Biomedical subjects

Renzo Guarnieri

Publications and source records attributed to Renzo Guarnieri.

5 recordsLinked to original sources

PubMed2006

Maxillary sinus augmentation using granular calcium sulfate (surgiplaster sinus): radiographic and histologic study at 2 years.

The main goal of sinus augmentation is the formation of vital bone to allow tissue integration of endosseous implants to support prosthetic rehabilitation. The aim of the present investigation was to evaluate the radiographic and histologic results when granular medical-grade calcium sulfate hemihydrate was used as a grafting material in sinuses. Forty implants plus grafting material were placed in 10 patients, representing 15 sinuses, using a one-stage technique. Radiographs were taken prior to sinus augmentation, monthly until 6 months postoperatively, 9 and 12 months after implant placement, and annually thereafter. Bone biopsies were harvested from all patients for histologic and histomorphometric evaluation.

Alveolar Process↗

PubMed2004

Medical grade calcium sulfate hemihydrate in healing of human extraction sockets: clinical and histological observations at 3 months.

BACKGROUND: Following tooth extraction, remodeling and resorption of the alveolar bone at the extraction site characterize wound healing. This produces a reduction in ridge volume and difficulties in delayed placement of implants in an ideal position. Medical grade calcium sulfate hemihydrate (MGCSH) has been proposed as a graft material in extraction sockets to minimize the reduction in ridge volume. The aim of the present study was to investigate the influence of MGCSH on the histopathologic pattern of intrasocket regenerated bone and to evaluate histologically the healed MGCSH grafted extraction socket site 3 months postextraction METHODS: MGCSH was grafted in 10 fresh human extraction sockets in 10 patients. Five post-extraction sockets were used as controls. At 3 months a cylindrical tissue specimen, 2.5 mm in diameter, was trephined from the previously grafted site followed by implant placement. Non-decalcified specimens were sectioned at a cross-horizontal plane and stained with fast green, toluidine blue, and Van Kossa stains for histological and histomorphometrical examination. RESULTS: Histologically, MGCSH was not observed in most of the specimens. Newly formed bone with lamellar arrangements was identified in all the horizontal sections with no difference between apical, medium, and coronal areas. The mean trabecular area in the coronal sections was 58.6% +/- 9.2%; in the medium sections, 58.1% +/- 6.2%; and in the apical sections, 58.3% +/- 7.8%. The differences were not statistically significant. CONCLUSION: MGCSH seems to be an ideal graft material in extraction socket bone regeneration because it is almost completely resorbable, and it allows a new trabecular bone arrangement at 3 months.

Adult↗

PubMed2002

Maxillary sinus augmentation using prehardened calcium sulfate: a case report.

Prehardened medical-grade calcium sulfate hemihydrate was placed as a grafting material for sinus floor elevation in the left posterior maxilla. After 8 months of healing, three titanium plasma-sprayed screw implants (Biolock) were placed. At the same time, a bone biopsy was harvested for histologic evaluation. The specimen was processed according to standard techniques for hard tissue histology. In both the grafted area and the previously existing area of sinus floor, the histology showed complete calcium sulfate resorption and the bone was primarily of lamellar structure. In the 5-month radiograph, a new trabecular design appeared from the periphery of the grafted area, and on the 8-month radiograph, the graft material was no longer detectable and the augmented area was filled by new tissue showing a trabecular design. This case report documented that medical-grade calcium sulfate hemihydrate, when used as a grafting material for augmentation of the sinus floor, may lead to proper osseointegration of dental implants.

Absorbable Implants↗

PubMedDate not supplied

Cementum formation around a titanium implant: a case report.

Animal studies have shown that a periodontal ligament may be produced around a titanium implant when it is in contact with fractured and retained roots. Formation of cementum and attachment connective tissue around titanium implants confirms that cementum progenitor cells are located in the periodontal ligament, since cementum and periodontal ligament are present at the implant-root interface, whereas the remainder of the implant, which is not in contact with the root, shows osseointegration. The aim was to evaluate histologically the characteristics of the tissue present between a titanium implant and a retained root, which were subsequently extracted as a result of peri-implantitis. The histologic examination revealed a continuous layer of cementum and numerous cementocytes on the implant surface. No blood vessel or collagen fibers were detected in the periodontal space. In contrast to experimental studies carried out on animals, the lack of connective tissue fibers and the presence of hypercementosis in this specimen could have been caused by the inflammatory process. Furthermore, the extrusive movement of the root might explain the presence of cementum hypertrophy. Further studies are required to establish whether the neoformation of cementum and collagen fibers on an implant in the presence of root residues occurs only in animal models or whether it may also occur in humans.

Adult↗

PubMedDate not supplied

Medial-grade calcium sulfate hemihydrate (surgiplaster) in healing of a human extraction socket--histologic observation at 3 months: a case report.

PURPOSE: Following tooth extraction, wound healing is characterized by remodeling and resorption of the alveolar bone at the extraction site. This produces reduction in ridge volume. Medical-grade calcium sulfate hemihydrate (MGCSH) has been proposed as a graft material for extraction sockets to minimize the reduction in ridge volume. The aim of this study was to investigate the influence of MGCSH on the histopathologic pattern of intrasocket regenerated bone and to evaluate histologically the healed MGCSH-grafted extraction socket site at 3 months postextraction. MATERIALS AND METHODS: MGCSH was grafted in a fresh human extraction socket, and at 3 months a cylindric tissue specimen, 2.5 mm in diameter, was trephined from the previously grafted site and an implant was placed. Non-decalcified specimens were sectioned at a horizontal plane and stained for histologic and histomorphometric evaluation. RESULTS: The mean trabecular area was 58.6% +/- 9.2% in the coronal sections, 58.1% +/- 6.2% in the middle sections, and 58.3% +/- 7.8% in the apical sections. The differences in mean trabecular area between sections were not statistically significant. DISCUSSION: It is significant that the MGCSH underwent complete resorption and replacement by newly formed bone because the most important negative attribute of other graft materials is the resorption time. Moreover, calcium sulfate shows great potential for guided bone regeneration in surgical sites. CONCLUSION: MGCSH seems to be an acceptable graft material for extraction socket bone regeneration because it is completely resorbable and allows new trabecular bone arrangement in a limited 3-month period.

Alveolar Bone Loss↗