08/27/2010 Sealing Ability of New Generation Adhesive Systems in Primary Teeth: An In Vitro Study

Resident: J. Hencler
Date: 08/27/2010

Article title: Sealing Ability of New Generation Adhesive Systems in Primary Teeth: An In Vitro Study

Author(s): Atash, Vanden Abbeele

Journal: Pediatric Dentistry-26: 4, 2004

Major topic: Evaluation of restorative dental adhesives

Type of Article: In vitro study

Main Purpose:
To evaluate micro-leakage at enamel and cementum margins of class V resin-based comp restorations in primary molars using 6 sixth-generation adhesive systems and 2 fifth-generation systems. (XE=Xeno III; LP=Adapter Prompt L Pop; IB=I Bond; SB=Scotch Bond I; EP=Etch & Prime 3.0; AS=AdheSE; OB=Optibond Solo plus self-etch primer; CS=Clearfil SE Bond)

Overview of method of research:
120 primary teeth extracted for pulp disease or ortho reasons were used in this study. Cavity preps were made at the CEJ, half in enamel and half in cementum. Teeth were randomly assigned into 8 grps of 15 in which different adhesive systems were used. Methylene blue dye was applied for 24 hrs, than teeth were embedded in epoxy resin and section for microscopic examination. The degree of micro-leakage at the tooth/restoration margin was evaluated.

Findings:
In the enamel and cementum, the best seals were obtained with XE and LP, followed by CS, AS, IB, OB, SB, and EP. No significant differences were found in the micro-leakage degree b/t the cementum and enamel margins.

Key points in the article discussion:
Micro-leakage is defined as the undetectable passage of bacteria, fluids, molecules, or ions at a tooth/restoration margin and is considered to be a major factor influencing the longevity of a dental restoration causing marginal breakdown and recurrent caries. 3 adhesion mechanisms are currently used in modern adhesion procedures and differ in treatment of the smear layer. In the 1st grp, the smear layer is modified and incorporated in the bonding process. In the 2nd grp, the smear layer is completely removed (SB). In the 3rd grp (self-etching primers) the smear layer and the underlying dentin surface are partially demineralized w/o removing the dissolved smear layer remnants or unplugging the tubule orifices. In these systems the bonding agent is either applied after the self-etching primer (CS, EP, AS, IB) or mixed together w/ the self-etching primer before a single application (XE, LP). 3 step bonding systems are often considered to be too complicated and time-consuming, especially in pediatric dentistry, and tend to be replaced by “self-etching” or 6th generation adhesives. The advantage of these systems is that they etch and prime simultaneously. There is no discrepancy b/t the demineralization depth and resin infiltration depth since both processes occur at the same time. The rationale is to superficially demineralize the dentin and simultaneously penetrate with monomers, which can be polymerized in situ. These systems also are reported to reduce the incidence of post-treatment sensitivity.

Summary of conclusions:
Among the different self-etching products used in this study, Xeno III provided the best seal in enamel and cementum. The two single-step self-etch adhesives analyzed (Xeno III and L Pop) in this study, presented lower micro-leakage scores when compared to a total-etch system (Scotch Bond I) or self-etch, 2 step adhesive systems (OB). The authors conclude that different adhesive systems can affect the sealing ability of class V restorations.

Assessment of article:
Good article and review of current dental adhesive systems. It is important to be very familiar with all dental materials to insure successful tx outcomes.