Y. KATOH1, M. SUZUKI1, T. OGISU1, C. KATO1, K. SHINKAI1, J. YAMAUCHI2, and T. ASAKURA3, 1The Nippon Dental University, Niigata, Japan, 2Kuraray Co., Ltd, Okayama, Japan, 3Tokyo Univerisity of Agriculture and Techolonogy, Japan |
Objectives: The purpose of
this study was to examine, histopathologically and immunohistochemically, the
effects of various experimentally developed adhesive resin systems containing
synthetic peptide derivatives (pA, pB) of dentin matrix protein 1 (DMP1) on the
wound healing process of exposed rat pulp.
Methods:The four
experimental groups were capped with a combination of the following primers and
bonding agents: commercially available Mega bond® primer (Kuraray,
MBP) 1 drop (30mg), CaCl2 (3.0mg) and synthetic peptide derivatives
(pA:1.2mg, pB:1.8mg) of DMP1; and commercially available Mega bond®
bonding agent (MBB), and experimental MBB containing 10wt% hydroxyapatite
(MB2). The two control groups were capped with MBP and MB2 (CONT1) and with
Dycal® (Dentsply Sankin) and MBB (CONT2). The rats were sacrificed
on the 14th post-operative day. The sample number of each group was 5. The
specimens were alternately stained with H-E, Hucker-Conn bacterial stain,
Reticulin silver impregnation and sABC method on TGF b1 and DMP1. The following
parameters were microscopically evaluated: pulp tissue disorganization (PTD),
inflammatory cell inflammation (ICI), reparative dentin formation (RDF), and
bacterial penetration (BP). The findings were graded using four legend scales.
Each result was statically analyzed using the Kruskal-Wallis H-test and then
Mann-Whitney U-test as a post-hock test (p<0.05).
Results: Especially in
group1, an extremely strong leading effect and three distinctive layers of RDF
were clearly observed. In group2, two distinctive layers of RDF were recognized
and formed at a relatively more outer area than in group1. But in group3, RDF
was located at a shallower area of the pulp and a distinctive layer structure
was not noticeable. Concerning DMP1 staining, groups1 and 4 showed relatively
stronger reaction findings than groups 2 and 3.
Conclusions: To summarize the results, the
experimental adhesive resin system of group1 was the most effective system in
initiating an early repair process after direct-pulp-capping.
|