Kim S, Dörscher-Kim J E, Liu M, Grayson A
Laboratory of Oral Physiology, Columbia University, School of Dental and Oral Surgery, New York.
Proc Finn Dent Soc. 1992;88 Suppl 1:65-71.
Using the quantitative 15 microns microsphere injection method, the effects of several restorative procedures on pulpal microcirculation in dog canine teeth were investigated. Pulpal blood flow (PBF) decreased steadily as the remaining dentin thickness (RD) became smaller with crown preparation without water spray. One hour after the preparation wit 1/3 RD (approximately 1 mm) PBF was reduced to 10% of the control, indicating that dry deep preparation has a deleterious effect on PBF. A careful preparation to an RD of 1 mm under copious water spray had a negligible effect on PBF. Dry preparation to an RD of more than 50%, on the other hand, caused a significant increase in blood flow through shunt vessels, AVAs and "U"-turn loops as determined with the 9 microns and 15 microns microspheres. These shunt vessel activities were especially prominent in the apical portion of the pulp, suggesting that the activation of the shunt vessels may be one of the compensatory mechanisms of the pulp in response to inflammation. In rat incisor teeth observed by intravital microscope, shunt vessels opened up as the incisor tips were drilled. Impression procedures after tooth preparation with water spray using the copper band with wax caused severe flow fluctuation as compared to rubber base material impression. In anesthetics, the use of epinephrine was found to be the single most important factor affecting pulp circulation. Whether it is by infiltration or mandibular block, the use of epinephrine containing anesthetic caused a severe reduction in PBF.(ABSTRACT TRUNCATED AT 250 WORDS)
采用定量15微米微球注射法，研究了几种修复操作对犬科动物犬齿牙髓微循环的影响。在无水喷雾的情况下进行牙冠预备时，随着剩余牙本质厚度（RD）变小，牙髓血流量（PBF）稳步下降。在制备至1/3 RD（约1毫米）后1小时，PBF降至对照的10%，这表明干法深度制备对PBF有有害影响。在大量水喷雾下小心制备至1毫米的RD对PBF的影响可忽略不计。另一方面，干法制备至超过50%的RD，会导致通过分流血管、动静脉吻合支（AVAs）和“U”形转弯环的血流量显著增加，这是用9微米和15微米微球测定的。这些分流血管活动在牙髓根尖部分尤为突出，表明分流血管的激活可能是牙髓对炎症反应的代偿机制之一。在通过活体显微镜观察的大鼠切牙中，当切牙尖端钻孔时，分流血管会开放。与橡胶基材料印模相比，使用带蜡铜带在有水喷雾的情况下进行牙体预备后的印模操作会导致严重的血流波动。在麻醉剂方面，发现使用肾上腺素是影响牙髓循环的最重要单一因素。无论是通过浸润麻醉还是下颌阻滞麻醉，使用含肾上腺素的麻醉剂都会导致PBF严重降低。（摘要截断于250字）
