In vitro Simulation of Periodontal Ligament in Fatigue Testing of Dental Crowns

Abstract

<jats:title>Abstract</jats:title><jats:p> Objective Fatigue testing of restorative material has been appreciated as an appropriate method to evaluate dental restorations. This study aims to investigate the influence of periodontal ligament (PDL) simulation on fatigue and fracture tests results of zirconia crowns.</jats:p><jats:p> Materials and Methods A standard tooth preparation for all ceramic zirconia crown was made on a typodont mandibular molar. The prepared master die was duplicated using epoxy resin to produce 40 replicas. PDL simulation was made by surrounding the root of 20 dies with a 0.3-mm thick silicon layer. The other 20 specimens had no PDL simulation. Zirconia crowns were fabricated using computer-aided design/computer-aided manufacturing technology and cemented to the epoxy resin dies. Ten crowns from each group were subject to chewing simulation with simultaneous thermocycling (5–55°C). All specimens were then loaded until failure in universal testing machine.</jats:p><jats:p> Statistical Analysis Statistical analysis was conducted using SPSS software. Shapiro–Wilk test confirmed the normal distribution of data. Descriptive statistic was performed and differences between the groups were analyzed using paired samples t-test.</jats:p><jats:p> Results All fatigued crowns survived chewing simulation; no failure was observed after finishing simulation. The highest mean fracture load recorded was 3,987 ± 400 N for the no fatigue/no periodontal simulation group. Comparing the mean fracture load of the two groups with periodontal simulation and the two groups with no periodontal simulation showed no statistically significant difference (p &gt; 0.5).</jats:p><jats:p> Conclusion Considering the testing set-up applied in this study, simulating PDL using resilient materials does not affect the in vitro survival and fracture resistance of zirconia crowns.</jats:p>

The effects of a periodontal ligament analogue on occlusal contact forces

“…PDL analogues, typically dental impression or reline materials, 15,16,18 have been evaluated for applicability and incorporated into experiments with unnatural opposing contacts such as 6-mm-diameter ceramic and 8-mm-diameter stainless steel indenters. 19 Not only do non-tooth antagonists (the spherical indenters, for example) define, and simplify, the geometry of the occlusal contact interactions, but the ceramic vs. the stainless steel indenters also differ in their associated contact friction forces. Although the emphasis is on the rigid vs. PDL results (Figures 4 and 5), Figure 3 clearly illustrates the effects of occlusal forces on PDL response.…”

Influence of instrument taper on the fracture susceptibility of endodontically treated maxillary premolars

“…Consequently, the load applied by the indenter only influences the specimen until it fails, which results in no significant differences between the groups with and without PDL simulation (22). Undeniably, the cushioning effect through artificial PDL simulation might be an influential parameter during fatigue testing because of the relatively low load compared with the load applied during fracture test (23).…”

An in vivo evaluation of clear aligners for optimal orthodontic force and movement to determine high-efficacy and periodontal-friendly aligner staging

“…5 A). Before the mechanical testing, all samples were preconditioned by applying 10 tensile-compression cycles with linear loading and unloading at 0.2 mm/min, as previously reported [ 24 , 25 ]. The value of the preconditioning cycle was selected based on the repeatability of the mechanical response of the PDL.…”