An evaluation of pulpal therapy in primary incisors.

In 45 children (18-54 months), 28 pulpotomies, 26 indirect pulp therapies, and 27 pulpectomies were completed in primary incisors with 58 incisors acting as controls. Using clinical and radiographic evaluations, the success rate of pulpotomies, indirect pulp therapies, and pulpectomies did not differ statistically from comparable primary molar rates. Incisor pulpotomy success was 85.7% (mean follow-up 43.8 months), indirect pulp therapy success 92.3% (mean followup 42 months), and pulpectomy success 77.7% (mean followup 45.5 months). Canal calcifications were common in pulpotomies and indirect pulp therapies. Pulpectomies were affected adversely by preoperative root resorption, but not affected by preoperative trauma nor presence of a preoperative radiolucency. Retained ZOE was found in 73.3% of the exfoliated pulpectomies. The data supported indirect pulp therapy or pulpotomy as the treatment of choice for deep incisor caries unless the dental pulp was necrotic. Pulp therapy often is indicated for maxillary primary incisors due to extensive caries or trauma. This procedure may involve either partial or complete extirpation of the infected pulpal tissue or indirect pulp therapy. Previous research involving primary teeth evaluating pulpotomies, pulpectomies, and indirect pulp therapy has dealt mainly with primary molars. These studies have mostly evaluated formocresol pulpotomies in primary molars. Success rates have ranged from 70 to 90% depending on the method of evaluation (Law and Lewis 1964; Magnusson 1970; Rolling and Thylstrup 1975). Fewer studies have evaluated pulpectomies. Coil et al. (1985) showed primary molar pulpectomy success rates of more than 80% while Gould’s (1972) pulpectomy success was 82%. Nirschl and Avery (1980) found 94.1% success in treating primary molars and young permanent incisors with indirect pulp therapy. Studies of pulpal treatment in primary incisors usually have dealt with case histories of individual teeth (Finn 1967; Spedding 1973). However, Flaitz et al. (1987) reported on 57 primary incisor pulpotomies and 87 pulpectomies in teeth that required pulp therapy due to caries or trauma. The incisor pulpotomies were successful in 75.5% of the cases while the pulpectomies were successful in 86.2%. Complete resorption of the paste filler occurred in all the pulpotomies, but in only 55.2% of the pulpectomies. The purpose of the present study was to: (1) evaluate the success of primary incisor pulpotomies, indirect pulp therapy, and one-appointment pulpectomies; and (2) determine factors that influenced the success of the pulp therapy. Additional assessment was done to evaluate exfoliation of treated teeth, incidence of enamel defects in succedaneous teeth, incidence of canal calcifications in treated teeth, and retention of paste filler material after exfoliation. Materials and Methods A total of 45 patients from a private dental practice were included in the the research design. One investigator (JAC) completed 28 pulpotomy procedures, 26 indirect pulp therapy procedures, and 27 pulpectomies in the primary incisors of 30 children. In 15 children, 58 primary incisors were utilized as controls where no pulpal treatment was performed. Children included in this retrospective study were chosen from a patient pool which had adequate preoperative and postoperative radiographs of their incisors, and had been seen for regular recall visits over an 11-year period (July, 1976, to June, 1987). The criteria for selecting a tooth for a pulpotomy procedure were: (1) absence of a systemic medical contraindication; (2) radiographically deep caries approximating the pulp, but no evidence of pathologic root resorption nor periapical pathology; (3) no sign mobility nor soft tissue pathology; (4) no history trauma; (5) presence of a clinical pulp exposure following caries removal; and (6) moderate hemorrhage in the 178 PULP THERAPY IN PRIMARY INCISORS: Coil et al. pulp chamber, but no sign of necrosis extending into the root canal. The criteria for an indirect pulp therapy procedure were the same as the aforementioned I-4 with no clinical pulp exposure. Criteria for pulpectomy selection were based on radiographic or clinical signs of pulpal necrosis. In 90% of the cases there was evidence of a draining sinus tract. Other indications for pulpectomy were copious hemorrhage that was uncontrollable or complete lack of hemorrhage upon entrance into the pulp chamber. Radiographically, 22% of the pulpectomy candidates had a periapical radiolucency or incipient pathologic root resorption. A tooth which had been traumatized and discolored was treated with a pulpectomy if a sinus tract was present or if it had the aforementioned radiographic findings. Contraindications for a pulpectomy were signs of extensive internal or external root resorption or lack of adequate bone support as evidenced by excessive mobility. The formocresol pulpotomy procedure involved isolating the tooth whenever possible with a rubber dam following local anesthesia. If the removal of the soft carious dentin with