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Biomedical subjects

M Petelin

Publications and source records attributed to M Petelin.

7 recordsLinked to original sources
PubMed2000

Local delivery of liposome-encapsulated superoxide dismutase and catalase suppress periodontal inflammation in beagles.

BACKGROUND, AIMS: The purpose of this study was to evaluate the influence of oxygen free radical scavengers on periodontal inflammation and healing process. METHOD: Experimental periodontitis was induced by elastic ligatures around premolars (P2, P3, P4) and 1st molars (M1) in the upper and lower jaws of 15 beagle dogs. 9 months after the beginning of the experiment, the ligatures were removed. After 3 weeks of stabilization period, all teeth were supragingivally scaled. The animals were divided into 3 groups of 5 dogs. The 1st group received a liposome-encapsulated superoxide dismutase (SOD), the 2nd group a liposome-encapsulated catalase (CAT) and the 3rd group received both enzymes encapsulated in liposomes. 4 treatment modalities were tested in each group; i.e., supragingival scaling only (1), supragingival scaling and enzymes (2), supra- and sub-gingival scaling and root planing (3) and supra- and sub-gingival scaling and root planing with subgingival application of enzymes (4). Enzymes were delivered subgingivally on a daily basis for a period of 6 weeks. Gingival index (GI), probing depth (PD), clinical attachment level (CAL), radiographic analysis and the histological evaluation were performed. RESULTS: Around the teeth with scaling and root planing followed by the application of SOD, the greatest suppression of gingival inflammation (GI = 1.8 +/- 0.1 before versus GI = 1.2 +/- 0.2 after treatment) (p<0.003), the smallest size of connective tissue infiltrate (5.5 +/- 4.3%) (p<0.01), the greatest reduction of PD (PD= 3.2 +/- 1.0 mm before versus 2.00.7 mm after treatment) (p<0.001), and gain of CAL (CAL=3.0 +/- 1.7 mm before versus CAL=2.4 +/- 1.1 mm after treatment) (p<0.001) were observed. In addition, radiographic analysis showed the greatest alveolar bone apposition in the group of teeth treated with scaling and root planing followed by subgingival application of SOD or both enzymes (p<0.001). CONCLUSION: In conclusion, we demonstrated that scaling and root planing with subgingival application of liposome-encapsulated SOD suppress peridontal inflammation on experimentally induced periodontitis in beagle dogs.

Alveolar Bone Loss↗
PubMed1999

The permeability of human cementum in vitro measured by electron paramagnetic resonance.

The structure and permeability of cementum are changed during the course of periodontal disease. In this study, the transport of water-soluble, spin-labelled molecules through cementum was studied by electron paramagnetic resonance (EPR). Cementum samples cut from different parts of the root were classified into four different groups: (A) samples exposed to the oral environment, (B) samples exposed to the periodontal-pocket environment; (C) samples cut from periodontally involved teeth but not exposed to saliva or periodontal pocket and (D) samples from sound young teeth extracted for orthodontic reasons. In order to obtain undamaged cementum, a dentine layer was left on each sample. Two methods were used to measure the diffusion coefficients of spin-labelled molecules in cementum dentine samples. First, the method of one-dimensional EPR imaging (EPRI) was used to evaluate the penetration of spin-labelled molecules into the cementum/dentine structure. Second, the diaphragm-cell method was used to determine the diffusion coefficients of the labelled molecules through the cementum under steady-state conditions. The results indicate that the interface between cementum and dentine is a barrier to diffusion. A set of diffusion (D) and partition (K) coefficients to describe the molecular transport in cementum, barrier and dentine was generated from the experimental data of both methods. For cementum (c), the barrier (b) and dentine (d) these coefficients were: Dc= 10(-8)cm2/s, Db= 10(-10)cm2/s, Dd= 10(-6)cm2/s and K=0.1. For the particular periodontally involved and uninvolved teeth the value of the rate-limiting barrier was DbA= 0.3 +/- 0.03 x 10(-10)cm2/s, DbB= 1 +/-0.3 x 10(-10)cm2/s, DbC= 0.3 +/- 0.03 x 10(-10)cm2/s, DbD= 0.4 +/- 0.05 x 10(-10)cm2/s. The largest diffusion flux across the dental hard tissue was found in the samples that had been exposed to the pocket environment (3.1 +/- 0.2) x 10(-9)cm2/s (p < 0.01), which coincided with the permeability calculated from the data evaluated by EPRI. The transport of the labelled molecules into and through the cementum dentine samples depends on the structure of the dental hard tissues, which changes during the course of periodontal disease. Knowledge of molecular diffusion across the tooth cementum/dentine structure is likely to be important for planning new treatments for periodontal disease.

