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Biomedical subjects

G Brunel

Publications and source records attributed to G Brunel.

At least 37 records · Page 2Linked to original sources

[Tissue reactions induced by provoked tooth displacement in experimental periodontal lysis].

A dental appliance with a spring used to induce a mesial movement of the lower molars was placed in the mouth of two groups of golden hamsters, one control and the other submitted to the hyperglucidic diet of Keyes and Jordan. The analysis and histological comparison of the tissue reactions showed important differences in both groups. The alveolar wall remodeling in the experimental group was inhibited as well as the resorption of the hyaline zones.

Alveolar Process↗

[Changes in the granular ducts of the submandibular gland in rats subjected to dietary deficiencies].

Lack of balance in protein diets induced structural modifications of the rat submaxillary glands. The granular ducts underwent a differentiation delay and a hypodevelopment under the effect of hypo and hyperproteinic diets. The optical microscope morphometric analysis showed that the total and single surfaces of the ducts were different in the groups with abnormal hypo or hyperproteinic diets compared to the control group. In TEM, the quantitative study showed that the number of cells with dense granules and the number of these granules were decreased in the hypoproteinic group. The mean number of granules was in contrast increased in the hyperproteinic group. The results are discussed in terms of duct differentiation, secretory function of the granular cells and equilibrium of the oral cavity.

Animals↗

[Trial modeling of acinous structures of the rat sub-mandibular gland].

The sub-mandibular glands of rats subjected to unbalanced protein diets for six months were submitted to histomorphometric study in optical light microscopy. Protein deficiency led to slower growth although an hyperprotein diet did not alter acini distribution significantly. The results allowed an acinous structure model related to the diet protein ratio to be tested.

Animals↗

[Air embolus after Caesarean section (author's transl)].

This is case history of a primigravid woman on whom Caesarean section was carried out in normal conditions for fetal distress, the patient being placed in Trendelenburg position. After the abdomen had been closed there was a sudden collapse with cyanosis, right bundle branch block and then coma with hypertonicity, hyperreflexia and transitory hemiplegia. The only possible diagnosis that could be made was of air embolus following Caesarean section in the light of many investigations that were carried out and the improvement under hyperbaric oxygen treatment and the very irregular progress of the neurological symptoms. Published case histories are rare [12] (published by Walrop, 1953 and Nelson 1960) and over all the result has been unfavourable. The diagnosis can be proven when gas has been found in the blood vessels at autopsy or by the finding of certain clinical signs which indicate the presence of air in the heart or in the blood vessels (water mill sound and the sound of air in the blood vessels). Diagnosis is made by exclusion. The differential diagnosis must be made with amniotic fluid embolus and the other cerebro-vascular accidents, as well as obstetrical shock. The principal factors that bring about air embolus are the entry of air into the dilated uterine veins which is helped by the negative pressure achieved by the Trendelenburg position. As soon as this diagnosis is made it is important to start hyperbaric oxygen treatment and symptomatic resuscitation.

Adult↗

Tomodensitometric and histologic evaluation of the combined use of a collagen membrane and a hydroxyapatite spacer for guided bone regeneration: a clinical report.

In this report, the problems of insufficient bone and soft tissue after extraction of maxillary incisors were addressed concurrently prior to endosseous implant placement, by combining the use of a diphenylphosphorylazide-cross-linked Type I collagen membrane and a resorbable space-making biomaterial composed of 200-micron porous hydroxyapatite granules blended in Type I collagen and chondroitin-4-sulfate. Upon flap reflection 8 months postsurgery, the horizontal deficiencies were almost completely resolved, membranes completely resorbed and the defects filled with hard, bonelike tissue, with a few superficial hydroxyapatite granules. Histologic evaluation of the bone biopsies obtained at the implantation sites revealed dense, well-reconstructed alveolar bone with a few traces of hydroxyapatite granules that had been completely resorbed. Tomodensitometric evaluation indicated that bone regeneration ranged from 14% to 58%, with an average bone gain of 29.77%. Four nonsubmerged ITI titanium implants placed in the augmented bone have been in function for more than 5 years, with no clinical or radiographic signs of hard or soft tissue breakdown. Bacterial sampling at dental sites with periodontitis 1 month prior to periodontal therapy and at implant sites for up to 30 months demonstrated rapid colonization of implant surfaces by periodontopathogens without causing any detrimental effect to implant integration.

Absorbable Implants↗

Regeneration procedures in immediate transmucosal implants: an animal study.

The aim of the present study was to evaluate bone regeneration around nonsubmerged implants placed immediately in extraction sites in the canine mandible using a combination of synthetic hydroxyapatite (HA) and collagen membranes. Ten beagle dogs were used in this study. After the second and third mandibular premolars were extracted, hollow-screw implants were placed in the distal extraction sockets. In each animal, one site received no treatment (control site), while other defects received randomly 1 of the following treatments: grafting with porous HA in the peri-implant region, collagen membrane adapted to the implant cervical collar covering the peri-implant defects, or a combination of the 2 treatments, i.e., HA grafting and membrane placement. After 4 months of healing, block biopsies were obtained and prepared for histologic analysis using the cutting-grinding technique. The histometric evaluation took into account the number of integrated screw threads, the extent of bone-to-implant contact, and the density of peri-implant bone. At sites covered by membrane alone or by membrane and HA, the number of integrated threads was statistically higher than sites treated only with HA. The extent of bone-to-implant contact was significantly different between treatments. However, the use of bioabsorbable materials did not significantly enhance peri-implant bone regeneration in immediate implantation.

Absorbable Implants↗

A multicenter report on 1,022 consecutively placed ITI implants: a 7-year longitudinal study.

The aim of this multicenter study was to evaluate cumulative success and survival rates of ITI implants after 7 years. A complete medical report was obtained for all 440 patients enrolled in this investigation, which involved 10 different private practices. The 1,022 consecutively placed implants were distributed between completely edentulous, partially edentulous, and single-tooth replacement cases. During the annual follow-up visit, each implant was examined both clinically and radiographically using predefined success criteria. The cumulative survival and success rates were calculated for all implants. Implant subgroups were defined according to the medical history of the patients or pooled according to various indications, locations, implant designs, or implant lengths. In each subgroup, the related cumulative success rate was statistically compared to the global cumulative success rate. Fifteen implants (1.4%) were regarded as early failures, and at the end of the follow-up, the global failure rate reached 6.6%; 30 implants (3%) were lost to follow-up. At 5 years, the cumulative survival rate was 95.4%; this declined to 92.2% at 7 years. The weakest success rates were observed for implants placed in older patients, periodontally treated patients, and completely edentulous arches. Conversely, cumulative success rates that were significantly above average were observed for patients between 40 and 60 years old without pathology, implants placed after bone regeneration, solid-screw implants, implants placed in edentulous spaces, and implants placed as single-tooth replacements. This investigation has demonstrated that in these 10 private practice settings, the success rate for ITI implants remained high for up to 5 years and declined slightly between 5 and 7 years. It should be noted that in later year intervals, a relatively small number of implants remained for the analysis of cumulative success rates.

Adolescent↗