Occlusal veneer restoration treatment outcomes of cracked tooth syndrome: A 22.4-month follow-up study.

OBJECTIVES: The aims of this clinical study were to investigate success rate, vital pulp survival rate, tooth survival rate and patient-reported masticatory ability by evaluating the pain symptoms and signs of the cracked teeth as well as Index of Eating Difficulty (IED) and Oral Health Impact Profile-14 (OHIP-14) questionnaire after cracked teeth were restored with occlusal veneers. MATERIALS AND METHODS: 27 cracked teeth of 24 patients with cold and/or biting pains without spontaneous/nocturnal pains were recruited in this study. The cracked teeth were restored with occlusal veneers fabricated by lithium disilicate ceramic. Cold test and biting test were used to evaluate pain signs. IED and OHIP-14 questionnaire were used to evaluate masticatory ability. FDI criteria was used to evaluate restorations. The paired Wilcoxon test was used to analyze significant differences of detection rate of pain signs, OHIP scores and IED grade before and after restorations. Kaplan-Meier survival curve was used to describe the success rate, vital pulp survival rate, and tooth survival rate. RESULTS: 27 cracked teeth were restored with occlusal veneers with average of 22.4-month follow-up. Two cracked teeth had pulpitis and pain signs of the other cracked teeth completely disappeared. OHIP total scores were significantly reduced after treatment. Scores of 'pain', 'occlusal discomfort', 'uncomfortable to eat', 'diet unsatisfactory' and 'interrupted meals' reduced significantly after treatment. After treatment, IED grades of 25 vital teeth were significantly lower than those before treatment. FDI scores of 25 restorations except for 2 teeth with pulpitis were no greater than 2. The 12 months accumulated pulp survival rate of the cracked teeth was 92.6%. The 12 months accumulated tooth survival rate was 100%. The success rate at the latest recall was 92.6%. CONCLUSION: Occlusal veneer restorations with success rate of 92.6% and the same pulp survival rate might be an effective restoration for treating the cracked teeth. CLINICAL RELEVANCE: The occlusal veneer restorations might be an option for treating the cracked teeth when cracks only involve enamel and dentin, not dental pulp.

Application of digital technology in the repair of functional and aesthetic defects in patients with acid erosion and severe attrition: a case report.

Noncarious lesions, a multifactorial condition encompassing tooth attrition, abrasion, and erosion, have a surge in prevalence and required increased attention in clinical practice. These nonbacterial-associated tooth defects can compromise aesthetics, phonetics, and masticatory functions. When providing full-arch fixed occlusal rehabilitation for such cases, the treatment strategy should extend beyond by restoring dentition morphology and aesthetics. This report details a complex case of erosive dental wear addressed through a fully digital, full-arch fixed occlusal rehabilitation. A 4D virtual patient was created using multiple digital data sources, including intraoral scanning, 3D facial scanning, digital facebow registration, and mandibular movement tracing. With a comprehensive understanding of the masticatory system, various types of microinvasive prostheses were customized for each tooth, including labial veneers, buccal-occlusal veneers, occlusal veneers, overlays, inlays, and full crowns, were customized for each tooth. The reported digital workflow offered a predictable diagnostic and treatment strategy, which was facilitated by virtual visualization and comprehensive quality control throughout the process.

A novel porous silica-zirconia coating for improving bond performance of dental zirconia.

OBJECTIVES: To coat a zirconia surface with silica-zirconia using a dip-coating technique and evaluate its effect on resin-zirconia shear bond strength (SBS). METHODS: A silica-zirconia suspension was prepared and used to coat a zirconia surface using a dip-coating technique. One hundred and eighty-nine zirconia disks were divided into three groups according to their different surface treatments (polishing, sandblasting, and silica-zirconia coating). Scanning electron microscopy (SEM), energy dispersive X-ray (EDX), and X-ray diffraction (XRD) were used to analyze the differently treated zirconia surfaces. Different primer treatments (Monobond N, Z-PRIME Plus, and no primer) were also applied to the zirconia surfaces. Subsequently, 180 composite resin cylinders (Filtek Z350) were cemented onto the zirconia disks with resin cement (RelyX Ultimate). The SBS was measured after water storage for 24 h or 6 months. The data were analyzed by two-way analysis of variance (ANOVA). RESULTS: SEM and EDX showed that the silica-zirconia coating produced a porous layer with additional Si, and XRD showed that only tetragonal zirconia was on the silica-zirconia-coating surface. Compared with the control group, the resin-zirconia SBSs of the sandblasting group and silica-zirconia-coating group were significantly increased (P<0.05). The silica-zirconia coating followed by the application of Monobond N produced the highest SBS (P<0.05). Water aging significantly reduced the resin-zirconia SBS (P<0.05). CONCLUSIONS: Dip-coating with silica-zirconia might be a feasible way to improve resin-zirconia bonding.

