Electrosurgical pulpotomy in primates--a comparison with formocresol pulpotomy.

The purpose of this study was to contrast histologically the pulp response to formocresol with the response to electrosurgical pulpotomy in a primate model. Both the primary and permanent incisors and molars were treated. Coronal pulp amputation was accomplished mechanically. The remaining pulp stumps were treated by either formocresol or momentary electrosurgery exposure. Results were evaluated at one hour, one week, and two months postoperatively. Results with the conventional formocresol treatment were consistent with other studies showing favorable pulp response. The electrosurgical approach produced no furcation or periapical involvement and exhibited no evidence of necrosis in the apical two-thirds of the root. Histologically, in this study electrosurgery pulpotomy had as favorable a tissue response as the conventional formocresol treatment for the time studied. The formocresol pulpotomy recently has come under close scrutiny due to possible systemic distribution of formocresol with attendant potential toxic effects. 1-11 Buckley’s original concept to detoxify the intermediate and end products of pulpal infection and inflammation was based upon a nonbiologic empirical theory. 1-3’8’ 12 The technique has been used with varying degrees of clinical success for years.1-3’ 5. 6. 13-15 Surveys suggest that the formocresol pulpotomy in primary teeth is considered the treatment of choice in a majority of pedodontic departments in North America.1 The degree of clinical success has ranged widely. 14 Success, however, must incorporate the possible systemic effects of formocresol and potential involvement of permanent succedaneous teeth. Several studies have shown that formocresol or one of its metabolites appears outside the tooth both locally and systemically. 4-11 Systemic manifestations must be considered a possibility since formocresol is a material to~ic to cells and tissue. 1-7’ 9, 16 Enamel surface defects on permanent successors are an additional potential problem. 5 Alleged biocompatible alternatives have been advocated including the use of calcium hydroxide17’ 18 glutaraldehyde,16 and electrosurgery. 1~-~1 Various texts and papers have suggested electrosurgical pulpotomy for years. 19-21 There is a paucity of histological data concerning pulpal tissue response to electrosurgery. The only available information presents conflicting results and these appear to be techniquedependent. 18, 22 The electrosurgical pulpotomy has merit. It is much quicker than the formocresol approach. It is self-limiting--pulpal penetration is only a few cell layers deep. There is hemostasis and good visualization without chemical coagulation and no systemic involvement. The purpose of this study was to evaluate electrosurgical pulpotomy at the histologic level. The results of the standard formocresol technique were contrasted to that of electrosurgical pulpotomy in primary and young permanent teeth in pigtail monkeys. Methods and Materials Three Macaca nemestrina monkeys (two male, one female) designated M1, M~, M3", age approximately two years, were selected because of incomplete development of permanent teeth and reduced amount of resorption of primary teeth. The animals were tranquilized with ketamine hydrochloride (10 mg) prior to treatment and then given mg/cc thiamyial sodiumb intravenously until fully sedated. Preoperative radiographs were made. Rubber dam was applied using quadrant isolation and the field was swabbed with alcohol sponges. All equipment was sterilized prior to use. All teeth were prepared with a 330 bur in a high-speed handpiece until the enamel was penetrated and the pulp chamber exposed. A #2 round bur was used to amputate ~ Primates from the Regional Primate Research Center, University of Washington, supported by NIH Grant #RR00166. b Surital, Parke-Davis, Division of Warner Lambert Co., Morris Plains,