Aspects of bonding between resin luting cements and glass ceramic materials

Inflammatory and immunological aspects of dental pulp repair.

Understanding outcomes of the interaction between a dental material and tooth tissue is important in terms not only of biocompatibilty but also of the potential for the material to modulate the response of the tissue. This interaction is influenced by many factors, including the chemistry of the material and any of its eluted components or degradation products, and the manner in which the tissue responds to these agents. Past studies of this interaction have primarily been aimed at identifying cytotoxic effects. More recently, investigations have focused on specific cellular responses, and in particular, on understanding how the materials themselves actually may contribute to regenerative processes in the tooth. Recent work has demonstrated the solubilization of proteins from dentin exposed to certain materials, such as calcium hydroxide, mineral trioxide aggregate, and acidic solutions that relate to those used in dentin bonding agents, with the subsequent modulation by these proteins of gene expression in odontoblast-like cells. This work suggests that dentin bridge formation under such materials may be stimulated through this process. Thus, there is much merit in examining both how new dental materials can be developed and how more traditional ones can be modified to preferentially stimulate regenerative processes when preferred. This review summarizes current knowledge about the potential beneficial effects derived from the interaction of dental materials with the dentin-pulp complex, as well as potential future developments in this exciting field.

Can interaction of materials with the dentin-pulp complex contribute to dentin regeneration?

Influence of ceramic thickness and curing mode on the polymerization shrinkage kinetics of dual-cured resin cements.

Resin-based cements have been frequently employed in clinical practice to lute indirect restorations. However, there are numerous factors that may compromise the clinical performance of those cements. The aim of this literature review is to present and discuss some of the clinical factors that may affect the performance of current resin-based luting systems. Resin cements may have three different curing mechanisms: chemical curing, photo curing or a combination of both. Chemically cured systems are recommended to be used under opaque or thick restorations, due to the reduced access of the light. Photo-cured cements are mainly indicated for translucent veneers, due to the possibility of light transmission through the restoration. Dual-cured are more versatile systems and, theoretically, can be used in either situation, since the presence of both curing mechanisms might guarantee a high degree of conversion (DC) under every condition. However, it has been demonstrated that clinical procedures and characteristics of the materials may have many different implications in the DC of currently available resin cements, affecting their mechanical properties, bond strength to the substrate and the esthetic results of the restoration. Factors such as curing mechanism, choice of adhesive system, indirect restorative material and light-curing device may affect the degree of conversion of the cement and, therefore, have an effect on the clinical performance of resin-based cements. Specific measures are to be taken to ensure a higher DC of the luting system to be used.

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Correlation between clinical performance and degree of conversion of resin cements: a literature review

The influence of porcelain thickness and opacity on the polymerization of two dual activated (microfine and hybrid) and one light irradiated (hybrid) resin cements was assessed by hardness measurements. The surface microhardness values of the upper and lower surface of 1 mm thick resin cement specimens were determined. Specimens were polymerized using 40s irradiation beneath different thicknesses and opacities of porcelain discs. The results showed that increasing the thicknesses and opacity of the porcelain produced a statistically significant decrease in microhardness of the resin-based cements. The effect of attenuation is less for the microfine cement than for the hybrids. In the case of hybrid cements, the light activated material performed better than the dual activated cement.

The attenuation of radiation by porcelain and its effect on polymerization of resin cements

Unilateral loss of mandibular continuity creates problems in prosthetic reconstruction. For dentate patients, palatal guide ramps or mandibular guide flange prostheses are indicated. Edentulous patients are much more difficult to retrain in mandibular movements, but complete dentures designed with stabilising occlusal contacts can be successful in compensating for the deviation. Three case reports are presented.

Mandibular guidance prostheses following resection procedures: three case reports.

Immunohistochemical evaluation of endothelial cell adhesion molecules in human dental pulp: Effects of tooth preparation and adhesive application

Constuction of the obturator prostheses and providing the patient's comfort with them are very difficult. Primary and the most important stage for these prostheses is to perform a proper impression. A 55-year-old edentulous Turkish female patient with a congenitally maxillary defect was rehabilitated with an open hollow obturator prosthesis. After the preliminary impression was completed, a metal frame suitable with the maxillary defect was constructed manually and used for making the impression of the defect area. After the first part of the obturator was finished, second part which separates nasal cavity and oral cavity was constructed by the aid of the bulb. When constructing an obturator prosthesis, making a detailed impression from the defect area can be performed by the aid of a metal frame, and an intraorally shaped extension that separates oral cavity from nasal cavity might be more effective for adaptation of the prosthesis.

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Rehabilitation of a congenital palatal defect with a modified technique: a case report.

PURPOSE To evaluate the influence of provisional luting cements on the bonding performance of a resin-based self-adhesive luting cement to dentin vs that of currently used resin-based luting agents with different adhesion strategies. MATERIALS AND METHODS Forty-five prepared human molars were randomly and equally divided into three main groups according to the type of provisional luting cement applied: eugenol-containing provisional cement (Temp Bond, Kerr), eugenol-free provisional cement (Temp Bond NE, Kerr), and control where the provisionalization step was omitted. Each group was further subdivided into 3 groups based on the category of adhesive systems/ luting materials used: a two-step etch-and-rinse system (Single Bond/RelyX ARC; 3M ESPE) (RX), a two-step self-etching system (Clearfil Liner Bond 2V/ Panavia F; Kuraray) (PF), and a self-adhesive luting cement (Rely X Unicem; 3M ESPE) (RU). Finally, 9 groups of 5 teeth each were prepared for the microtensile test. RESULTS Two-way analysis of variance (ANOVA) and post-hoc Bonferroni tests revealed that definitive luting cement, provisional luting cement, and the interactions of these two factors had significant influences on dentin bond strength. The highest bond strength was obtained for PF (32.05 MPa), followed by RX (26.57 MPa) and RU (16.56 MPa) for the controls. Contamination with either eugenol-containing or eugenol-free provisional cement significantly decreased the bonding effectiveness of RX (19.08 and 19.69 MPa, respectively) and PF (14.21 and 16.67 MPa respectively) to dentin (p 0.05). Eugenol in provisional luting cement did not produce material-related alterations in the bonding performance of the resin luting cements tested (p > 0.05). CONCLUSION Based on these results, the self-adhesive cement which was not influenced by the provisional cement application may be promising. However, long-term laboratory and clinical performance of this cement needs to be assessed before recommending it as an alternative to the technically more demanding approaches. Moreover, an effective surface cleansing procedure is critical to achieve a successful bond between the contaminated dentin and luting cement.

Ufuk Hasanreisoglu

Papers

The attenuation of radiation by porcelain and its effect on polymerization of resin cements

Mandibular guidance prostheses following resection procedures: three case reports.

Immunohistochemical evaluation of endothelial cell adhesion molecules in human dental pulp: Effects of tooth preparation and adhesive application

Rehabilitation of a congenital palatal defect with a modified technique: a case report.

Bonding effectiveness of a self-adhesive resin-based luting cement to dentin after provisional cement contamination.