed. 4.2x12 mm screw type dental implants with two different thread designs (buttress thread design and variable thread design) and a metal ceramic crown using Co-Cr and feldspathic porcelain were modelled. The model was developed with finite element software and two types of bone qualities were prepared (D2 and D4). A load of 450 N was applied in a vertical direction and in an oblique direction to the central fossa, buccal cusp and distal fossa of the mandibular first molar crown.
Results: For the variable thread design, von Mises stresses developed within bone were 109.89 MPa and 257.46 MPa for vertical and oblique loading respectively, in D2 type of bone. While in D4, the stresses were 243.91 MPa and 371.81 MPa for vertical and oblique loading respectively. Similarly, for buttress thread design, stresses were 113.51 MPa and 176.14 MPa for vertical and oblique loading respectively in D2 type of bone; while in D4 type of bone the stresses were 290.99 MPa and 481.27 MPa respectively within the bone.
Conclusion: The results of the present study showed that the von Mises stresses were more in D4 type of bone as compared to D2 type of bone for both, the variable and buttress thread designs. The study also compared the two thread designs. Less stresses were seen with the variable thread pattern than in the buttress thread pattern particularly in D4 type of bone.