Effect of soaking in Hank's balanced salt solution or milk on PDL cell viability of dry stored human teeth

Abstract— This study was designed to evaluate the effect of soaking in either Hank's balanced salt solution (HBSS) or milk on peri⁻odontal ligament (PDL) cell viability in avulsed teeth. Dry storage times of 30, 60, and 90 min were evaluated. PDL cell viability was determined after removal of the cells from the root surfaces of extracted teeth using a modification of the procedure described by Nakashima (Arch Oral Biol 1991;36:655–63). After trypsinization and subsequent treatment in collagenase, the cells were stained with trypan blue, and viable and non-viable cells were counted using a hemocytometer and converted to percentages for statistical comparison. The results of this study demonstrated no significant difference in the number of viable cells with or without soaking in HBSS or milk at any of the dry storage times. In addition, there was no significant difference in PDL cell viability between the 30-and the 60-min dry periods. Although the soaking procedure had no obvious negative consequence, no simcant improvement in PDL cell viability by the addition of this step was demonstrated under the conditions of this study.     

Periodontal healing of exarticulated monkey teeth stored in milk or saliva

Abstract – Saliva has usually been recommended as a storage medium for exarticulated teeth. Recent tissue culture studies have, however, shown that milk has a more suitable osmolaliry than saliva and that milk is a bettter storage medium for human periodontal ligament cell. In the present investigation periodontal healing of replanted monkey teeth has been studied after storage of teeth in milk or saliva before replantation. There was much less root resorption, especially inflammatory resorption, after storage in milk thatn in saliva. Storage of teeth in milk for 3 h before replantation resulted in the same low frequence of root resorptions as was seen after immediate replantation. There was hardly any replacement resorption (ankylosis) seen in the replanted teeth.     

Vitality of periodontal ligament cells after storage of monkey teeth in milk or saliva

Vitality of die periodontal ligament (PDL) is necessary for a successful healing after replantation of exarticulated teeth. In the present investigation newly extracted teeth from monkeys were stored in saline, milk or saliva for 1–3 h. Freeze sections were made and the vitality of the PDL was determined histochemically. Milk seemed to provide better storage conditions than saliva or saline.     

全脱位牙牙周膜细胞活性在牛奶中的保存及其影响因素

全脱位牙回植可在外伤后短时间内重建咬合功能,恢复患者的容貌.牙回植成功与否关键在于保存患牙牙周膜细胞的活性,而保存时间和保存介质在其中起着十分重要的作用.牛奶廉价易得,可及时获取,有利于全脱位牙牙周膜细胞活性的及时保存,但不同种类、成分和温度的牛奶,其保存牙周膜细胞活性的能力和有效保存时间也不尽相同.此外,牛奶作为一种短期的全脱位牙牙周膜细胞活性保存介质,定期更新牛奶并没有太大的临床意义.保存在牛奶中的全脱位牙回植前需在汉克平衡盐溶液中浸泡30 min,以补充牙周膜细胞所需的营养物质,提高其增殖分化能力.     

Tritiated thymidine uptake in periodontal ligament cells of dogs' teeth stored in various media for extended time periods

Abstract The purpose of this study was to evaluate a new storage solution, Conditioned Medium, vs Hank's balanced salt solution and ViaSpan with respect to the viability of periodontal ligament cells of exarticulated teeth. Teeth were stored for periods of 6, 48, and 96 hours in Hank's balanced salt solution, ViaSpan (Dupont Pharmaceuticals), or Conditioned Medium. Teeth were cultured for 24 hours in Dulbecco's medium supplemented with tritiated thymidine. The cultured teeth were sectioned and evaluated with autoradiography. Control teeth were extracted and immediately treated as above without storage. Mitotic activity was indicated by clusters of five or more grains over the nuclei of fibroblasts in the remaining periodontal membrane. The ratio of labeled to unlabeled cells (labeling index) was calculated for each treatment group. When storage time was compared across all groups, 96 hours was significantly different from 6 and 48 hours (P<0.001 and P<0.012 respectively). Storage time of 6 hours was not significantly different from 48 hours (P>0.10). After comparison of the nine experimental groups with the control group, only Hank's balanced salt solution at 96 hours was significantly different (P>0.004).     

