Maxillary Nerve Discharge Induced by Cavity Preparation

Abstract

In this experiment 12 dogs were used, and a series of 2-3 experimental trials was performed on each animal.It was found that the discharge from the mandibular nerve during grinding of dentinal tissues of a lower canine of a dog was strongly affected by the instruments used, i.e., a conventional dental engine (diamond point) and an air turbine (diamond point) (Fig. 1). All through 7 seconds of the grinding procedure of an upper canine from enamel to dentin, the discharge from the maxillary nerve was the most dominant in the case ground from the mesio-distal direction and, on the contrary, the least from the disto-mesial direction. In addition, the following results were found: Carborunduum disk induced the most dominant nerve responses, and according to the order of steel bur, carbide bur, and diamond point, the responses reduced. The last one showed the smallest response among the instruments used (Fig. 2). A B X:ivv~i I;~, i i-ti r t iii a C a 1s. .--Responise of the mianidibular nerve induced by grinding of tooth. A = spontanieous discharge; B discharge under grinding by conventional handpiece (7,000 rpm, diamond point); C discharge under grinding by air turbine (300,000 rpm, diamond point). spikes sec 50 -In 1Cm a: 00 ,v-1E bucco-lingual direction E3 mesio-distal direction El linguo-buccal direction disf -mesial direction j L S~d s t corborundum disk steel bur carbide bur diamond point conventional handpiece air turbine (7,000rpm) (300,000rpm) FIG. 2. Response of the maxillary nerve in cavity preparation. This histogram indicates a discharge pattern induced by grinding of left upper canine of a dog by various cutting instruments, and also indicates differences of response in cases cutting the tooth from various directions.Additional information is available on request to the authors.