Marginal Adaptation of Flowable vs Sonically Activated or Preheated Resin Composites in Cervical Lesions

PURPOSE

To investigate marginal integrity of restorations applied with preheated and non-preheated composite, flowable composite, sonically activated composite, and a new thermo-viscous bulk-fill composite using near-infrared technology for preheating, in class V cavities of human molars.

MATERIALS AND METHODS

Standardized cavities were prepared on the buccal surfaces of 60 human mandibular molars and restored with one of the following resin composite materials after application of an etch-and-rinse adhesive (OptiBond FL, Kerr): non-preheated or preheated conventional composite (Filtek Supreme XTE, 3M Oral Care), preheated thermo-viscous composite (VisCalor bulk, Voco), soncially activated composite (SonicFill 3, Kerr), or flowable composite (Filtek Supreme XTE Flowable, 3M Oral Care) applied in bulk or as a lining material using the snow-plow technique. After light curing and polishing, the percentage of continuous margins (PCM) of the restorations in enamel and dentin was assessed using SEM both before and after thermomechanical loading (TML). TML was carried out with 3000 thermal cycles (5°C-50°C) and a simultaneous mechanical stress application with 1.2 million load-cycles (1.7 Hz, 49 N) in a computer-controlled masticator. Non-parametric statistical analysis was performed using Wilcoxon, Kruskal-Wallis, and Mann-Whitney U-tests (α = 0.05).

RESULTS

All groups revealed a significant decline in marginal integrity after TML in both enamel and dentin. Although the flowable group in enamel and the snow-plow group in dentin showed the highest PCM before TML, the differences between the groups were compensated after TML.

CONCLUSION

All of the tested composites and application methods showed similar marginal integrities after thermomechanical loading and can be recommended for clinical implementation.

Rehabilitation of Worn Dentition with CAD-CAM Restorations: A Case Report

PURPOSE

To describe the digital workflow applied for restoring a severely worn dentition with minimally invasive CAD/CAM resin nano-composite restorations.

MATERIALS AND METHODS

A 40-year-old male in good general health and with full-arch dentition suffered from dentin hypersensitivity and wanted to improve the esthetics of his worn anterior teeth. The dental wear can be described as general, grade 3, according to the Tooth Wear Index,27 with more wear in maxillary than in mandibular teeth. Signs and symptoms were typical for a chemical type of wear, with some mechanical wear also apparent. No functional problems, eg, impaired chewing, were present. On the OHIP-49 questionnaire, the patient expressed a reduced quality of life. The goal of the treatment was to reconstruct the anatomical form of the teeth as far as possible, thereby also improving quality of life. Due to the rather large volume of lost tooth tissue per tooth, indirect treatment using CAD/CAM resin nano-composite restorations (LAVA Ultimate, 3M Oral Care) was applied.

RESULTS

The seating of the CAD/CAM resin nano-composite restorations (LAVA Ultimate, 3M Oral Care) restorations was considered precise.

CONCLUSION

In the treatment of severe tooth wear, the described digital workflow using CAD/CAM restorations for occluding restorations and direct composite materials in the esthetic zone is a potential treatment modality that is workable and minimally invasive.

Prospective Study on CAD/CAM Nano-Ceramic (Composite) Restorations in the Treatment of Severe Tooth Wear

PURPOSE

The aim of this prospective study was to evaluate the clinical performance of minimally invasive, CAD/CAM nano-ceramic (composite) restorations in patients with severe tooth wear, the effect of the restorative treatment on the oral health-related quality of life (OHRQoL), and the etiology of tooth wear as a risk factor for restoration failure.

MATERIALS AND METHODS

Patients with generalized severe tooth wear were included. Restorations (LAVA Ultimate, 3M Oral Care) were cemented (RelyX Ultimate, 3M Oral Care) on all teeth and were evaluated after 1 month and 1 year. OHRQoL was assessed via questionnaires at baseline and after 1 year. Differences were evaluated (paired t-test). Two mechanical tooth-wear lesions resulting from tooth-tooth contact, and 3 chemical tooth wear lesions resulting from intrinsic or extrinsic acids dissolving natural hard tooth substance, were evaluated to assess the etiology of tooth wear in association with restoration failure using multilevel logistic regression analyses (p < 0.05).

RESULTS

Twenty-one patients (age: 41.7 ± 10.4 years) were evaluated after 1 year (13.5 ± 1.2 months). 568 indirect CAD/CAM restorations were placed. None were replaced or lost. Twelve were repaired and 10 were refurbished. Success rates were 100% to 97.2%. Questionnaires showed a significant positive impact of the treatment on OHRQoL (p < 0.001). The presence of mechanical lesions did not pose a higher risk for restoration failure (p = 0.78). The presence of chemical lesions showed a lower risk of restoration failure (p = 0.002).

CONCLUSION

The use of minimally invasive, CAD/CAM nano-ceramic (composite) restorations in the restorative treatment of severely worn dentitions showed satisfactory results in the short term.