Newly developed resinous direct pulp capping agent containing calcium hydroxide (MTYA1-Ca).
OBJECTIVE
The aim of this study was to evaluate a newly developed resin (MTYA1-Ca) for direct pulp capping.


METHODS
The powder of MTY1-Ca is composed of 89.0% microfiller, 10.0% calcium hydroxide and 1.0% benzoyl peroxide and was mixed with liquid (67.5% triethyleneglycol dimethacrylate, 30.0% glyceryl methacrylate, 1.0% o-methacryloyl tyrosine amide, 1.0% dimethylaminoethylmethacrylate, and 0.5% camphorquinone). The shear bond, diametral tensile, bending and compressive strengths were measured. The alkaline activity of the elute dissolved from MTYA1-Ca was calculated. Cell viability by MTT assay and alkaline phosphatase (ALPase) activity were evaluated from dental pulp fibroblast reaction to the eluate dissolved from MTYA1-Ca. Histopathological studies of the response to exposed dental pulp of beagle dogs were completed with Dycal as a control.


RESULTS
The physical properties of MTYA1-Ca were significantly superior to those of Dycal. It was impossible to measure these properties with Dycal because of poor physical properties. Both MTYA1-Ca and Dycal maintained high levels of alkaline activity (pH 10.96-12.20) over the 168-h duration of the study. Cell viability by MTT assay in the intact eluate of MTYA1-Ca was significantly higher than that of Dycal, whilst ALPase showed no difference between MTYA1-Ca and Dycal. A dentine bridge formed more slowly under MTYA1-Ca than under Dycal, but similar amounts had formed at 90 days.


CONCLUSIONS
MTYA1-Ca has the potential to be used as a direct pulp capping material.
Niinuma
A
A
Department of Endodontics, Nihon University School of Dentistry at Matsudo, Chiba, Japan. atsukon@mascat.nihon-u.ac.jp
D000704:Analysis of Variance; D000818:Animals; D002126:Calcium Hydroxide / Q000633:toxicity*; D002478:Cells, Cultured; D016009:Chi-Square Distribution; D019245:Compressive Strength; D003782:Dental Pulp / Q000166:cytology / Q000187:drug effects*; D003785:Dental Pulp Capping / Q000379:methods*; D004285:Dogs; D004338:Drug Combinations; D005347:Fibroblasts / Q000187:drug effects*; D008422:Materials Testing; D008689:Methacrylates / Q000737:chemistry / Q000633:toxicity*; D018583:Pliability; D013718:Tensile Strength; D014443:Tyrosine / Q000031:analogs & derivatives* / Q000737:chemistry / Q000633:toxicity
D004338:Drug Combinations; D008689:Methacrylates; C069151:methacryloyl tyrosineamide; D014443:Tyrosine; D002126:Calcium Hydroxide