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Biomedical subjects

C Mattout

Publications and source records attributed to C Mattout.

At least 19 recordsLinked to original sources

Conditions for success in guided bone regeneration: retrospective study on 376 implant sites.

BACKGROUND: Used alone or in association with bone, guided bone regeneration is a clinically accepted method to increase the volume of bone during implant placement. Concerns about appropriate surgical techniques and the predictability of the results questions still exist. The aim of this study was to assess the conditions for success. METHODS: Three-hundred-seventy-six implants were placed in association with 214 non-resorbable membranes. In 109 implants, the membrane was secured on a blood clot; for 213 implants, membrane was placed with autogenous bone; and for 54 implants it was placed with allogenic bone. The surgical procedure, the primary closure, the timing of re-entry, and the density of regenerated tissue were studied. RESULTS: In 19 membranes, barrier exposure occurred before 3 months in these instances, the regenerated tissue was removed; another 7 membranes were exposed between 3 and 6 months. The 188 non-exposed membranes were removed between 6 and 12 months. In cases of exposure before 3 months, the regenerated tissue was soft and then removed. After closure for 6 months or more, the regenerated tissue was dense and resistant to probe pressure. The best results were obtained when the membranes were placed with autogenous bone. CONCLUSIONS: If all the clinical steps are appropriately followed, guided bone regeneration using an autogenous bone graft and implant placement is a predictable technique for increasing bone volume.

Adult↗

Clinical evaluation of a bioabsorbable regenerative material in mandibular class II furcation therapy.

30 periodontally compromised adult subjects with mandibular buccal class II furcation defects were recruited for this study. All selected defects were treated according to the biological principles of guided tissue regeneration. The subjects were randomly assigned to 2 parallel groups. The test group (n=15) received a bioabsorbable polyglycolic-polylactic membrane (PGA/PLA group); the control group (n=15) received a non-resorbable expanded polytetrafluoroethylene membrane (ePTFE group). After initial therapy, baseline measurements were recorded including plaque index, gingival index, vertical and horizontal probing depths, clinical attachment level and depth of the recession. Recall visits were made at 1, 2, 4, 6, 8, 12, and 24 weeks. At 12 months, all baseline clinical parameters were again measured. The data analysis did not demonstrate a significant difference between the 2 groups. The vertical probing depth and attachment level changes were statistically significant in each group. The postoperative recession was 0.6 mm in the ePTFE group (p<0.05) and 0.8 mm (p<0.05) in the PGA/PLA group. Compared to the initial measurements, the mean changes in horizontal probing depth were 2.7 mm and 2.5 mm (p<0.001), corresponding to mean reductions of 41.5% and 40.9% for the ePTFE and the PGA/PLA groups respectively. The results of this study suggest that 12 months after initial surgery, similar clinical improvements can be obtained in GTR therapy of buccal class II furcation lesions, regardless of whether bioabsorbable PGA/PLA membranes or non-resorbable ePTFE membranes are used.

Adult↗

Clinical evaluation of guided bone regeneration at exposed parts of Brånemark dental implants with and without bone allograft.

This investigation evaluated guided bone regeneration with a polytetrafluoroethylene barrier membrane at exposed parts of Brånemark dental implants with and without concomitant use of decalcified freeze-dried bone allograft. Density of the regenerated tissue was also determined using a No. 23 probe at a pressure of 25 g and was graded from 1 to 5. The higher index was associated with a higher resistance of newly formed tissue to the pressure of the probe. In 19 patients, 23 defects were treated by barrier membrane alone and 11 defects by bone allograft with barrier membrane. The width and the depth of the defects were determined at the time of the implant placement and at the second-stage implant surgery. When success was defined as 0 mm of residual defect, the mean success rate was 68% for the membrane group and 90% for the membrane group with bone allograft, with no statistically significant difference between the two treatment groups. The two groups did not demonstrate a significant difference in median density index. There was a significant positive relationship between time of membrane coverage and density index. A density index of 4 was only recorded after 7 months of membrane coverage. The present findings suggest beneficial clinical effect with the use of membrane alone and freeze-dried bone allograft with membrane for guided bone regeneration. This study proposed the use of a novel density index for clinical evaluation of regenerated tissue.

Adult↗

[Function of polynuclear neutrophils in patients with juvenile periodontitis and rapidly progressing periodontitis].

It is generally assumed that early onset forms of periodontal disease (including Juvenile and Rapidly Progressive Periodontitis) are associated with a defect in neutrophil behaviour. We have investigated neutrophil functions in patients with Juvenile (J.P.) and Rapidly Progressive Periodontitis (R.P.P.). In the group of J.P. patients the directed mobility (FMLP and zymosan activated plasma) is significantly decreased. The superoxide generation in response to FMLP decreases while the PMA response is normal. In the group of R.P.P. patients no significant abnormality has been reported.

Aggressive Periodontitis↗

[Impairment of neutrophil functions: study of a family with a case of juvenile periodontitis].

Neutrophil function was assessed in family in which only one member suffered from Juvenile Periodontitis (JP). Directed mobility (fMet-Leu-Phe and zymosan-activated plasma) was decreased in all siblings without involving a seric inhibitor. Adhesion was studied by a new method which allows for the evaluation of both adhesive rate and binding strengths. The latter parameters were decreased in the parents neutrophils, but remained increased in a set of twin sisters. The specific receptor induced phagocytosis was altered in all members of the family (FC receptor: IgG-SCR, C3b and mannosylfucosyl receptor: zymosan). The superoxide generation in response to fMet-Leu-Phe was decreased while the PMA response was almost normal. These results suggest an overall abnormality of ligand-receptor interactions (C5a, fMet-Leu-Phe, Fc and C4b receptors), this defect seems to involve some membrane characteristics and underlines the absence of correlation between PMN deficiency and the clinical expression of J.P.

Adult↗

[Guided tissue regeneration: clinical and microscopic study].

A case of furcation involvement of a maxillary molar is reported. The treatment consisted in applying the concept of Controlled Tissue Regeneration using a Goretex membrane. After removal of the membrane the result is satisfactory. The membrane is then examined under transmission electronic microscope. The lateral aspect of the membrane (in contact with the proliferating epithelial tissue) show a marked bacterial proliferation.

Adult↗

[Cellular competition and healing].

Different therapeutic solutions have been tried to obtain a new attachment. Several animal experiments have studied cellular colonization of radicular surfaces exposed to the disease then planed. Only the cells from the periodontal ligament seem to be able to form a new attachment. The interposition of a membrane seem to prevent gingival and osseous tissues to interfere with the periodontal ligament. The periodontal ligament cells colonize then the radicular surface.

Animals↗

[Wound healing of a bone defect following a bone graft combined with a desmodontal tissue graft].

An experimental periodontitis was produced in the upper right and left maxillary molar regions of three dogs. The apical zone of the bony defects were marked by cutting grooves into the root surfaces. The right side was used as a control while on the left side, the bony defect was treated with a graft of ligament tissue. The graft was obtained from a neighbouring area after removing the external wall of bone and sampling with a bone chisel. Four months after the grafting the dogs were sacrificed and an optical microscopic study was performed. One of the dogs died three days after operation. In the other two dogs a reattachment was observed in the groove on the control side: coronally to the groove, a long epithelial attachment was present between the radicular wall and the connective tissue. On the experimental side of dog 1, a reattachment was obtained up to the level of the cemento-enamel junction. In dog 2, a complete failure was noted since an important epithelial growth has migrated and invaded the radicular groove.

Animals↗