Adolescent↗
PubMed1997

Changes in TGF-beta 1 levels in gingiva, crevicular fluid and serum associated with periodontal inflammation in humans and dogs.

Transforming growth factor-beta (TGF-beta) represents a family of polypeptide growth factors, involved in embryogenesis, inflammation, regulation of immune responses and wound healing. To determine whether TGF-beta contributes to the evolution of periodontal disease, we assayed TGF-beta levels in gingiva and crevicular fluid of patients with gingivitis and periodontitis. In parallel, TGF-beta was quantified in gingival fluid and serum of beagles with experimentally-induced periodontitis. Disease was monitored by several clinical parameters including Plaque Index, Gingival Index, probing depth, and epithelial attachment loss. Gingival tissues were obtained from 9 patients at the time of periodontal surgery, and gingival fluid samples were collected from an additional population of 10 periodontal patients. In 14 beagles, experimental periodontitis was induced and gingival fluids collected 6 months later. Fluid was collected by paper strips and volume measured by Periotron. Additionally, sera was collected before and 9 months after the ligature-induced periodontitis in 7 beagles. The levels of TGF-beta 1 were measured by ELISA. In the patients, a significantly higher concentration of TGF-beta 1 was observed both in the gingival tissues and fluid samples obtained from the sites with deeper periodontal pockets than in the less involved sites. In beagles, TGF-beta 1 levels measured in gingival fluid were elevated in moderate disease, declining in fluid samples obtained from the pockets during more advanced experimental periodontitis. Furthermore, with the progression of experimental periodontitis, a decrease in TGF-beta 1 occurred in the sera of the beagle dogs. These data suggest that TGF-beta 1 may play a rôle in the pathogenesis and diagnosis of periodontal disease, and that its actions can be further explored in an animal model.

Adult↗
PubMed1997

Diagnostic systems for assessing alveolar bone loss.

Radiological diagnostics serves as a basic monitoring technique for alveolar bone loss which is a severe consequence of periodontal disease. To evaluate efficacy of Conventional Visual Radiography (CVR), and to assess a complete clinical status, we had used two more diagnostic systems. These are Digital Subtraction Radiography (DSR) and Probing Pocket Depth (PPD). Experimental Periodontitis was studied in 20 beagle dogs based on the measurements taken in the beginning (baseline), and before (11th month) and after the medical treatment (12th month). Data analyses pointed out the same clinical trend, i.e. a significant bone loss prior to medical treatment and its recovery to the initial state. Differences in metrics and measurement errors could be identified as causes for discrepancies between the systems, but a relationship between the CVR and PPD is worth of further research, as these systems do not appear to be entirely compatible, but rather complementary to each other.

Alveolar Bone Loss↗
PubMed1991

Postnucleation orbital implants.

A follow-up study of a group of 40 patients after the enucleation completed by the intra-orbital acrylic spherical magnetic implant (Roper-Hall style) is presented. The mean postoperative observation time is 3.3 years. Late complications were present in two patients: the extrusion of the implant in one of them was probably caused by his poor state due to chronic dialysis, while the traumatic luxation of the implant in the other was surgically repaired. Postoperative results in all other patients were satisfactory with the adequate orbital volume substitution and the ability of the prosthesis to twist and turn in any axis without fitting problems.

Adolescent↗
PubMed1989

[Causes and treatment of hypersensitivity in tooth root].

The review article describes aetiology and treatment of dental root hypersensitivity. The three main theories of pain transduction from the exposed dentin surface to pain receptors in dental pulp are described. In addition, therapeutic compounds used to stimulate reparatory dentin formation and mineralization of peritubular dentin are described as well. The application of resins and adhesives on exposed dentin root surfaces is advocated in cases of chronic hypersensitivity. Finally, the authors emphasize the need for correct oral hygiene and early orthodontic treatment, if indicated, to prevent gingival recession and hypersensitivity of exposed root surfaces.

Dentin Sensitivity↗