Monkey pulpal response to an MMA-based resin cement as adhesive luting for indirect restorations.

PURPOSE: The objective of this study was to evaluate the pulpal response to a newly-developed MMA resin cement (MultiBond, Tokuyama) when used for adhesively luting composite resin inlays. MATERIALS AND METHODS: Cervical cavities were prepared in monkey teeth. The teeth were randomly divided into 3 groups. In the experimental group, a self-etching primer and a resin cement were applied to the cavities, and then hybrid composite inlays (Estenia, Kuraray) were inserted using freshly mixed resin cement. In the other groups, a zinc oxide/eugenol cement (Eugedain, Showa Yakuhin Kakou) or a glass-ionomer cement (Fuji II, GC) was used to fill the cavity. The teeth were then extracted after 3, 30, and 90 days, fixed in 10% buffered formalin solution, and prepared using routine histological techniques. Five-mum-thick sections were stained with hematoxylin and eosin, or Brown & Brenn gram stain for bacterial observation. Histopathological reactions in the pulp tissue and bacterial penetration along the cavity walls were assessed using a standardized score. RESULTS: No serious inflammatory reactions in the pulp, such as necrosis or abscess formation, were observed in any of the experimental periods, except for 1 case after 30 days, in which a pulpal exposure was suspected. Disarrangement of the odontoblast layer and deposition of reparative dentin were the major reactions observed in this specimen. No bacterial penetration along the cavity walls was detected. The monkey pulpal response and in vivo sealing ability of the MMA resin cement in combination with the self-etching primer was considered as good as that of the glass-ionomer cement. CONCLUSION: The new MMA resin cement showed acceptable biological compatibility to the monkey pulp when used to adhesively lute composite resin inlays.

Biocompatibility of a flowable composite bonded with a self-etching adhesive compared with a glass lonomer cement and a high copper amalgam.

This study evaluated the pulpal response and in-vivo microleakage of a flowable composite bonded with a self-etching adhesive and compared the results with a glass ionomer cement and amalgam. Cervical cavities were prepared in monkey teeth. The teeth were randomly divided into three groups. A self-etching primer system (Imperva FluoroBond, Shofu) was applied to the teeth in one of the experimental groups, and the cavities were filled with a flowable composite (SI-BF-2001-LF, Shofu). In the other groups, a glass ionomer cement (Fuji II, GC) or amalgam (Dispersalloy, Johnson & Johnson) filled the cavity. The teeth were then extracted after 3, 30 and 90 days, fixed in 10% buffered formalin solution and prepared according to routine histological techniques. Five micrometer sections were stained with hematoxylin and eosin or Brown and Brenn gram stain for bacterial observation. No serious inflammatory reaction of the pulp, such as necrosis or abscess formation, was observed in any of the experimental groups. Slight inflammatory cell infiltration was the main initial reaction, while deposition of reparative dentin was the major long-term reaction in all groups. No bacterial penetration along the cavity walls was detected in the flowable composite or glass ionomer cement except for one case at 30 days in the glass ionomer cement. The flowable composite bonded with self-etching adhesive showed an acceptable biological com- patibility to monkey pulp. The in vivo sealing ability of the flowable composite in combination with the self-etching adhesive was considered comparable to glass ionomer cement. Amalgam restorations without adhesive liners showed slight bacterial penetration along the cavity wall.

Pulpal response to a fluoride-releasing all-in-one resin bonding system.

Pulp tissue reactions to a fluoride-releasing all-in-one resin bonding system (Reactmer Bond and Reactmer Paste) in non-exposed monkey teeth were histopathologically evaluated at three, 30, and 90 days after restoration. No serious inflammatory reactions of the pulp, such as necrosis or abscess formation, were observed. At 90 days in the Reactmer group, odontoblastic change and inflammatory cell infiltration were not observed, and slight irritation dentin formation was formed. The pulpal response of the Reactmer group was minimally different from that of the control group. Consequently, the Reactmer system was determined as being biologically compatible with vital pulps.