Fabrication, characterization and properties of DHA-loaded nanoparticles based on zein and PLGA.

This study focused on the feasibility of delivering docosahexaenoic acid (DHA) via zein/ Poly(lactic-co-glycolic) acid stabilized nanoparticles (ZPDNPs). ZPDNPs with good encapsulation efficiency, water solubility, and chemical instability were prepared by the antisolvent precipitation method. The structure and interaction force of ZPDNPs was evaluated using transmission electron microscopy, circular dichroism, X-ray powder diffraction, and FTIR. The stabilities of ZPDNPs for heating, pH, NaCl aqueous solution were also investigated. The results showed that ZPDNPs can improve the water solubility (750-fold), salt tolerance, and heat-resistant processing stability of DHA. The ZPDNPs had high encapsulation efficiency (84.6%) and stability after 35 days of storage. The simulated digestion of the gastrointestinal tract can change particle size, interface potential, and aggregation state of different DHA nanoparticles. The bioavailability of ZPDNPs was 4.2 ~ 5.6-folds higher than free DHA. Overall, a useful method for ZPDNPs formulation was developed for the delivery of DHA.

Enamel microstructural features of bovine and human incisors: A comparative study.

OBJECTIVE: Multiple dental researches show that bovine teeth are potential alternatives to human teeth. However, whereas cattle are herbivore, humans are omnivorous. Consequently, we sought to compare the enamel microstructures of bovine and human teeth in relation to their functional similarity. MATERIALS AND METHODS: Crowns of human and bovine teeth were first cut longitudinally, horizontally and tangentially. The appearance of enamel microstructures under the three dimensions were then analyzed using a scanning electron microscope (SEM). RESULTS: Human and bovine teeth have relatively different enamel microstructure. Bovine enamel exhibits transitional zones between adjacent HSBs bands. In addition, it has abundant interprisms interwoven with prisms. CONCLUSION: The teeth of the bovine and humans have a similar evolutionary origin, but the differences are attributed to dietary adaptation. Given the closeness of enamel microstructure of two animals' teeth, the bovine teeth could be utilized as an excellent alternative to human teeth in dental researches.

Interaction of ACP and MDP and its effect on dentin bonding performance.

OBJECTIVES: The study investigated the solid reactants of amorphous calcium phosphate (ACP) nanoparticles with 10-methacryloyloxydecyl dihydrogen phosphate (MDP) in ethanol-aqueous solution, and the effect of ACP-MDP suspension as a novel primer on dentin micro-tesnisl bond strengths (MTBS) prior to application of self-etch adhesives. MATERIALS AND METHODS: The ACP nanoparticles were synthesized. The solid reactants of ACP nanoparticles with MDP ethanol-aqueous solution were analyzed by TEM, SEM, XRD and AFM. After the ACP-MDP complexes were attacked by alkaline, acidic and self-etch adhesive challenges, they were analyzed with TEM. The polished mid-coronal dentin surfaces of six third molars were treated with ACP-MDP suspension, 5% MDP solution or not (served as control), and thoroughly water-sprayed. The pretreated dentin surfaces were applied with a self-etch adhesive (Clearfil S3 Bond) and placed with a composite resin (Clearfil Majesty). After 24 h, the resin-bonded samples were cut into multiple beams before the MTBS tests were performed. The failure modes were determined by a stereo-microscopy. The pretreated dentin surfaces were analyzed by SEM. The resin-dentin interfaces were analyzed with TEM. RESULTS: The ACP nanoparticles in the MDP ethanol-aqueous solution at certain molar ratio of Ca:MDP (0.12:1) could self-assemble into ACP-MDP complexes consisting of nanolayering structures. The ACP-MDP self-assembly went from ACP nanoparticles, beaded structures, and twig-like structures to networks. The ACP-MDP complexes can be resistant to adhesive challenge, but not to alkaline and acidic challenges. ACP-MDP complexes possessed a similar modulus of elasticity to dentin, and were stable at least for 3 months. Furthermore, the dentin surfaces treated with ACP-MDP suspension could significantly increase the dentin MTBS when compared with control and those treated with 5% MDP solution (P < 0.05). CONCLUSION: The ACP-MDP suspension at certain molar ratio of Ca:MDP (0.12:1) could be self-assembled into ACP-MDP complexes consisting of nanolayering structures, and could be used as a novel primer to greatly improve the dentin bond strengths.