摘要:

The purpose of this study was to compare the effect of plaque accumulation in conjunction with or without placement of plaque‐retaining ligatures on peri‐implant and periodontal tissues. Four cynomolgus monkeys received 2 ITI (Type F) dental implants in edentulous areas of each side of the mandible. Following a healing period of 2 months with regular prophylaxis procedures twice per week, plaque was allowed to accumulate. After 1 month (day 0), silk ligatures were placed around 1 of the 2 implants. The third molars served as controls and were ligated as well. Clinical examinations comprising Plaque Index (PlI), Gingival Index (GI), probing depth (PD) and loss of attachment (LA) were performed at the test and control sites before and 1, 2, 3, 4, 5, 6, 7 and 8 months after ligature placement. Sixty and 30 days prior to ligation and at 2, 5, 6 and 8 months following ligation, standardized radiographs were obtained and subtracted from a baseline radiograph obtained at the time of ligation. PI1 and GI scores increased significantly following the elimination of prophylaxis procedures. After ligation, these indices continued to increase and reached values significantly higher in ligated implant (LI) and ligated teeth (LT) sites than in non‐ligated teeth (NLI) sites. PD also increased after plaque accumulation and ligature placement. Significantly greater PD values were noted in LI and LT sites than in NLI sites. Also, loss of attachment was observed already after 1 month following ligation in LI and LT sites and reached a value of 3.8 mm after 8 months, whereas only 1.0 mm of attachment was lost after 7 months of plaque accumulation in NLI. Similar results were noted in the analysis of the subtraction images. LI and LT sites lost significantly more bone density and more alveolar bone height, but the NLI sites yielded relatively stable conditions throughout the study. It is concluded that the development of a peri‐implant infection progressed at a similar rate as the development of a periodontitis lesion and that ligature placement significantly promoted the development of these lesions when compared with the development of an inflammatory response in the peri‐implant tissues as a result of bacterial plaque acc

ISSN:0905-7161    

DOI:10.1034/j.1600-0501.1993.040101.x

出版商:Munksgaard International Publishers    

年代:1993

数据来源: WILEY

摘要:

The purpose of the investigation was to gain more understanding of marginal inflammatory reactions around osseointegrated implants. The significance of the lacking periodontal ligament of implants was examined in the initial breakdown phase of supporting tissues by comparing clinical and radiographic manifestations of ligature‐induced marginal inflammation related to osseointegrated implants with those around ankylosed and normal control teeth in 8 cynomolgus monkeys (Macaca fascicularis). Bilateral extraction of the first and second mandibular molars was carried out initially, and 12 weeks later 2 implants were placed in each side. Ankylosis of the second maxillary molars was established by extracting and replanting the teeth after a drying period. When ankylosis and osseointegration were established, ligature‐induced marginal inflammation was induced in the right or left side at random around implants, ankylosed teeth and normal control teeth (second maxillary premolar) for 7 weeks. Although the clinical manifestations as expressed by plaque score, gingival score, probing depth and attachment loss were quite similar, the radiographic features differed. Significant loss of bone height was limited to implants and ankylosed teeth and did not occur in relation to normal control teeth. Furthermore, the bone loss around implants was significantly greater than the loss around ankylosed teeth. Bone loss was limited to implants and ankylosed teeth; the study therefore suggests that the presence of marginal inflammation around implants and ankylosed teeth may have more serious implications than does marginal inflammation around teeth with a periodontal ligament. However, variations in microbiota and susceptibility of different jaw positions to periodontal breakdown may influence the results of this st

ISSN:0905-7161    

DOI:10.1034/j.1600-0501.1993.040102.x

出版商:Munksgaard International Publishers    

年代:1993

数据来源: WILEY

摘要:

In order to test the soft tissue response to contaminated titanium components, 20 clinically retrieved abutment cylinders were inserted in the abdominal wall of 5 rats. Prior to insertion, 10 of the abutments had been contaminated for 1 min and the remaining components for 2 weeks. Five abutments of either group were ultrasonically cleaned in butanol and ethanol, whereas the remaining abutments were only rinsed in saline before being implanted. As controls, 5 newly manufactured abutments were used. After 6 weeks of healing, specimens were prepared of the components and surrounding tissues for morphological analysis. This showed an accumulation of macrophages and a reduction of the number of fibroblasts around the abutments that had been contaminated, irrespective of cleaning procedure, compared with the controls. It was concluded that the contaminated components induced an altered tissue response and that a similar reaction may occur in the clinical situation.

