Fatigue resistance and fracture strength of narrow‐diameter one‐piece zirconia implants with angled abutments

Abstract

Objective: Zirconia implants are assumed to satisfy the esthetic requirements that titanium implants cannot meet, however, there are not enough studies in the literature about narrow-diameter and angled zirconia implants that can be preferred especially in the anterior region. This in vitro study aimed to evaluate the fatigue resistance and fracture strength of narrow-diameter zirconia implants with angled abutments. Materials and Methods: Forty-eight one-piece experimental zirconia implants and monolithic zirconia crowns were produced from 3-YTZP blanks. The implant diameters (3.0 or 3.7 mm) and the restoration types were determined according to three intraoral regions (upper central incisors, lower central incisors, and upper canine), and abutments were designed as straight or 15 angled. The samples were subjected to chewing simulation corresponding to 5 years of clinical performance and then the static loading test. The survival rates of groups were measured by the Kaplan-Meier log-rank test, and the fracture load values were estimated by using Kruskal-Wallis and Mann-Whitney U tests (p < 0.05).Results: All 3.0 mm diameter implants failed the fatigue test. The fatigue resistance of the implants with angled abutments was significantly lower than the straight abutments, and different crown designs were found to affect survival rates significantly. The fracture strengths of the surviving groups were above the maximum physiological chewing forces, and the differences were not significant. Conclusions:The implant diameter, abutment angle, and restoration type have a significant effect on the fatigue behavior of zirconia implants.Clinical Significance: The fracture strengths of the one-piece zirconia implants with a 3.7 mm diameter and a 15 abutment angle are above the chewing forces for the anterior intraoral region.

Static and Fatigue Mechanical Performance of Abutments Materials for Dental Restorations

“…The objective of this work was to conduct a comparative study and mechanically characterize new materials that are potential candidates for dental implantology. The obtained results agree with those of previous studies [ 19 , 22 , 23 ]. Sivrikaya et al found that zirconia abutments showed a lower stress distribution compared to that of titanium abutments, indicating that zirconia abutments may be a better choice for dental implants in patients who exhibit parafunctional habits.…”

“…Technical complications are quite common in implant-supported restorations and might strongly affect the patients’ comfort and satisfaction with their oral rehabilitation. Therefore, it is crucial to thoroughly examine the mechanical properties of restorative materials intended for use in implant dentistry, particularly when they are subjected to cyclic loading conditions [ 17 , 18 , 19 ].…”

Clinical outcomes of zirconia implants: a systematic review and meta-analysis

“…An in vitro study, published after the aforementioned review, evaluated and compared the fatigue resistance and fracture strength of zirconia implants of different diameters (3.0 and 3.7 mm), with straight or 15°-angled abutments. It was observed that all 3.0 mm diameter implants failed the fatigue test, with better performed demonstrated by the implants of wider diameter [ 67 ]. Specifically in relation to the implant that showed the highest prevalence of fracture, the Z-Look3 of diameter 3.25 mm, a failure analysis study had already recommended that this implant should no longer be used clinically, and that modification of the implant geometry was needed [ 65 ].…”

Zirconia Implants: A Mapping Review

“…Excessive implant thread depth is not recommended, as surgical placement might generate high bending forces on the implant body when engaging the bony perimeter of the osteotomy, especially in patients with dense bone (Figure 1) [48]. Additionally, zirconia implants with a narrow diameter (<3.75 mm) have been reported to have a higher incidence of fracture compared to implants with a regular diameter [49][50][51]. The purpose of this mapping review is to present the breadth of evidence to answer the question, "What do studies reveal about the efficacy of zirconia implants?"…”