A sheep cadaver model for demonstration and training periodontal surgical methods

There is lack of data on the suitability of animal cadaver models for teaching purposes in dentistry. Here, we describe a model suitable for training for several periodontal surgical methods. Mandibles of freshly slaughtered Australian adult sheep and lambs were examined. Periodontal probing depths (PPDs) were measured at six sites of every tooth present. The following surgical techniques were critically analyzed: access flap with interrupted, continuous sutures; apically repositioned flap with periosteal sutures; coronally advanced flap with sling suture; gingivectomy; and distal wedge procedure. Probing depths were highest in the buccal furcation area of 1st and 2nd molars, where deep intrabony lesions were present in certain samples from adult sheep. Another area of increased probing depth was lingual to canines and incisors. Here, a pronounced lower dental pad of fibrous tissue was present. In this area, gingivectomy could always be accomplished. Fibrous tissue was also found distal to the most posterior molar, where the distal wedge procedure could be exercised. Access flaps and apically repositioned flaps could be performed particularly at premolars. Here, interrupted or continuous sutures were possible. Because of tight interdental contact areas, needle insertion was difficult at molars. After periosteal dissection, labial flaps at anterior teeth could easily be advanced coronally and sutured with sling sutures. Because of the teeth's dimensions and tight contact areas, simulation of more advanced techniques such as papilla preservation flaps was not possible. The sheep mandible seems to be a feasible training model for the demonstration and exercise of various periodontal surgical techniques for the treatment of periodontitis.     

Instruments for periodontal surgery. Indications for choice

The Authors, using their personal experience, discuss the necessary instruments for periodontal surgery (osseous and mucogingival), their quality and proper arrangement on the surgical table.     

Use of intracoronal splints in therapy of periodontal disease

The study concerns the evaluation of the efficacy of intracoronal composite splints (ICS) in the therapy of periodontal disease in its full clinical state. Maxillar and mandibular front teeth were splinted over the period of 12 weeks as a part of a complex therapy procedure of developed periodontal disease. The results of the therapy were evaluated using periodontal indexes, parameters for oral hygiene and other relevant clinical parameters. Values were processed with Student's t-test. With the use of ICS very good results in the therapy of periodontal disease in a short period of time were obtained. Parameter values decreased, especially the index of tooth mobility: before therapy by 2.84 and after therapy to 1.12. Intracoronal composite splints, in comparison with other type of splinting, satisfy both functional and aesthetic aspects.     

可摘式牙周夹板修复治疗牙周炎的临床效果分析

目的：评价可摘式牙周夹板对牙周炎伴牙列缺损患者的修复效果。方法：选取40例,随机分为2组,每组20例。两组患者行牙周基础治疗后,分别采用可摘式牙周夹板修复和可摘局部义齿修复,观察并记录不同时段各相关牙周指数。结果：可摘式牙周夹板组修复后24个月时菌斑指数（ plaque index,PLI）和出血指数（ bleeding in-dex,BI）较修复前增加（P＜0.05）;但修复后12个月和24个月时牙周探诊深度（periodontal probing depth,PD）较修复前下降,差异均有统计学意义（P＜0.05）。可摘局部义齿修复组修复后12个月和24个月时均出现PLI、BI和PD较修复前明显增加（P＜0.05）。结论：可摘式牙周夹板可改善牙周炎伴有牙列缺损患者的牙周状况,其修复疗效优于可摘局部义齿。     

Fixed cantilever splints on teeth with normal and reduced periodontal support

Photoelastic models were used to visualize stresses developed in teeth and supporting bone by cantilever fixed partial dentures where the most distal abutments had either crater or trough osseous defects. The effects of splinting the periodontally involved teeth to one or more additional sound teeth were studied. It was shown that for a cantilever fixed partial denture with either normal periodontal support, or a distal abutment with a moderate degree of mobility and bone loss, the following can be concluded: (1) occlusal forces on a cantilever fixed partial denture were significantly distributed to only the three teeth closest to the loaded cantilever, (2) optimum stress reduction occurred with the splinting of a periodontally compromised tooth to two periodontally sound teeth. Increasing the number of splinted abutments did not result in a proportional reduction of stress in the periodontium, and (3) no significant cross-arch sharing of occlusal loads was seen.     

Strength determination of periodontal splints fabricated from acid-etched retained materials.

Six systems (one polycarboxylate, one polymethyl methacrylate, one unfilled BIS-GMA resin, two combinations of methyl cyanoacrylate and polymethyl methacrylate, and one combination of unfilled BIS-GMA and filled composite resin) were evaluated for in vitro retention to acid-etched human enamel. Also tested were one unfilled-filled resin combination backed by perforated orthodontic band metal and another unfilled resin backed by stainless steel wire mesh. Significant differences in retention were found. Results show that retention depends pril surface and to resist subsequent chemical degradation.