All-ceramic, bi-layered crowns supported by zirconia implants: Three-year results of a prospective multicenter study

Clinical Oral Implants Res

Jung

et al. 2019

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Objectives To assess survival/success rates and patient‐reported outcome of zirconia‐based posterior single crowns (SCs) supported by zirconia implants in a prospective two‐center study after five years of observation. Material and methods Forty‐five patients were restored with 45 zirconia implant‐supported posterior SCs composed of zirconia frameworks hand‐layered with a leucite‐reinforced feldspathic ceramic. Survival rates of SCs were assessed and technical success was evaluated according to modified United States Public Health Care (USPHS) criteria. Furthermore, patient‐reported outcome measures (PROMs) were assessed by applying visual analog scales (VAS). Wilcoxon matched‐pairs signed‐rank test, mixed‐effects ordered logistic regression, and linear mixed models were used to evaluate time effects on response variables. Results Forty patients were available after a mean observation period of 61.0 ± 1.4 months. One SC had to be replaced, resulting in a Kaplan–Meier (KM) survival estimate for the SCs of 97.5 ± 2.47%. Since nine reconstructions showed at least in one category a major deviation from the ideal (five major chippings, four with increased occlusal roughness, one significant crevice, and one pronounced over‐contouring), the KM success estimate was 79.3 ± 5.8%. Incidence of chipping (n = 19) and occlusal roughness (n = 35) was frequent (p < 0.001). All PROMs at prosthetic delivery except for speech (p = 0.139) showed significantly improved VAS scores (81%–94%; p < 0.001) compared to pre‐treatment evaluations. Thereafter, no decrease in satisfaction could be observed until the 5‐year follow‐up (93%–97%). Conclusion Veneered zirconia‐based SCs supported by zirconia implants showed high survival rates and highly satisfied patients' needs. However, significant incidence of technical complications is compromising the clinical long‐term outcome for this indication.

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

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All‐ceramic single crowns supported by zirconia implants: 5‐year results of a prospective multicenter study

Spies

Clinical Oral Implants Res

Jung

et al. 2019

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“…As a consequence, for zirconia implants restored with veneered zirconia crowns in clinical studies, unacceptable rates of veneer chipping of up to 47% after up to 5 years have been reported [2,4,5,9], indicating stresses that were higher than the strength of the veneering ceramic itself or the bond strength between veneering ceramic and framework. It may be concluded that veneered zirconia is not suitable to restore zirconia implants.…”

Section: Introductionmentioning

confidence: 99%

Chewing simulation of zirconia implant supported restorations

Rohr

Journal of Prosthodontic Research

Müller

et al. 2019

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PURPOSE To test three potential prosthetic material options for zirconia implants in regard to their mechanical properties, loading and retention capacity as well as to record abrasion after chewing simulation followed by thermocyclic aging. METHODS Molar crowns (n = 96) of three different computeraided design/computer-aided manufacturing (CAD/CAM) materials were produced and cemented on zirconia implants (ceramic.implant, Vita) with a diameter of 4.5 mm. Monolithic zirconia (Vita YZ [YZ] with RelyX Unicem 2 Automix [RUN], polymer-infiltrated ceramic (Vita Enamic [VE]) with Vita Adiva F-Cem [VAF] and acrylate polymer (CAD Temp [CT]) with RelyX Ultimate [RUL]. Fracture load and retentive force of the crowns were measured after 24 h water storage at 37°C and after a chewing simulation followed by thermocyclic aging. Abrasion was recorded by matching stereolithography-data of the crowns obtained before and after chewing simulation. Additionally, the mechanical properties and bonding capabilities of the crown and cement materials were assessed. RESULTS Fracture load values were significantly highest for YZ > VE = CT. Retention force values did not differ significantly between the materials. The aging procedure did not affect the fracture load values nor the retention force significantly. Abrasion depth of the crowns was lowest for YZ followed by VE and CT. On unpolished crowns, abrasion of YZ and VE tended to be higher than on polished specimens. CONCLUSIONS Based on the obtained in-vitro results, all tested materials can be recommended for the use on zirconia implants, although CT is only approved for temporary crowns. The loading and retention capacity of the materials were not significantly affected by aging.

“…All reconstructions were produced with a zirconia framework (In-Ceram YZ, VITA Zahnfabrik), subsequently veneered (VM9, VITA Zahnfabrik), and adhesively cemented (RelyX Unicem 2 Aplicap, 3M Espe) (Figure 1e). Detailed information regarding manufacturing of the reconstructions, clinical prosthetic procedures, and F I G U R E 1 A patient case throughout the entire observation period (tooth position 46): (a) initial situation, (b) implant insertion, (c) guided bone regeneration, (d) immediate provisional reconstruction, (e) crown insertion, (f) 1-year follow-up, (g) 3-year follow-up, and (h) 5-year followoutcome measures (PROMs) were published in separate publications with a special focus on analyses of the prosthetic outcomes(Spies, Balmer, et al, 2017a;Spies et al, 2019;Spies, Kohal, Balmer, Vach, & Jung, 2017b). Patients were followed up annually from the first year to the fifth year after prosthetic insertions(Figure 1f-h).…”

mentioning

confidence: 99%

Zirconia implants restored with single crowns or fixed dental prostheses: 5‐year results of a prospective cohort investigation

Clinical Oral Implants Res

Spies

Kohal

et al. 2020

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Aim To evaluate the clinical and radiological outcomes of one‐piece zirconia implants restored with single crowns (SCs) or fixed dental prostheses (FDPs) over an observation period of 5 years in function. Materials and methods In a prospective cohort investigation with two investigational centers, one‐piece zirconia implants were placed in anterior and posterior sites. After a healing period of at least 2 months in the mandible and 4 months in the maxilla with immediate provisional reconstructions, the final all‐ceramic SCs or three‐unit FDPs were cemented. Patients were followed for 5 years. Clinical parameters and radiological measurements of the implants and the neighboring teeth were assessed. For the statistical analysis, linear mixed models were applied. Results A total of 71 implants were placed in 60 patients. Sixty‐three implants in 53 patients could be evaluated at the 5‐year follow‐up. Six patients with a total of seven implants were counted as dropouts. One implant did not achieve adequate osseointegration and had to be removed 5 weeks after implantation. The 5‐year survival rate was calculated as 98.4% (95% CI 91.6, 99.9). The mean overall marginal bone loss from implant placement to the 5‐year follow‐up was 0.7 ± 0.6 mm. After an initial mean marginal loss before loading the implants (0.7 mm), no further statistically significant change in marginal bone level (p = .458) could be observed. Conclusion The investigated one‐piece zirconia implant showed a high survival rate, very stable marginal bone, and mucosal margin levels after 5 years in function. Therefore, it can be considered safe and reliable for the reconstruction of implant‐supported SCs or FDPs over a mid‐term period.