Development of functional fillers as a self-healing system for dental resin composite

OBJECTIVES

To evaluate the incorporation of repairing capsules containing different monomers and polymerization modulators on the self-healing efficiency of an experimental photopolymerizable resin-based composite.

METHODS

Self-healing capsules containing different monomers and polymerization modulators were prepared by emulsion polymerization: TC_DHEPT (TEGDMA and DHEPT), BTC_DHEPT (Bis-GMA, TEGDMA, and DHEPT), and BTC_BPO (Bis-GMA, TEGDMA, and BPO). The capsules were analyzed through Fourier transform infrared spectroscopy and scanning electron microscopy. The capsules were added into experimental photopolymerizable resin composites establishing the following groups: ER (Control without capsules), ER+BPO, ER+BPO+TC_DHEPT, and ER+BTC_BPO+BTC_DHEPT. Filtek Z350 resin composite (3 M ESPE) was used as a commercial reference. The materials were tested for degree of conversion (DC), flexural strength (σf), elastic modulus (Ef), fracture toughness (virgin K_IC), self-healing efficiency (healed K_IC), and roughness. For statistical analysis, the significance value was established at an a = 0.05 level.

RESULTS

When compared to the control material, the incorporation of repairing capsules did not affect DC, σf, and Ef. Fracture toughness was statistically similar between the experimental groups (p ≤ 0.05). Healed K_IC was statistically different between the groups ER+TC_DHEP and ER+BTC_BPO+BTC_DHEPT; the self-healing efficiency was higher for ER+TC_DHEPT. Surface roughness was statistically similar among all groups.

CONCLUSIONS

The use of self-healing capsules promoted repair of the material. Studies with material aging after the self-healing process are necessary to better demonstrate the effectiveness of this system.

CLINICAL SIGNIFICANCE

The self-healing system seemed to be a promising technology to be used in self-repaired restorative materials, which may prevent restoration fractures.

Oral pigmented lesions in syndromic individuals: A systematic review

OBJECTIVE

To systematically integrate the available data published in the literature on oral pigmented lesions (OPL) associated with syndromes, summarizing the clinical and demographic features of the individuals.

MATERIALS AND METHODS

An electronic search was undertaken in six databases. Eligibility criteria were articles in English, Spanish, and Portuguese describing case reports or case series of OPL associated with syndromes. Data were aggregated and statistically evaluated.

RESULTS

About 108 articles reporting 149 cases of individuals with syndromes were identified. Among the affected individuals, nine syndromes were reported. The mean age at diagnosis was 35.93 years (0.41 to 83 years), with a predilection for white (n = 85/85.86%) female (n = 102/68.46%) individuals. As regards the number of lesions, 109 (73.15%) were multiple and 40 (26.85%) were single. Lip represented the anatomical location more affected (122 cases/38.01%), followed by the buccal mucosa (100 cases/31.15%). Brownish lesions accounted for 82 (69.49%) cases. The mean time of evolution was 10.52 years (0.16 to 56 years). OPL preceding diagnosis of the syndrome was observed in 111 (74.50%) cases.

CONCLUSIONS

Although these syndromes are uncommon, dentists should be able to recognize their manifestations, since oral manifestations can represent an important aspect in early diagnosis.