Raffaele Vinci

Prevention and treatment of postoperative infections after sinus elevation surgery: clinical consensus and recommendations.

Introduction. Maxillary sinus surgery is a reliable and predictable treatment option for the prosthetic rehabilitation of the atrophic maxilla. Nevertheless, these interventions are not riskless of postoperative complications with respect to implant positioning in pristine bone. Aim. The aim of this paper is to report the results of a clinical consensus of experts (periodontists, implantologists, maxillofacial surgeons, ENT, and microbiology specialists) on several clinical questions and to give clinical recommendations on how to prevent, diagnose, and treat postoperative infections. Materials and Methods. A panel of experts in different fields of dentistry and medicine, after having reviewed the available literature on the topic and taking into account their long-standing clinical experience, gave their response to a series of clinical questions and reached a consensus. Results and Conclusion. The incidence of postop infections is relatively low (2%–5.6%). A multidisciplinary approach is advisable. A list of clinical recommendation are given.

Mandibular condylar hyperplasia: clinical, histopathological, and treatment considerations.

Abstract Condylar hyperplasia is a rare disorder characterized by an increased volume of the condyle, ramus, and mandibular body leading to facial asymmetry. We present three cases of condylar hyperplasia: two women and one man, age range 27 to 34. Clinically, all three patients showed a deviation of the mandible to the opposite side and a protruded position of the chin, hypertrophy of the lower border of the mandible, combined with an elongation of the mandibular ramus, open-bite on the deformed side, and cross-bite on the opposite side. In all three cases, scintigraphy showed an increased uptake. Radiography and CT scanning confirmed the clinical diagnosis and patients were subjected to surgery, comprising high condylectomy on the affected side with access in the pre-tragus area. The surgical piece sent to the Institute of Pathological Anatomy for histological examination revealed a nonuniform picture, in terms of both the depth of cartilage islands and the thickness of the fibrous layer covering the joint surface. Common to all three cases, however, was the apparent evolution of fibrous tissue to cartilage, and of this to compact bone tissue. At two-four years, all cases have maintained a good occlusal response. The asymmetric deformity of the mandible resulting from the rare condition of hemimandibular hyperplasia is presented and the clinical, histopathological and therapeutic aspects discussed.

A macro- and nanostructure evaluation of a novel dental implant.

Success in implant dentistry also comes from the implant macrodesign and nanostructure of its surface. Titanium implant surface treatments have been shown to enhance osseointegration, maximize bone healing, and bone-to-implant contact for predictable clinical results. The aim of the study, was to evaluate the geometric macrodesign and the surface nanostructure of a novel dental implant full contact covering (FCC) obtained by electrochemical procedures. FCC implants were analyzed by scanning electronic microscope, profilometer, and x-ray photoelectron spectroscopy and compared with commercial sandblasted and sandblasted, large-grit acid-etched dental implants. Sample analysis allowed to distinguish the different implant macrodesigns, the step and the profile of the coils that cover the fixture, and the surface characteristics. FCC implant showed novel macro-characteristic of crestal module, coils, and apical zone compared with sandblasted and sandblasted and acid-etched dental implants. Moreover, the FCC nanostructure surface showed roughness values statistically higher than the 2 other surfaces, with a more homogeneity in a peaks and valleys arrangement. Finally, the x-ray photoelectron spectroscopy analysis detected differences between the examined surfaces, with the presence of several contaminants according to the different treatment procedures. Research on new macrostructures and nano morphology should result in a better qualitative and quantitative osseointegration response, with a predictability of the clinical results and long-term success of the implants.

Biologic and clinical aspects of integration of different bone substitutes in oral surgery: a literature review

Many bone substitutes have been proposed for bone regeneration, and researchers have focused on the interactions occurring between grafts and host tissue, as the biologic response of host tissue is related to the origin of the biomaterial. Bone substitutes used in oral and maxillofacial surgery could be categorized according to their biologic origin and source as autologous bone graft when obtained from the same individual receiving the graft; homologous bone graft, or allograft, when harvested from an individual other than the one receiving the graft; animal-derived heterologous bone graft, or xenograft, when derived from a species other than human; and alloplastic graft, made of bone substitute of synthetic origin. The aim of this review is to describe the most commonly used bone substitutes, according to their origin, and to focus on the biologic events that ultimately lead to the integration of a biomaterial with the host tissue.

