Technique Sensitivity: Biological Factors Contributing to Clinical Success with Various Restorative Materials

Abstract

Since the 1950s, clinicians have relied on various formulations of Ca(OH)2 to stimulate dentin bridge formation. Various studies (Kozlov and Massler, 1966; Massler, 1967; Brännström, 1978; Cox et al., 1987; Snuggs et al., 1993) have demonstrated that pulp healing and dentin bridging can occur against a pH spectrum of materials. Recent studies (Akimoto et al., 1998; Cox et al., 1998, 1999; Tarim et al., 1998; Kitasako et al., 1999; Hafez et al., 2000) have reported successful pulp healing and dentin bridging using adhesives for direct capping of exposed pulps. However, others (Costa et al., 1997; Stanley and Pameijer, 1997; Pameijer, 1998; Hebling et al., 1999; Carvalho et al., 2000) have reported unsatisfactory results when exposures were direct-capped with adhesives. Biological and technical factors, or a combination of both, might be postulated to explain these differences. Recent studies have demonstrated that biological success is dependent upon proper hemorrhage control at the exposure site. This review explores the differences and common factors influencing successful dentin bridging, focusing on data derived from animal studies conducted according to ISO usage guidelines for cavity preparation and material placement. In the past, there has been concern that etching of vital dentin leads to immediate pulp death due to low pH. Recent studies have reported that acidic cements cause breakdown of only the smear layer and fail to seal the restoration interface, leading to inflammation and necrosis. A properly hybridized dentinadhesive interface provides a "bacteriometic" seal to both dentin and pulp tissues. Recent ISO usage studies have shown a high incidence of dentin bridging with adhesives following proper hemorrhage control and removal of both operative debris and biofilm at the dentin-pulp interface by agents such as NaOCl. These are important technique-sensitivity factors to be considered for pulp healing and dentin bridge formation.

A paradigm shift in endodontic management of immature teeth: Conservation of stem cells for regeneration

“…The literature is replete with the finding that if disinfection can be performed effectively, pulp tissue can heal and new dentin bridge will form. 44 Pulp tissue in immature teeth with open apex has larger volume of pulp tissue with a rich blood supply which may explain why it is more potent in defending infection and to heal. Farsi et al found a success rate of 93% with evidence of continued root growth after using MTA as direct pulp capping to treat carious exposure in young permanent teeth.…”

Efficacy of polyphasic calcium phosphates as a direct pulp capping material

“…1,2 However, Ca(OH) 2 -based materials have no adhesive properties toward either dentin or overlaid resins, and they provide poor sealing of the exposed site. 3,4 Since their physical properties are low, they are prone to dissolution by acid-etching 5 and demonstrate low durability.…”

Effect of CO2 laser irradiation on wound healing of exposed rat pulp

“…Especially, in the case of capping methods using an adhesive system without calcium hydroxide, inadequate hemostasis can cause microleakage by hampering bonding hybridization of the dentin substrate. [1][2][3][4][5] In author's laboratory, direct pulp capping with adhesive resin of human, 6-9 monkey, [10][11][12][13][14][15][16][17] and rat teeth 18,19 consistently employed a combination of 10% sodium hypochlorite (NaClO) gel and alternate irrigation with 6% NaClO and 3% hydrogen peroxide (H 2 O 2 ). These were undertaken to improve dentin bond strength, and to achieve hemostasis, disinfection, and debridement of the exposure site, and irrigation of the internal dentinal tubules.…”