a slow-speed large round bur revealed a pulp exposure or if, on close inspection, a pinpoint exposure was found, the pulpotomy was started. A #330 high-speed bur was used to open the pulp chamber. A #6 or 8 slow-speed round bur was used to remove the coronal pulp to a depth of 5-7 ram. After the hemorrhaging was controlled by applying pressure with dry cotton pellets, a cotton pellet slightly moistened with Buckley’s formocresol (formaldehyde 19%, cresol 35%, glycerin 17.5% -Sultan Chemists Inc, Englewood, NJ) was placed in the pulp chamber for rain. A thick mix of ZOE was used to fill the pulp chamber. A final restoration then was completed either at the same visit or at a subsequent one. The indirect pulp therapy procedure was done following the removal of carious brown leathery dentin. A layer of dentin remained that may have been soft or stained, but its aggressive removal would have revealed a pulp exposure. At this point calcium hydroxide in the form of Dycal ~ (LD Caulk Co, Milford, DE) was placed over the dentin. The final restoration was placed at the same appointment. The pulpectomy procedure was similar to the pulpotomy procedure until the pulp chamber was entered. Root canal files starting with size #20-30 up to size #4050 were used to clean the canal. The files were inserted to a resistance point short of the apex. After each size file was withdrawn, sodium hypochlorite was used to irrigate the canal. After the final irrigation, cotton pellets and paper points were used to dry the canal. One paper point or cotton pellet slightly moistened with Buckley’s fomocresol was placed in the canal for 5 rain. A thick mix of zinc oxide and eugenol then was condensed into the canal with large root canal lateral condensers. Total treatment time was approximately 20-30 rain and all the treatments were done by the same investigator (JAC). Evaluation of the pulpal therapy’s success was done by three investigators. One investigator (JAC) evaluated the clinical success of all the teeth at routine recall appointments. Periapical radiographs usually were exposed every 6-18 months. Success of treatment for the treated teeth was based on a combination of the clinical and radiographic findings. For a tooth to be considered clinically successful, the following criteria were applied: (1) no gingival swelling or residual sinus tract; (2) no sign of purulent exudate expressed from the gingival margin; (3) no abnormal mobility considering the exfoliative state of the tooth; and (4) no history of pain. Radiographic criteria for success were based on the following: (1) no internal resorption of the root canal for pulpotomies or indirect pulp therapy teeth; (2) no external resorption of the root other than that considered normal exfoliation; and (3) a radiolucency resolving seen in postoperative films. An overall rating of success meant that the treated tooth met all the above clinical and radiographic criteria. The radiographic assessment method for the pulpotomies, indirect pulp therapies, and untreated controls was based on a double-blind method first tested by Nassof (1981; Fig I -next page), In the present study, the individual preand postoperative radiographs were mounted beneath clear celluloid plastic sheets. Using typewriter correction Liquid Taperaser® (The Joseph Dixon Crucible Co, Jersey City, NJ), the clinical crown and pulp chamber were obscured. The films were assorted randomly. Two judges (MR, PS) independently rated the pulpal health of the incisors on each film after first standardizing their criteria of assessment on 85 anterior radiographs not included in the study. Then they combined their radiographic assessment with the clinical findings to come up with an overall rating of success or failure for the pulpotomies and indirect therapy-treated teeth, and either normal or abnormal for the controls. In cases of disagreement, the raters reviewed the radiographs and reached agreement or, if necessary, rated the tooth as abnormal. The radiographic assessment procedure for the pulpectomies differed from that employed for the pulpotomies and the indirect pulp therapy group. In assessing the radiographic success of pulpectomies, one investigator (JAC), viewed all the preoperative and postoperative films sequentially. This finding was combined with the clinical assessment for an overall .rating of success or failure. Pediatric Dentistry: September, 1988 ~ Volume I0, Number 3 179 FIG 1. Radiographs showing the doubleblind radiographic assessment method for pulpotomies and indirect pulp therapies, (a, left) Preoperative film, 20 months, (b, right) Same film with typewriter correction fluid applied to obscure pulp chamber contents prior to evaluation, (c, L. left) Patient at 53 months showing failure of maxillary left lateral pulpotomy and success of right lateral which had the common finding of canal calcification. The central incisors were treated with indirect pulp therapies; the left was rated a radiographic failure, the right a success, (d, L. right) Same film as c. with opaque fluid applied that was used to evaluate radiographic pulpal health.