A Completely Digital Workflow for Nanoceramic Endocrowns: A 5-Year Prospective Study

Abstract

Devitalized teeth are often challenging to restore due to the lack of coronal support and retention. New CAD/CAM materials and intra-oral scanning devices offer new possibilities to restore non-vital teeth in a simple and minimally invasive manner. The aim of this study was to evaluate the success of monolithic endocrowns using a digital workflow. MethodsTwenty-three patients requiring restoration of devitalised molars or premolars were included in the study. The preparation was scanned using an intra-oral scanner (Cerec Bluecam, Dentsply-Sirona) and a monolithic restoration was made from a nanoparticle resin-based hybrid composite (#10 GC Cerasmart [CS], #10 Lava Ultimate [LU]) or a polymer infiltrated ceramic (#10 Vita Enamic [VE]). At time of placement, after 6 months, 1 year and 5 years of function, radiographs were taken to evaluate the marginal integrity of the restoration and clinical pictures were taken to assess the quality of the restoration using the USPHS criteria. ResultsAfter 5 years, the restorative success rate was 70.8%, the restorative survival 87.5% and the tooth survival 91.6%. Four chippings (2 LU, 2CS), 3 fractures (3 LU) and 2 debonding of the restorations (2 CS) occurred. Also, 2 teeth were extracted after 5 years follow-up (2 VE), because of secondary caries and a root fracture. The USPHS ratings were high, except for the colour match, which was rated the lowest at all time intervals. ConclusionsNanoceramic endocrowns, made using a full-digital workflow, have an acceptable survival rate after 5 years. However, the complication rate was high. Patient satisfaction was scored using the OHIP-14 questionnaire, which is composed of 14 questions representing the patients' functional limits, physical pain, psychological discomfort, physical limitations, psychological limitations, social limitations and disability with the restoration. The occurrence of problems was rated on a Likert's scale from 0 (never) to 4 (very frequent), with a maximal OHIP 14-score of 56 points. StatisticsStatistics were performed using SPSS v26 (IBM, Armonk, NY, USA). Chi-square test was used to evaluate the survival and complication rate between the materials at the different time-points. Mann-Whitney U-test was used to compare the USPHS score between the different materials. Wilcoxon Signed Rank test was used to compare the OHIP-score over time. The level of significance was set at p=0.05.

Impact of CAD/CAM Material Thickness and Translucency on the Polymerization of Dual-Cure Resin Cement in Endocrowns

“…Among these, lithium disilicate glass is often considered the most suitable for endocrowns because of its excellent bonding ability and mechanical durability [ 34 ]. In addition to ceramics, resin composites are utilized for endocrown fabrication [ 39 ]. Their lower brittleness compared to traditional ceramics makes them a viable choice for endocrowns, particularly in patients with bruxism or in those requiring restoration to withstand heavier occlusal forces.…”

Indirect restorative systems—A narrative review

“…Overall, CAD/CAM resin‐matrix systems advantages include a homogeneous, dense, and reliable microstructure due to block/disk fabrication under an industrial environment of high temperature and pressure, 109,205 as well as high milling damage tolerance that may be linked to the polymeric content that provides an excellent machinability and small marginal gap, no need for post‐milling firing, easy adjustment and polishing, and repairability 202,203 . The mechanical properties of different resin‐matrix ceramic systems are dictated by their composition and microstructure, presenting a range of 150–270 MPa in the flexural strength and 10–30 GPa in the elastic modulus, 202,203,206,207 which support their indications for inlays, onlays, overlays, and tooth and implant supported crowns 208–210 …”

“…202,203 The mechanical properties of different resin-matrix ceramic systems are dictated by their composition and microstructure, presenting a range of 150-270 MPa in the flexural strength and 10-30 GPa in the elastic modulus, 202,203,206,207 which support their indications for inlays, onlays, overlays, and tooth and implant supported crowns. [208][209][210] The favorable biomechanical behavior of resin-matrix ceramics is determined by their polymeric content and low elastic modulus, which provides a favorable resilience and allegedly improves occlusal forces dampening and damage tolerance. [211][212][213][214][215][216] For tooth supported reconstructions, resin-matrix ceramics reconstructions potentially improve the biomechanical performance due to similar elastic modulus to dentin.…”

“…202,203,206,207 Partial coverage restorations and single crowns made by resin-matrix ceramics have shown a high survival rate in the midterm, higher than 90% after 3 to 5 years, with a significant increase in the marginal discoloration and surface roughness as the most frequently clinical complication over time, 208 along with chipping/ fracture of the material and debonding. [208][209][210] As implant-supported crowns, one resin-matrix ceramic material has shown very poor survival in the short term. 217 Longer clinical follow-up periods are needed to evaluate the mid-and long-term performance of resin-matrix ceramic restorations.…”

“…For tooth supported reconstructions, resin‐matrix ceramics reconstructions potentially improve the biomechanical performance due to similar elastic modulus to dentin 202,203,206,207 . Partial coverage restorations and single crowns made by resin‐matrix ceramics have shown a high survival rate in the mid‐term, higher than 90% after 3 to 5 years, with a significant increase in the marginal discoloration and surface roughness as the most frequently clinical complication over time, 208 along with chipping/fracture of the material and debonding 208–210 . As implant‐supported crowns, one resin‐matrix ceramic material has shown very poor survival in the short term 217 .…”