Maxillary sinus augmentation procedures through equine-derived biomaterial or calvaria autologous bone: immunohistochemical evaluation of OPG/RANKL in humans

Autologous bone is considered the gold standard for bone regeneration, even if different heterologous bone substitutes have been proposed to overcome the limits related to its use. The aim of this study was to analyze and to compare the molecular events switched on by autologous or heterologous bone graft insertion, focusing on TGFβ1 expression and OPG/RANKL ratio, to analyze resorption process, and estimating graft vascularization, new bone tissue deposition and its mineralization, through VEGF, BSP and SPARC expression evaluation, respectively. Patients needing pre-prosthetic rehabilitation of the posterior maxilla were treated using an equine-derived biomaterial (Group 1) or calvaria autologous bone (Group 2), according to the morphology of the bone defect. Bone graft integration was evaluated on bone samples obtained from the treated areas at the moment of dental implant insertion, by morphological and immunohistochemical analyses for TGFβ1, OPG, RANKL, VEGF, BSP, and SPARC expression. Morpho - logical analysis shows the presence of biomaterial residual granules in Group 1, in parallel to a good integration between graft and host tissue. Moderate TGFβ1 expression is seen in both Group 1 and Group 2. OPG/RANKL ratio appears higher in Group 1; VEGF expression appears very strong in Group 1 and strong in Group 2, while BSP and SPARC expression results weak in Group 1 and moderate in Group 2. Our results reveal the good integration between both types of graft and the host tissue, even though autologous graft seems to produce a faster regenerative process, as evidenced by the different expression of the investigated molecules. According to these observations, the clinical use of heterologous particulate equine-derived biomaterial may ensure long-term predictability of implantprosthetic rehabilitation, comparable to that obtained with autologous bone graft.

Correlation between Initial BIC and the Insertion Torque/Depth Integral Recorded with an Instantaneous Torque-Measuring Implant Motor: An in vivo Study

BACKGROUND Quantitative intraoperative evaluation of bone quality at implant placement site and postinsertion implant primary stability assessment are two key parameters to perform implant-supported rehabilitation properly. A novel micromotor has been recently introduced allowing to measure bone density at implant placement site and to record implant insertion-related parameters, such as the instantaneous, average and peak insertion torque values, and the insertion torque/depth integral. PURPOSE The aim of this study was to investigate in vivo if any correlation existed between initial bone-to-implant contact (BIC) and bone density and integral values recorded with the instrument. MATERIALS AND METHODS Twenty-five patients seeking for implant-supported rehabilitation of edentulous areas were consecutively treated. Before implant placement, bone density at the insertion site was measured. For each patient, an undersized 3.3 × 8-mm implant was placed, recording the insertion torque/depth integral values. After 15 minutes, the undersized implant was retrieved with a 0.5 mm-thick layer of bone surrounding it. Standard implants were consequently placed. Retrieved implants were analyzed for initial BIC quantification after fixation, dehydration, acrylic resin embedment, sections cutting and grinding, and toluidine-blue and acid fuchsine staining. Correlation between initial BIC values, bone density at the insertion site, and the torque/depth integral values was investigated by linear regression analysis. RESULTS A significant linear correlation was found to exist between initial BIC and (a) bone density at the insertion site (R = 0.96, explained variance R(2)  = 0.92) and (b) torque/depth integral at placement (R = 0.81, explained variance R(2)  = 0.66). CONCLUSIONS The system provided quantitative, reliable data correlating significantly with immediate postinsertion initial BIC, and could therefore represent a valuable tool both for clinical research and for the oral implantologist in his/her daily clinical practice.

Vascular endothelial growth factor and e-nitric oxide synthase-mediated regenerative response occurring upon autologous and heterologous bone grafts.

