ABSTRACT
Objective:To compare the wear resistance between dentin and dental restoration material in vitro.Methods:The friction and wear behaviors of natural tooth dentin respectively against highly polished polymer ceramic,glass ceramic and zirconia were investigated in an artificial saliva test environment by UMT-2 friction and wear testing machine.Worn surface morphology was observed by scanning electron microscopy(SEM),roughness was measured by roughness instrument,the rigidity value was weighed by electronic balance.Results:The roughness of the 3 materials was similar to that of dentin(P ＞ 0.05),the rigidity of dentin was less than that of the 3 materials (P ＜ 0.05).After friction and wear test,the abrasion quantity of dentin respectively against the 3 materials was less than that of the materials (P ＜ 0.05).There was positive correlation between the wear loss and the hardness of the 3 materials and dentin(r =0.846).The mass loss of the dentin against Poly Ceramic after grinding abrasion was the closest among the 3 materials.Conclusion:Different materials have varying degrees abrasion against dentine.The Polymer Ceramic has closer abrasion performancez with dentin than the other 2 materials.
ABSTRACT
Little attention has been paid to the toxicity of silver amalgam fillings, which have been used over the centuries in Dentistry. Amalgam particles may accidentally and/or traumatically be embedded into the submucosal tissue during placement of a restoration and perpetuate in such area. This article presents a case of amalgam tattoo and investigates whether it is related to the patient's repeated episodes of sinusitis. The patient was a 46-year-old woman with a 2 mm diameter radiopaque lesion in the right oral mucosa detected on a panoramic radiograph and presented as a black macula clinically. A complete surgical resection was carried out. The histopathological examination revealed deposits of dark-brownish pigments lining the submucosal tissue with adjacent lymphocytic inflammatory infiltrate and multinucleated giant cells phagocyting pigments. There was a negative staining for both iron and melanin. One year after lesion removal, the patient reported that the sinusitis crises had ceased after repeated episodes for years. It may be speculated that the inflammatory process related to amalgam tattoo seems to lead to a local immune response that causes sinusitis because it enhances the human leukocyte antigen DR (HLA-DR) tissue expression.
Subject(s)
Female , Humans , Middle Aged , Dental Amalgam/adverse effects , Mouth Diseases/complications , Pigmentation Disorders/complications , Sinusitis/etiology , Chronic Disease , Foreign Bodies/complications , Foreign Bodies/pathology , Giant Cells/pathology , HLA-DR Antigens/analysis , Lymphocytes/pathology , Mouth Diseases/diagnosis , Phagocytosis/physiology , Pigmentation Disorders/diagnosisABSTRACT
The aim of this study was to examine Streptococcus mutans biofilm growth on both aged and non-aged restorative dental resins, which were submitted to therapeutic irradiation. Sixty-four disks of an esthetic restorative material (Filtek Supreme) were divided into 2 groups: aged group (AG) and a non-aged group (NAG). Each group was subdivided into 4 subgroups: non-irradiated and irradiated with 10Gy, 35Gy, and 70Gy. The biofilms were produced by Streptococcus mutans UA159 growing on both AG and NAG surfaces. The colony-forming units per mL (CFU/mL) were evaluated by the ANOVA and the Tukey LSD tests (α=0.05). AG presented smaller amounts of CFU/mL than the NAG before irradiation and after 10Gy of irradiation (p<0.05). AG irradiated with 35 and 70Gy showed increased amount of bacterial biofilm when compared to non-irradiated and 10Gy-irradiated disks (p<0.05). The exposure to ionizing radiation at therapeutic doses promoted changes in bacterial adherence of aged dental restorative material.
O objetivo deste estudo foi avaliar a formação do biofilme de Streptococcus mutans crescido em resina restauradora envelhecida e não-envelhecida, submetidas à radiação terapêutica. Sessenta e quatro discos do material restaurador Filtek Supreme foram divididos em 2 grupos: grupo envelhecido (AG) e grupo não-envelhecido (NAG) e cada grupo foi dividido em 4 sub-grupos: não-irradiado e irradiado com 10Gy, 35Gy e 70Gy. O biofilme de S. mutans UA159 foi produzido na superfície de ambos os discos AG e NAG. As unidades formadoras de colônia/mL (UFC/mL) foram avaliadas por ANOVA e teste de Tukey (α=0,05). O grupo AG demonstrou menores quantidades de UFC/mL que o grupo NAG antes da radiação e após a radiação de 10Gy (p<0,05). Os sub-grupos AG irradiados com 35 e 70Gy demonstraram aumento na quantidade de biofilme quando comparado aos não irradiados e irradiados com 10Gy (p<0,05). A exposição à radiação ionizante nas doses terapêuticas promoveu mudanças na aderência bacteriana no material restaurador.