Effects of an air-powder abrasive device used during periodontal flap surgery in dogs

Implant surface preparation in the surgical treatment of experimental peri-implantitis with autogenous bone graft and ePTFE membrane in cynomolgus monkeys

The aim of the present investigation was to assess the effect of four implant surface preparation methods used in the surgical treatment of experimental peri-implantitis with autogenous bone graft and expanded polytetrafluoroethylene (ePTFE) membrane. The methods were air-powder abrasive unit+citric acid, air-powder abrasive unit, gauze soaked in saline+citric acid, and gauze soaked alternately in chlorhexidine and saline. A total of 64 implants with a titanium plasma-sprayed (TPS) surface was placed in eight cynomolgus monkeys (Macaca fascicularis). After a 3-month period with plaque control, experimental peri-implantitis was induced. A bone loss of 4-6 mm was established after 9-17 months and plaque control was re-implemented. The peri-implantitis defects were surgically exposed, granulation tissue was removed, and each implant surface was prepared by one of the above-mentioned procedures. The defects were then filled with autogenous bone graft particles and covered by an ePTFE membrane. The animals were sacrificed after 6 months. Evaluation by clinical parameters, radiography including quantitative digital subtraction radiography, histology, and stereology did not reveal significant differences between the methods. Almost total bone regeneration and considerable re-osseointegration were obtained irrespective of the method applied. A mean bone-to-implant contact of 39-46% was observed within the defects. Therefore, the present study of implants with a TPS surface in cynomolgus monkeys indicates that the simplest method involving gauze soaked alternately in chlorhexidine and saline should be the preferred implant surface preparation method in the surgical treatment of peri-implantitis involving autogenous bone graft and ePTFE membrane.

The effectiveness of different root debridement modalities in open flap surgery

It is unclear what degree of roughness or smoothness result from use of hand instruments alone in comparison to the use of hand instruments in combination with other aids and how it may effect the grade of cleanliness. The aim of this study was to determine in vivo whether the combination of hand instruments with other aids can increase the effectiveness of root debridement. 11 patients with holpless 4 mandibular incisors were involved in this study. After elevating a lingual and buccal mucoperiosteal flap, the 4 incisors were randomly treated with either: (1) no treatment (control); (2) 5-min scaling (method 1); (3) 4-min scaling and 1 min instrumentation with a perio-diamond bur (15 microm) (method 2); (4) 3-min scaling, 1-min instrumentation with a perio-diamond bur (15 microm) and 1 min with an air abrasive system (method 3). The cleanliness of the surface was determined using the method of Eschler and -Rapley. The degree of roughness (Ra and Rt) were measured with a laser beam (computer supported optical surface sensor system). In addition, an SEM analysis was performed. With regard to the remaining calculus (surface cleanliness), method 3 yielded significantly better results than the other 2 methods. The roughness analyses also exhibited that method 3 is superior to methods 1 and 2. The qualitative results of the SEM investigations demonstrated the most homogeneous and smooth surfaces with method 3. Root debridement in vivo was most significant using a combination of different treatment modalities (i. e., curettes, perio-diamond bur and air abrasive system).

Report of the Committee on Scientific Investigation of the American Academy of Restorative Dentistry

Dental research continued to grow during 1988. Unfortunately the quality does not always parallel the quantity of publications. This report obviously does not encompass all of the literature but focuses on studies that are related to trends and to matters that are considered controversial. Likewise the particular interests of the members of the American Academy of Restorative Dentistry were taken into consideration. The subjects covered include periodontics, preventive dentistry, bulp biology, craniomandibular disorders, ceramics, color in restorative dentistry, and dental materials.