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Biomedical subjects

A C Wetzel

Publications and source records attributed to A C Wetzel.

7 recordsLinked to original sources
PubMed1999

Attempts to obtain re-osseointegration following experimental peri-implantitis in dogs.

The purpose of this study was to examine the healing potential and re-osseointegration in peri-implant infection defects adjacent to various implant surfaces. In 7 female Beagle dogs, a total of 41 titanium oral implants (ITI, Straumann, Waldenburg; Switzerland) with a sink depth of 6 mm (diameter 2.8 mm) were placed transmucosally. Four different surface configurations (TPS: titanium plasma sprayed (10); SLA: sand blasted and acid-etched (13); M: machined and smooth (11); TPS furc.: titanium plasma sprayed with coronally placed perforation to mimic a furcation (7) were distributed among the animals and locations. Following a healing period of 3 months, silk ligatures were placed and oral cleaning procedures abolished for 4 months to induce a vertical bone loss of about 40%. Following mechanical and chemical cleansing (chlorhexidine and metronidazole) and disinfection, the lesions were either sham operated (11) or subjected to a GTR procedure using ePTFE (30). After 6 months of healing the animals were killed and the jaws histologically evaluated. Six membranes were lost TPS: (1); SLA: (2); M: (2); TPS furc: (1) and 3 membranes exposed TPS: (1); M: (2) and excluded from further evaluation. Owing to the loss of 1 implant and infection of the membranes in the TPS furc group, this implant configuration was discarded from further analysis. For TPS surfaces, bone fill was 2.6 mm (73% of the distance from the bottom of the defect to the shoulder of the implant) sites with (4 GTR) and 0.33 mm (14%) for sites without membrane (2 controls). Re-osseointegration was 0.5 mm (14%) in the test group and 0.3 mm (14%) in the control. For SLA surfaces bone fill was 2.3 mm (83%) for sites with (7 GTR) and 0.41 mm (15%) for sites without membranes (4 controls). Re-osseointegration was 0.6 mm (20%) and 0.3 mm (11%) respectively. Corresponding values for M surfaces were 2.2 mm (62%) with 4 GTR) and 0.82 mm (31%) without membranes. Re-osseointegration was 0.07 mm (2%) and 0.19 mm (7%) respectively. This study has documented that peri-implant infections defects may heal with bone fill provided that the infection is controlled through effective antibacterial therapy. However, true reosseointegration appears to be difficult to achieve.

Alveolar Process↗
PubMed1995

Bone apposition onto oral implants in the sinus area filled with different grafting materials. A histological study in beagle dogs.

The placement of oral implants into jaw bone has a high predictability provided an adequate bone volume surrounding the implant is present to ensure primary stability and resistance to functional loading forces after completion of osseointegration. In the distal area of the maxilla, an adequate bone volume is often lacking because of the proximity of the sinus cavities. The aim of this study was to evaluate histologically the simultaneous placement of endosseous implants into the sinus cavity and the surgical elevation of the sinus floor including filling the cavity with different grafting materials. In 9 sinus areas of 5 beagle dogs, 9 titanium implants (ITI Dental Implant System) were placed, and the void space of the sinus cavity was filled simultaneously with either demineralized freeze-dried human cortical bone (Musculoskeletal Transplant Foundation), resorbable hydroxyapatite (Osteogen) or natural cancelleous bovine bone mineral (Bio-Oss). To study bone formation, fluorochrome markers (tetracycline HCl and calcein green) were used at 2 and 8 weeks. Clinically, all implants healed uneventfully, and 5 months after implant placement the dogs were killed for histologic evaluation. All implants exhibited osseointegration within the pre-existing cortical bone of the sinus floor. The implants surrounded by freeze-dried bone xenografts yielded no formation of new bone, whereas the sites with hydroxyapatite or natural bovine bone mineral demonstrated newly formed bone with direct contact at the implant surface. The average extent of bone to implant contact was 25% (SD = 10.6%) and 27% (SD = 8.8%), respectively in relation to the length of the originally denuded implant surface.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

Histologic probe penetration in healthy and inflamed peri-implant tissues.