Survival of human periodontal ligament cells in media proposed for transport of avulsed teeth

Abstract –  Many solutions have been examined as possible storage media for avulsed teeth. In this report, human periodontal ligament (PDL) cells were exposed for 1 h to culture medium, milk, Hanks Balanced Salt Solution (HBSS), Soft Wear, Opti Free, and Solo Care contact lens solutions, Gatorade^®, and tap water, at room temperature and on ice. The number of viable cells was counted using the trypan blue exclusion technique, immediately after exposure (0 h) and at 24 and 48 h, to test the proliferative capacity of the cells after treatment. The results indicated that a significantly higher number of cells survived and proliferated when the exposures were performed at 0°C. Water had a detrimental effect on the cells, whereas culture medium and HBSS preserved significantly more viable cells than the other experimental solutions. Within the parameters of this study, it appears that HBSS is the optimal storage medium for avulsed teeth. Low-fat milk could serve as an alternative if ice is available. Contact lens solutions or Gatorade^® on ice could serve as short-term (1 h) storage media if the other solutions are not readily available.     

Vascular reactions in the periodontal ligament incident to trauma from occlusion

Abstract The experiments were performed in 13 dogs; nine of the animals had initially a healthy periodontium and four had experimental periodontitis. Trauma from occlusion was created in all dogs according to a technique described previously. The dogs were sacrificed after 7, 14, 30 and 180 days of the experiment. Prior to sacrifice colloidal carbon was injected intravenously. The degree of vascular labelling and leucocyte infiltration as well as osteoclastic activity and the size of the marginal periodontal ligament were assessed in biopsy sections. The findings showed that dogs with a healthy periodontal lesion (Group A) differed in their reactions to a jiggling type of occlusal trauma when compared to dogs with an established periodontal lesion (Group B). Whereas the periodontal ligament in Group A had become adapted to the altered occlusion by the end of 6 months of experiment, that of Group B still showed increased vascular leakage, leucocyte migration and osteoclastic activity.     

Viability of human periodontal ligament cells after storage in milk or saliva

The prognosis of replantation of traumatically exarticulated teeth is very much influenced by the conditions under which the teeth have been kept before replantation. Saliva has been recommended as the most suitable storage medium but there are no studies where saliva has been compared with other possible storage media. Milk is such an easily available storage medium. The purpose of the present investigation was to compare the storage effect of milk with that of saliva on human periodontal ligament cells. Milk was superior to saliva as storage medium with respect to number of viable cells, cell size, ability to recover and to heal experimentally produced wounds. The osmolality of milk seems to be the most important factor.     

咬合创伤下大鼠磨牙牙周膜中转化生长因子β1表达的变化

目的：了解咬合创伤下转化生长因子β1(transforming growth factorβ1 TGFβ1)在大鼠磨牙牙周膜中表达的变化，探讨咬合创伤下TGFβ1在牙周组织改建中的作用。方法：建立咬合创伤动物模型，利用HE染色法和免疫组织化学技术，观察大鼠磨牙在咬合创伤后12小时、3天、7天、14天、30天的不同时期内牙周膜中TGFβ1表达的变化，并运用图像分析技术将结果数值化。结果：咬合创伤下，牙周膜中TGFβ1的表达在12小时组、3天组与正常咬合力组相比无显著差异；7天组、14天组与正常咬合力组相比有显著差异，并高于后者；30天组与正常咬合力组相比无显著差异。结论：TGFβ1可能在咬合创伤下牙周组织的改建中起了重要的作用。     

Reinnervation in the canine periodontal ligament of replanted teeth using an antibody to protein gene product 9.5: an immunohistochemical study

Abstract— The re-innervation process in the periodontal ligament of replanted canine teeth was examined by immunohistochemistry for protein gene product 9.5 (PGP 9.5), a general marker for neurons, and by electron microscopy. Within 1 week of replantation, the periodontal fibers had regenerated, filling the narrow spaces between the alveolar bone and the root surface around the cervical and apical regions. Near the root apex, however, no PGP 9.5-im-munopositive nerve fibers were found in the regenerated periodontal ligament except for those in the alveolar half of the ligament. At 2 weeks after replantation, many nerve fibers positive for PGP 9.5 had ascended the periodontal ligament from the thick nerve bundles located near the root apex. Fine nerve endings showing complicated ramification were also present in the apical region. By 3 or 4 weeks after replantation, the vascular network was regenerated and principal periodontal fibers were re-established throughout the entire length of the periodontal ligament. The extensively ramified PGP 9.5-immunopositive structures had increased in thickness and density and showed characteristic treelike profiles by 3 weeks. Electron microscopy confirmed that most of these structures were Ruffini-like endings, and demonstrated that such nerve terminals were almost regenerated by 4 weeks post-replantation. These results indicated that, in the periodontal ligament of replanted canine teeth, the regeneration of the nerve fibers including mechanosensory receptors first showed signs of regeneration by 2 weeks following tooth replantation and proceeded rapidly thereafter. Regeneration of the periodontal ligament including fiber architecture as well as vascular and neural elements was almost complete by 4 weeks after replantation.