The Importance of Dentin Collagen Fibrils on the Marginal Sealing of Adhesive Restorations

Abstract

SUMMARYThis study evaluated the importance of the union between dentin collagen and three different adhesive materials. Sixty Class V restorations were prepared on the buccal and lingual surfaces of 30 recently extracted human premolars, with the cervical margins in dentin and the occlusal margins in enamel. These restorations were distributed to three groups of 20 cavities each based on the employed adhesive system used: Group A: Single Bond; Group B: Prime&Bond NT; Group C: One Coat Bond. Each group was subdivided according to dentin treatment: 1) manufacturers' adhesive protocol and 2) removal of the collagens fibers (total etch + sodium hypochlorite 5% for two minutes) + adhesive protocol. After the restorations were completed, the teeth were stored in saline solution (24 hours/37°C), subjected to thermal cycling, washing and scoring according to dye penetration. Dye penetration was evaluated, with the numbers ranging from 0 (no infiltration) to 3 (greatest infiltration). WhenThe results of this research showed that, with regard to marginal seal, collagen fibrils were not essential to obtaining an optimal adhesive performance. Deproteinization should be considered as a bonding pre-treatment.

Wetting ability of an acetone/based etch rinse adhesive after NaOCl-treatment

“…Several factors influence on biodegradation of the collagen matrix and/or hydrophilic resin components within the hybrid layer. Some of them are incomplete penetration/infiltration of resin into dentin substrate (2) and hydrolysis of unprotected collagen (3,4), resulting in continued degradation of resindentin interface (2). To avoid this biodegradation different strategies have been proposed, such as the use of metalloproteinases inhibitors (5) and demineralized collagen removal (6).…”

Influência do tempo e meio de armazenamento na resistência adesiva e microinfiltração de sistemas adesivosão de sistemas adesivos.

“…metizar uma situação mais próxima do processo físico-químico dinâmico, com trocas minerais entre tecidos duros dentais e fluidos bucais. 12 Devido às inúmeras pesquisas na área de adesão à dentina que levaram a elucidação da contribuição de cada um dos componentes destes materiais, altos valores de resistência adesiva inicial têm sido alcançados, porém a estabilidade e, consequentemente, a durabilidade da adesão continuam sendo uma incógnita tendo visto que os componentes hidrofílicos, como o HEMA, que compõe o adesivo e possibilitam sua infiltração no tecido dentinário para formação de uma camada híbrida satisfatória, apresentam a estrutura química sujeita a hidrólise a longo prazo. 13,14 Neste estudo, a hipótese avaliada foi verificar "in vitro" se o tratamento químico dinâmico de pH, mimetizando as condições iônicas dos minerais presentes na saliva, sem induzir os espécimes à cárie, seria capaz de remineralizar, junto à utilização de solução fluoretada, os poros no interior e áreas subjacentes à camada híbri-da através da formação de fosfato de cálcio na forma de hidroxiapatita e fluorapatita após 30 dias de armazenamento, comparando com o armazenamento dos espécimes pelo mesmo tempo em água, através da resistência de união e de forma ilustrativa da interface adesiva infiltrada com solução de nitrato de prata.…”

Impact of chemical agents for surface treatments on microhardness and flexural strength of root dentin

“…11 Additionally, by applying NaOCl on the acid-demineralized dentin, 12 the exposed collagen is removed, 5 and the wettability of the bonding substrate 9 and resin infiltration may be facilitated.…”

“…8 Nevertheless, degradation of resindentin bonds occurs over time due to hydrolysis of the collagen fibrils within the hybrid layer that are not fully infiltrated by resin monomers. 1,9 Stable hybrid layer and preservation of adhesion can be reached by controlling the degradation of the denuded collagen matrix. 10 Therefore,…”