ISSN:0905-7161    

DOI:10.1034/j.1600-0501.1993.040103.x

出版商:Munksgaard International Publishers    

年代:1993

数据来源: WILEY

摘要:

Radiofrequent magnetron sputtering was used to produce calcium phosphate coatings on metal and plastic substrates. Scanning electron microscopy showed that the deposited films had a uniform thickness and a dense columnar structure. Energy‐dispersive X‐ray analysis, X‐ray crystal diffraction and atomic absorption spectrometry demonstrated that the sputtered layer was well‐crystallized calcium phosphate ceramic with a Ca/P ratio varying between 1.9 and 2.5. The biocompatibility of the coatings was determined by in vitro and in vivo experiments. It was found that the coatings were biocompatible without any sign of adverse tissue reaction. It was concluded that magnetron sputtering is a promising method for forming a biocompatible ceramic coating onto an implant material. Nevertheless, several problems have to be solved before magnetron sputtering can be used on a routine basis for the production of Ca/P c

ISSN:0905-7161    

DOI:10.1034/j.1600-0501.1993.040104.x

出版商:Munksgaard International Publishers    

年代:1993

数据来源: WILEY

摘要:

In guided tissue regeneration (GTR) procedures, flap recession or sloughing may occur as an unwanted sequel to the placement of a membrane. This study was designed to assess the applicability of laser Doppler flowmetry (LDF) in the evaluation of blood perfusion in the mucoperiosteal flap covering the membrane. Five Labrador dogs were initially used inthe study, but one animal was later excluded due to post‐operative problems. Maxillary premolar teeth were extracted and full thickness mucoperiosteal flaps were raised. Following removal of the buccal bone plate, 4 titanium implants were placed on each side. An experimental biodegradable polylactic‐acid membrane was placed over the fixtures on one side to allow for GTR. The mucoperiosteal flap was repositioned and secured with sutures. The contralateral side served as control with no membrane. Blood perfusion was measured in the flaps before surgery, immediately after suturing and at 24, 48 and 72 h postoperatively. A laser Doppler flowmeter was used to assess the blood perfusion. In 3 animals the membrane was exposed within 2 weeks post‐operatively, and in these 3 animals the LDF values were lower on the membrane side than on the control side. The mean LDF value was lower on the membrane side for each of the 4 periods studied. The tindings suggest that LDF can be a valuable method to study blood perfusion of oral mucosal flaps and that there may be a relationship between a reduced relative LDF value and subsequent exposure of the membrane to the oral enviro

ISSN:0905-7161    

DOI:10.1034/j.1600-0501.1993.040105.x

出版商:Munksgaard International Publishers    

年代:1993

数据来源: WILEY

摘要:

In order to satisfy the need to restore the aesthetics, phonetics and comfort and to facilitate optimal hygiene procedures, 20 edentulous patients were treated with a new concept of overdenture therapy on implants ad modum Brånemark. After 24±3.5 months the patients were re‐examined. They were asked to answer a questionnaire and use a Visual Analogue Scale (VAS) to give their opinion on the prosthetic treatment. The results indicate that an implant‐retained overdenture in the maxilla with this design can satisfy the patients needs in aesthetics, phonetics and comfort and can 1 facilitate oral hygiene mea

ISSN:0905-7161    

DOI:10.1034/j.1600-0501.1993.040106.x

出版商:Munksgaard International Publishers    

年代:1993

数据来源: WILEY

摘要:

Satisfactory functional and aesthetic rehabilitation of a patient after total bilateral maxillectomy is a great challenge to the surgeon and prosthodontist. A particular problem is support and retention of the obturator. In the case described, the problem was solved by attaching the prosthesis with finger clasps to a classic AO‐reconstruction plate anchored rigidly with screws to both zygomata. The results in terms of mastication, swallowing, phonation and aesthetics were satisfactory for more than 2 years, when the patient died from brain metastasis and pneumonia. The technique seems promising and merits further study using titanium screws and plate

ISSN:0905-7161    

DOI:10.1034/j.1600-0501.1993.040107.x

出版商:Munksgaard International Publishers    

年代:1993

数据来源: WILEY