Untreated Control Teeth Research Articles

Quantitative assessment of intrapulpal axon response to orthodontic movement

Nerve fiber changes are of potential concern during tooth movement. Quantitative and qualitative assessments using electron microscopy of nerve fibers entering the tooth give an indication of change in the remainder of the pulp. Eight healthy mandibular first premolars were selected from four subjects, so that respective pairs had open apices and short-term movement, open apices and long-term movement, closed apices and short-term movement, and closed apices and long-term movement. These were compared to forty-nine untreated control teeth. No significant differences in myelinated or unmyelinated axon number were observed between experimental and control teeth. Altered myelin figures, possibly degenerating, were observed in only a small percentage of axons in teeth moved for a short period. No alterations were observed in teeth moved for long periods. It is concluded that intrapulpal axon alterations are minimal and not progressive with conservative orthodontic tooth movement.

Root resorption in bicuspid intrusion. A scanning electron microscope study.

Apical root surfaces covered by cellular cementum are rapidly subjected to resorption under orthodontic loads of varying magnitude and duration. Within the experimental parameters employed, the intrusive forces applied to the teeth produced a striking increase in root resorption compared with the control teeth. The amount of resorption increased markedly with the duration of the force, and to a lesser extent with the magnitude of the appliance activation. After 70 days, cellular cementum repair accompanied the continuing resorption. Little variation was detected in the susceptibility of different patients to root resorption in the experimental teeth. The same intrusive load applied for the same duration to similar teeth produced a corresponding degree of root resorption in various individuals. On the other hand, there were individual differences in the amount of resorption on untreated control teeth. There is a need to extent our understanding of the periodontal ligament and its associated tissues which provide the basis for our professional services. Clearly, root resorption and the capacity for repair are orthodontic facts of life. In the current climate of technological innovation great emphasis has been given to cephalometrics and appliance mechanics, which provide the orthodontist with the clinical stimulus of visual and tactile involvement. This paper is presented as a contribution to our knowledge of the unseen biological consequences which accompany that orthodontic treatment.

Studies of Sargenti's technique of endodontic treatment: six-month and one-year responses

Response to Sargenti's technique of endodontics was investigated in the treatment of teeth with induced pulpitis and of teeth with induced necrosis and periapical pathosis in Macaca speciosa monkeys. Histologic examination at six months and a year after treatment showed that periapical lesions that ranged from apical periodontitis to osteomyelitis developed in all teeth treated for pulpitis, whereas none of the untreated control teeth showed any periapical inflammation. In teeth with induced necrosis, both the treated and untreated control teeth showed basically the same periapical response.

Studies of Sargenti's technique of endodontic treatment: short-term response in monkeys

The short-term response to Sargenti's technique of endodontics was investigated in the treatment of inflamed and necrotic pulps induced in the teeth of two Macaca speciosa monkeys. A histologic examination at one month showed periapical inflammation of all but one apex of the teeth treated for pulpitis, whereas none of the untreated control teeth had periapical inflammation. Both the treated and untreated necrotic teeth had basically the same periapical responses. The short-term response to Sargenti's technique of endodontics was investigated in the treatment of inflamed and necrotic pulps induced in the teeth of two Macaca speciosa monkeys. A histologic examination at one month showed periapical inflammation of all but one apex of the teeth treated for pulpitis, whereas none of the untreated control teeth had periapical inflammation. Both the treated and untreated necrotic teeth had basically the same periapical responses.

Sealing of Developmental Pits and Fissures. VI. Arrestment of Caries with a Fluoride-Containing Polyurethane System

A polyurethane-adhesive coating containing fluoride salts (Epoxylite 9070) was applied to carious and all other surfaces of rat molars. Arrestment of carious lesions was achieved. Depending upon the criteria employed for differentiating arrested and active lesions, 31 to 46% of the lesions were arrested in the treated group, while only 14 to 22% were arrested in untreated control teeth. The system was designed to promote the sequence of events that normally occur in the spontaneous regression of an active carious lesion to an inactive or arrested lesion. The system was proposed as a possible alternative or adjunct to the conventional treatment of caries with cavity restorations.

Radicular pulpotomy of category III pulps. Part III. Histologic evaluation

Twenty-two sound or symptom-free restored teeth (indicated for extraction) of patients 18 to 60 years of age were subjected to radicular pulpotomy and immediate root canal filling. 2 Eight contralateral teeth served as untreated controls. The histologic evaluation led to these results. The untreated control teeth showed regressive changes in the apical third of the radicular pulps consisting of the disappearance of the odontoblasts, von Korff fibers, and the subodontoblastic vascular network starting at the apex and gradually ascending. The regression increased with age. All the treated teeth showed a vital remaining pulp free of inflammation and necrosis. One month postoperatively capping was effected by dentinal chips encapsulated by a fibrotic tissue. Osteodentin matrix formation had begun around advanced dentin chips and at discrete sites of the dentinal walls, while at other areas modeling resorption took place. The frequency and extent of dentinoclasia seemed to depend on the height of the pulpotomy, but they never constituted a clinical problem since dentinoclasia would repair with osteodentin. The remaining tissue had the characteristics of loose connective tissue. Three months postoperatively, the remaining pulp size had been reduced by osteodentin deposition along the dentinal walls and around the dentinal chips thus forming a more or less complete seal. Calcific obliteration depended on the presence of a dentinal plug and its proximity (3 to 5 mm.) to the apex. This was associated with a progressive fibrosis of the remaining pulp tissue in the absence of inflammatory changes. In the light of the favorable biologic results obtained, it may be justified to introduce radicular pulpotomy into daily practice under the conditions that its specific indications for category III pulps are respected and its exacting techniques applied.