In vitro tomographic image of human pulp-dentin complex: optical coherence tomography and histology.

INTRODUCTION: Optical coherence tomography (OCT), a noninvasive imaging method, was used in this work to image the pulp-dentin complex. Pulp and dentin are integrally connected in the sense that physiologic and pathologic reactions in one of the tissues will also affect the other. METHODS: An OCT system with 6-mum spatial resolution at 800 nm was used to image the pulp-dentin complex of in vitro samples. Five intact human maxillary premolars scheduled for surgical extraction were used in this in vitro study. The occlusal surfaces of teeth were polished with wet 600-, 1,000-, and 1,200-grit aluminum oxide abrasive paper perpendicular to the long axis of teeth, producing a plane on that surface. The images of pulp-dentin complex were taken by scanning the occlusal surface in a mesiodistal direction. The laser penetrated into the teeth structure and a tomographic image of pulp-dentin complex, parallel to the long axis of teeth, was obtained. Histological and OCT images were analyzed and compared. RESULTS: The results showed the capability of the OCT technique to generate images of the boundaries of pulp and its relation to the dentin. It could be clearly seen that the OCT image provided the insight into dentinal substrate about 0.65-mm deep (corrected for the dentin refractive index). CONCLUSION: OCT can be used in the future to prevent iatrogenic exposures of the pulp, complementing other existing methods, and will permit a more predictive prognosis of treatments.

Pulpotomy of human primary molars with MTA and Portland cement: a randomised controlled trial.

OBJECTIVE: This study compared the clinical and radiographic effectiveness of mineral trioxide aggregate (MTA) and Portland cement (PC) as pulp dressing agents in carious primary teeth. METHODOLOGY: Thirty carious primary mandibular molars of children aged 5-9 years old were randomly assigned to MTA or PC groups, and treated by a conventional pulpotomy technique. The teeth were restored with resin modified glass ionomer cement. Clinical and radiographic successes and failures were recorded at 6, 12, 18 and 24-month follow-up. RESULTS: All pulpotomised teeth were clinically and radiographically successful at all follow-up appointments. Six out of 15 teeth in the PC group and five out of 14 teeth in the MTA group exfoliated throughout the follow-up period. No statistically significant difference regarding dentine bridge formation was found between both groups throughout the follow-up period. As far as pulp canal obliteration is concerned, a statistically significant difference was detected at 6-month follow-up (p <0.05), since the beginning of mineralised material deposition could be radiographically detected in 100% and 57.14% of the teeth treated with PC and MTA, respectively. CONCLUSIONS: PC may serve as an effective and less expensive MTA substitute in primary molar pulpotomies. Further studies and longer follow-up assessments are needed.

Radiographic evaluation of pulpal and periapical response of dogs' teeth after pulpotomy and use of recombinant human bone morphogenetic protein-7 as a capping agent.

PURPOSE: The purpose of this study was to evaluate radiographically the pulpal and periapical response of dogs' teeth after pulpotomy and the use of recombinant human bone morphogenetic protein-7 (rHuBMP-7). METHODS: Pulpotomies were performed in 60 teeth of 6 dogs, and the remaining radicular pulp tissue was capped with the following materials: (a) groups 1 and 5-recombinant human bone morphogenetic protein-7 associated with recombinant human-like collagen; (b) groups 2 and 6-recombinant human-like collagen; (c) groups 3 and 7-calcium hydroxide; and (d) groups 4 and 8-zinc oxide and eugenol cement. After 7 days (groups 1-4) and 70 days (groups 5-8), standardized periapical radiographs were taken and the integrity of the lamina dura, presence of areas of periapical bone rarefaction, internal/external root resorption, and dentin bridge formation were evaluated. The results were analyzed statistically by Fisher's exact test and Bonferroni correction. The radiolucent areas suggestive of periapical lesions associated with the roots were measured in mm2, and the results were compared by Kruskal-Wallis test. RESULTS: In the 7-day period, all specimens in groups 1 to 4 presented intact lamina dura and absence of periapical bone rarefaction, internal/external root resorption or dentin bridge formation. In the 70-day period, no specimen in groups 5, 6, and 8 presented dentin bridge formation. Periapical bone rarefaction areas were observed to be associated with 100%, 60%, and 40% of the roots in group 6, 8, and 5, respectively. The largest lesions were found in group 6, followed by groups 5 and 8 (P<.05). In group 7, there was dentin bridge formation in 60% of the cases and intact lamina dura and no periapical bone rarefaction in all specimens. CONCLUSION: The use of rHuBMP-7/rHuCollagen as a capping material after pulpotomy did not induce mineralized tissue deposition, leading to the formation of radiographically visible periapical lesions.