The influence of different
splints and temporary
crowns upon the reliability of electric and thermal pulp-testing procedures was examined in 10 patients with vital maxillary central incisors and 10 patients with vital maxillary central incisors and 10 patients with unilateral
pulp necrosis of a central incisor. The pulp-testing procedures were: (1) Bofors Pulp Tester, (2) Siemens Sirotest, (3) heated
guttapercha, (4)
ice, and (5)
carbon dioxide snow (Odontotest). The
splints or temporary
crowns were: (1)
silver cap
splint, (2) acrylic cap
splint, (3) Hawley orthodontic plate, (4) Saur's arch bar, (5) orthodontic bands, (6)
stainless steel crown, and (7)
stainless steel crown with labial surface removed. A reliable electrometric pulp response could only be elicited if the pulp tester was applied directly upon enamel and preferably upon the incisal edge. In this instance
metal splints or partial steel
crowns applied to the tooth had no effect on the pain threshold. A false positive reaction in case of
pulp necrosis was only elicited when the
electrode was placed directly upon
metal which contacted neighboring vital teeth. The use of
ice and heated
guttapercha appeared to be of limited value, due to inconsistent pulp responses.
Carbon dioxide snow gave a reliable response, unless applied on the incisal edge.