Clinical Performance of Lithium Disilicate Glass-Ceramic Onlays For The Treatment of Tooth Defects

Abstract BackgroundThe aim of this study was to assess the clinical performance of lithium disilicate glass-ceramic onlays for the treatment of tooth defects and to evaluate the clinical performance and whether they are worth more extensive use as that of the full crown. MethodsPatients who received treatment by lithium disilicate glass-ceramic onlays at the Western China Hospital of Stomatology were recalled after 1~4 years. The clinical performance and patients’ satisfaction of onlays for various tooth defects, cracked or uncracked teeth and endodontically treated or vital teeth were retrospectively evaluated with a combination of modified United States Public Health Service Criteria and questionnaire survey. Statistical analysis was performed by using the chi-squared test, Kaplan–Meier analysis and Log-rank test (a = 0.05) where appropriate. ResultsA total of 154 patients with 166 onlays were recalled for clinical examination. Of the 166 onlays examined, 65 (39.19%) were occlusal onlays, 92 (55.42%) were proximal-occlusive onlays and 9 (5.42%) were buccal-or lingual-occlusal onlays. The clinical performance of O and PO onlays was not significantly different (P > 0.05), according to USPHS Criteria. Kaplan-Meier analysis showed that the 4-year survival rate of O and PO onlays was 95.4% and 97.8%, respectively while there was no failure happened in buccal-or lingual-occlusal onlays. Log- rank test showed that the kinds of defects/onlays, tooth vitality and tooth crack had no influence on the survival rate (P > 0.05). The overall satisfaction rate was more than 98%.ConclusionsThis medium-term analysis indicated that lithium disilicate glass-ceramic onlays achieved satisfactory clinical performance for the restoration of different tooth defects. The survival rate of onlays was comparable to that of full crown. Different kinds of tooth defects, tooth vitality and tooth crack did not influence performance.Trial registrationThe study was approved by the Medical Ethics Committee of West China Hospital of Stomatology of Sichuan University with the approval number: WCHSIRB-D-2021-300. Consent to participate was not applicable.