The Effect of Implant Length and Diameter on Stress Distribution of Tooth-Implant and Implant Supported Fixed Prostheses: An In Vitro Finite Element Analysis Study

Abstract

The aim of this study is to evaluate the effectiveness of the implant diameter and length on force dissemination of tooth-implant and implant retained fixed restorations. A finite analysis model was used via a 3D simulation of a unilateral mandibular Kennedy Class I arch. Through thresholding the resultant assembly, a region of interest was selected from the CT scan. Details of the diameter (D) and length (L) of implant were introduced. Ds used were 3.7, 4.7, and 5.7, while Ls used were 10, 11.5, and 13. The constant was the use of rigid connectors in both designs (implant–implant and implant–tooth fixed partial dentures) and the mesial implant (D 3.7 and L 11.5). Stress in cancellous bone around mesial abutment, which is the second premolar in tooth-implant FPD and mesial implant in the implant-implant fixed partial denture (FPD), revealed that the stress was significantly lower in tooth-implant FPD when compared to implant-implant FPD (21.1±0.00 versus 46.1±0.00, p <0.001). Stress distribution in the bone around any implant depends on several factors such as diameter, length, and tooth-implant vs. implant-implant support. The implant diameter was more significant for improved stress distribution than implant length. A moderate increase in the length of the implant consequently reduced stress.

Effect of non‐rigid connector on the stress distribution of tooth‐implant supported fixed prostheses using different implant length and diameter: A comparative 3D finite element study

“…This can be interpreted by the non-rigid connection's function to divide the prosthesis into two different parts; a single crown on the tooth and a cantilever on the implant side resulting in less stress on the tooth itself but increased unfavorable stresses on the prosthesis as well as tooth intrusion. [34][35][36][37][38] In addition the findings complement those of Naguib et al, 18 in regard to stress dissemination, where the diameter of the implant was more pivotal than its length.…”

“…29 This study commenced from previously published work that investigated the significance of implant length and diameter on stress dissemination in tooth-implant fixed dental prosthesis with rigid connection design. Naguib et al, 18 concluded that the increase in implant diameter with a proportionate increase in length was directly related to reduced stress on the prostheses. The main focus of this study was to evaluate different connector designs as an input variable through showing the magnitude of Von Misses stress Contrary to previous research studies supporting non-rigid FDPs that exhibit the least amount of stress and favorable prognosis to the tooth abutment in a tooth-implant FDP, 19,[30][31][32][33] our results demonstrated that FDPs with rigid connection showed considerably lower mean stress values than those with non-rigid connection design.…”

“…This study commenced from previously published work that investigated the significance of implant length and diameter on stress dissemination in tooth‐implant fixed dental prosthesis with rigid connection design. Naguib et al., 18 concluded that the increase in implant diameter with a proportionate increase in length was directly related to reduced stress on the prostheses. The main focus of this study was to evaluate different connector designs as an input variable through showing the magnitude of Von Misses stress calculated at the designs at 6 specific bodies under stationary vertical load (FDP, bone around tooth, bone around distal implant, cementum, PDL, and implant).…”

“…Naguib et al., 18 conducted a recent stress analysis study using 3D finite element analysis for 10 models of FDPs (Implant–implant and tooth–implant FDPs with rigid connectors being inherent for both designs). Implant diameters (D 3.7 mm, 4.7 mm, 5.7 mm) and lengths (L 10 mm, 11.5 mm, 13 mm) were set as input variables and the best combination was investigated.…”

“…Rigid connectors can provide a more diffuse stress distribution, while non-rigid connectors can provide stress-breaking abilities and independent response of abutments to stresses to FDP components and surrounding bone. [14][15][16][17] Naguib et al, 18 conducted a recent stress analysis study using 3D finite element analysis for 10 models of FDPs (Implant-implant and tooth-implant FDPs with rigid connectors being inherent for both designs). Implant diameters (D 3.7 mm, 4.7 mm, 5.7 mm) and lengths (L 10 mm, 11.5 mm, 13 mm) were set as input variables and the best combination was investigated.…”