Bone regeneration procedures allow oral rehabilitation with dental implants also in edentulous ridges with severe bone atrophy. The integration of grafted materials with the host tissue can initiate regenerative, inflammatory and apoptotic response. Since molecular mechanisms exist at the basis of such response, the aim of this work is to investigate, by immunohistochemical analyses, the expression of proteins involved in the graft integration process, in parallel to clinical and histological modifications, occurring on sites treated with extraoral autologous bone graft deriving from the parietal region of the calvaria (eAB), intraoral autologous bone graft deriving from mandibular ramus (iAB) and heterologous bone graft from swine (hB) in human patients. In our study, the immunohistochemical expression of BSP, VEGF, eNOS in eAB samples was significantly higher (p< 0.05) compared to values recorded in iAB and hB samples. The inflammatory response, investigated by iNOS expression, was found lower in all autologous samples (eAB and iAB) compared to hB, at statistically significant values. Moreover, the expression of the pro-apoptotic molecule, Bax, resulted significantly lower (p< 0.05) in eAB than in iAB and hB samples. These values, together with the low number of apoptotic cells detected in autologous samples, suggest a good regenerative response when extraoral autologous bone graft is used in comparison to the response from the other grafts, and also suggest the use of calvaria graft as a predictable therapeutic procedure for repairing severe bone defects in oral and maxillofacial surgery, not only by clinical and biomechanical criteria, but also from a biomolecular aspect.

Influence of novel nano-titanium implant surface on human osteoblast behavior and growth.

Purpose:The aim of the study is to investigate human osteoblast-like cell behavior and growth in the presence of 3 different titanium implant surfaces. Materials:Human stem cells were first obtained and then sorted by fluorescence-activated cell sorter from mesenchymal stem cell clusters of human dental papilla. The obtained human dental papilla stem cells were induced to differentiate into osteoblast-like cells and were then analyzed by reverse transcriptase polymerase chain reaction and Western blot analyses. The cells proliferated and were cultured onto 3 different titanium discs (sandblasted, sandblasted and large-grit acid-etched, and full contact coverage [FCC]) and analyzed by scanning electron microscope. Results:In all analyses samples, a high cell activity was observed, with typical osteoblast mature morphostructural response on rough surface. The high number of osteoblast-like cells was found on titanium FCC discs. At the same time, scanning electron microscope analysis confirmed the high biocompatibility of this surface. Conclusion:The rapid maturation of the osteoblast-like cells on FCC titanium surface suggests that this structure could play a central role during initial phases of bone healing processes.

Evaluation of effects on bone tissue of different osteotomy techniques.

The aim of this study is to evaluate and compare the response of bone tissue after osteotomy carried out with either rotating cutters or with piezoelectric terminals. Bioptic samples of bone tissue were taken during operations with rotating burs and piezoelectric terminals to increase bone volume before implantology. Samples first underwent histomorphometric analysis. Subsequently, osteoblastic cells, obtained from different samples, were placed in culture and allowed to proliferate to in vitro evaluate the time to initiate growth and to reach confluence. Finally, a molecular biologic study by reverse transcription polymerase chain reaction was performed to evaluate the expression of typical osteoblastic molecular markers, such as osteoprotegerin and osteopontin. Histomorphometric analysis showed that the width of necrotic line on the osteotomic margins from samples taken using different techniques did not vary significantly. Moreover, the times of initial growth and of confluence in cells from the 2 groups did not show any statistically significant differences. However, a highly significant correlation was revealed between the age of the patient and the initial growth time and the confluence. Similarly, reverse transcription polymerase chain reaction showed that the osteoprotegerin and osteopontin expression levels did not change significantly according to the surgical technique used. In conclusion, osteotomies carried out with either instrument do not seem to substantially influence the vitality of the bone tissue. The variability of the expression levels of typical osteoblastic markers seems to be linked more to other factors than to the surgical technique used.

Morphostructural Analysis of Human Follicular Stem Cells on Highly Porous Bone Hydroxyapatite Scaffold

In this study we investigated the in vitro behaviour, morphostructure and extracellular matrix synthesis of human dental follicular stem cells (hDFSCs) isolated from human dental bud, which resulted to be positive for mesenchymal markers (CD29, CD90, CD146 and CD166) by FACS analysis. Cells were analysed by light and electronic microscopy to evaluate their biological response either at week 1, that is before differentiation, or at weeks 3–6, when they had been cultured in osteogenic medium onto a highly porous natural scaffold material (Bio-Oss®). Microscopy analysis of primary culture cells showed they had a mesenchymal stem cell-like morphostructure, spindle shaped, similar to the culture of mesenchymal stem cells derived from adult bone marrow. Also, after osteogenic differentiation, these analyses indicate typical osteoblast morphostructure and reveale a tri-dimensional organization of the cells and deposition of extracellular matrix (ECM) in close contact with biomaterial. This approach would allow to personalize the scaffold for bone tissue engineering in order to accelerate the process of osteogenesis.