Periodontal probing is commonly used for assessing both the status of gingival health and the connective tissue attachment level around teeth. The role of probing around endosseous implants still remains unclear. The purpose of this study was to determine the histological level of probe penetration in healthy and inflamed mucosal tissues around implants. Five beagle dogs were used and a total of 30 one-stage, Titanium Plasma Spary (TPS)-coated implants of the ITI type were placed in the mandibles. After the healing period with meticulous oral hygiene, the dogs were divided into 3 groups: 1) clinical healthy mucosal tissues; 2) experimental mucositis (3 dogs); and 3) experimental ligature-induced peri-implantitis (2 dogs). Four months after implant placement, respectively 6 months in the third group, 60 probes were placed with a standardized force of 0.2 N and fixed at the mesial and distal aspects of the implants. Probing depth, clinical attachment level (CAL), Plaque Index (PlI) and Gingival Index (GI) were assessed throughout the study. Tissue sections were obtained for histometrical analysis. In the healthy group, the mean PII was 0.47, the GI 0.06 and the clinical probing depth (CPD) 2.12 mm. In the mucositis group the PlI was 1.61, the GI 1.61 and the CPD 1.87 mm. In the peri-implantitis group the PlI was 1.96, the GI 2.05 and the CPD 3.73 mm. The histologic results show that the probes were able to identify the connective tissue adhesion level in the healthy group with a mean error of -0.05 mm (mean histologic probing depth (HPD): 1.75 mm) and, in the mucositis group, with -0.02 mm (mean HPD: 1.62 mm). Probe penetration increased with the degree of inflammation and in the peri-implantitis group the probe exceeded the connective tissue level by a mean 0.52 mm (mean HPD: 3.8 mm). Therefore, probing around implants represents a good technique for assessing the status of peri-implant mucosal health or disease.

Animals↗
PubMed1993

Guided bone regeneration at a fenestrated dental implant: histologic assessment of a case report.

Guided tissue regeneration has been shown to establish new attachment in periodontal defects and to facilitate hard tissue repair around dental implants. This case report describes a patient treated with guided tissue regeneration adjacent to an endosseous dental implant. Histologic analysis showed the regenerated tissue to be mature, cortical bone possessing a high level of mineralization.

Alveolar Bone Loss↗
PubMed1992

Application of BANA during experimental gingivitis. Application of N-alpha-benzoyl-DL-arginine 2 naphtilamide (BANA) hydrolysis to identify periodontopathic environments during experimental gingivitis in man.

This study evaluates the accuracy of the PerioScan reagent card kit which uses BANA hydrolization to detect the presence of P. gingivalis, T. denticola, and B. forsythus in dental plaque during an experimental gingivitis in man. 32 healthy subjects underwent a phase of optimal oral hygiene before they abolished all oral hygiene practices for 21 days, but rinsed twice daily with a slurry of three different toothpastes. On days 0, 7, 14, and 21, full mouth Plaque and Gingival Index scores were assessed and, in addition, on days 0 and 21, sulcular plaque samples were obtained from the mesiobuccal aspects of the second premolars. The samples were placed on BANA reagent cards (PerioScan), and the result of the trypsin-like activity read after 15 minutes. Subsequently, the samples were processed for the detection of P. gingivalis, T. denticola and B. forsythus using ELISA. The Gingival Indices on day 21 indicated a development towards gingival inflammation. The frequencies of detection of the three periodontopathogens revealed by ELISA showed increased presence of P. gingivalis, B. forsythus and T. denticola on day 21. Changes in the composition of the microbiota were also indicated by the higher rate of positive BANA results at the end of the experimental gingivitis. Without considering further clinical diagnostic tests such as "bleeding on probing", this clinically simple test does not provide a prognostic indicator for the eventual onset of disease in cases with gingival inflammation. However, specificity was only 61% and the sensitivity was 41.7%.

Adult↗
PubMed1991

Use of BANA hydrolysis as a diagnostic test for identifying periodontopathic environments.

The purpose of the present study was to evaluate the diagnostic value of the BANA hydrolysis test using the Perio Scan kit to identify subgingival periodontopathogens (P. gingivalis, T. denticola and B. forsythus) and to determine whether the BANA reaction reflected the presence or absence of clinical signs for periodontitis. 10 patients with periodontitis (AP), 10 healthy subjects (HS) and 10 subjects with treated periodontitis under supportive therapy (MP) participated in the study. Subgingival plaque was sampled and the presence or absence of the above mentioned bacteria assessed with BANA reagent cards (Perio Scan). Additionally, all samples were analyzed for the presence or absence of P. gingivalis and/or T. denticola using an ELISA. The BANA test yielded a high specificity (86.7%) and a high sensitivity (77.0%) for the presence of periodontopathogens when compared with the ELISA results as reference parameter. The diagnostic features of the BANA test result compared to the clinical parameters yielded a high degree of accuracy for overall clinical judgement and for probing depth (PD 5 mm), but to a lesser degree, for bleeding on probing.

Adult↗