Effects of distance from the pulp and thickness on the hydraulic conductance of human radicular dentin

The purposes of this study were: (1) to measure the effect of distance from the pulp on the hydraulic conductance of human radicular dentin; (2) to determine the influence of dentin thickness on the rates of fluid flow; and (3) to attempt to correlate dentinal tubule densities and diameters with root dentin hydraulic conductance. Dentin slabs prepared from extracted, unerupted, human third molar teeth were placed in a split-chamber device to permit quantitation of fluid filtration rate (hydraulic conductance). In the SEM portion of the study, dentinal tubule numbers and diameters were recorded. The results indicated that radicular dentin hydraulic conductance decreased with distance from the pulp and with increasing dentin thickness. Tubule density and diameter correlated well with the measured hydraulic conductances. The relatively low hydraulic conductance of outer root dentin makes it a significant barrier to fluid movement across root structure.     

Caries experience in urban Tanzanian children 1973-84

In 1973 and 1984 the caries status of 624 and 394 children, respectively, was recorded in an urban area of northern Tanzania where the water fluoride content was 2.0-3.5 ppm. Although slightly different scoring criteria were used, the data showed very low levels of caries, and little evidence of increases in caries experience over the 10-yr period. The distribution of caries lesions was markedly skewed, such that a minority of individuals account for most of the caries. The levels of caries were low by international standards and equivalent to those found in children from low fluoride areas of Tanzania.     

Ultrastructural findings in oral Kaposi's sarcoma (AIDS)

Ten biopsies of oral Kaposi's sarcoma were examined histologically and ultrastructurally. Histologically, early and late tumor stages could be differentiated. On the ultrastructural level, endothelial-like and spindle-shaped tumor cells were revealed. Tumor cells associated with vessel-like spaces showed partly interrupted basal membranes, Weibel-Palade bodies, desmosomes and tight-junctions, while spindle-shaped cells lacked these ultrastructural features of endothelial cells. Within the cytoplasm of endothelial-like cells, aggregates of tubular structures were observed. Histological and ultrastructural findings in oral Kaposi sarcoma are comparable to those of such other organs as skin and intestines. The ultrastructural findings indicate an endothelial origin, at least of endothelial-like tumor cells.     

An evaluation of the clinical analgesia/anesthesia efficacy on acute pain using the high frequency neural modulator in various dental settings

The purpose of this study was to evaluate the effectiveness of high frequency neural modulation as a substitute for traditional local anesthesia in various dental procedures. This double-blinded study was done to evaluate patient comfort and degree of satisfaction as well as manageability of pain control by the operator during the dental procedures. Procedures included restorations, tooth extractions, root planing, pulp extirpation, and temporomandibular joint therapy. In the experimental group, favorable responses ranged from 0.0% to 92.8%, depending on the procedures. An overall favorable rating of 71.8% was given by the experimental group, and an overall favorable response of 8.5% was given by the placebo group.     

Tooth eruption and craniofacial development in congenital hypothyroidism: report of case

The long-term effects of severe hypothyroidism on craniofacial growth and dental development are illustrated in this case. It is apparent that given a favorable diet, the primary dentition can persist for a long period (early childhood to at least the age of 19) without the development of dental caries. It is also clear that the dental structures can still respond to the effects of L-thyroxine at a relatively late age, with the exfoliation of primary dentition and eruption of the secondary dentition. Impacted mandibular second molars appear to be rare. The lack of proper growth of the mandible and failure of normal resorption of the internal aspect of the ramus associated with deposition of bone on the external aspect with the development of normal-size teeth, resulted in a lack of space for the eruption of mandibular second molars. The impaction of the mandibular second molars in this patient seems to be caused by a dissociation of ramus growth and dental development, resulting in insufficient space for proper eruption of these teeth.     

Effects of citric acid treatment on pedicle flap coverage of localized recession

Citric acid conditioning of denuded roots prior to laterally positioned pedicle flap (LPPF) coverage may increase the likelihood of reattachment, but no controlled studies to determine the efficacy of the procedure in managing naturally occurring defects in humans have been reported. This investigation compared the effects of LPPF root coverage with and without citric acid (pH1) pretreatment in a group of patients with gingival recession and associated denuded roots. Thirty-six patients participated in the study. Eighteen received LPPFs without citric acid pretreatment and 18 received LPPFs with citric acid pretreatment. Gingival recession and sulcus depth were measured preoperatively and 30, 60 and 90 days after the surgical procedure. LPPFs both with and without citric acid pretreatment reduced significantly the amount of exposed root, but no differences between groups were found. For sulcus depth, the 90-day value for the citric acid group was significantly increased over the preoperative level, but no other changes were noted. There appears to be no clinical justification for using citric acid conditioning as an adjunct to LPPF coverage of denuded roots.