Rogério Miranda Pagnoncelli

Transference of virtual planning and planning over biomedical prototypes for dental implant placement using guided surgery

OBJECTIVES This study evaluated the transference of virtual planning and planning over biomedical prototypes for dental implant placement using guided surgery. MATERIAL AND METHODS This experiment was conducted with 11 identical replicas of a human edentulous mandible. For each mandible, models and surgical guides were manufactured using stereolithography. Simulated surgeries were performed on the prototypes. Following this, the implants were placed in the mandible replicas. Superposition of the tridimensional pre- and postoperative models was used for virtual evaluation. The real evaluation was conducted by linear measurements directly on the models. RESULTS The variations in angles and distances between the coronal, central and apical regions of the 22 implants evaluated in this study had mean values <1.45 degrees and 0.41 mm. The correlations between the positions of implant beds in each mandible were fair to very good, according to the distance analyzed and the interpretation guidelines used. CONCLUSIONS According to the results of this study, the variations found in the transference of dental implant positioning to the operative field, determined during virtual planning and obtained in surgeries simulated with biomedical prototypes, confirm the reliability of guided surgery techniques in implantology.

Effect of low-level laser therapy on incorporation of block allografts.

Objective To assess the effect of low-level laser therapy (LLLT) on the incorporation of deep-frozen block allografts in a rabbit model. Background Data Studies have shown that LLLT has beneficial effects on tissue repair and new bone formation. Methods Bone tissue was harvested from two rabbits, processed by deep-freezing and grafted into the calvaria of 12 animals, which were then randomly allocated into two groups: experimental (L) and control (C). Rabbits in group L were irradiated with an aluminum gallium arsenide diode laser (AlGaAs; wavelength 830 nm, 4 J/cm2), applied to four sites on the calvaria, for a total dose of 16 J/cm2 per session. The total treatment dose after eight sessions was 128 J/cm2. Animals were euthanized at 35 (n = 6) or 70 days (n = 6) postoperatively. Results Deep-freeze-processed block allografts followed by LLLT showed incorporation at the graft-host interface, moderate bone remodeling, partial filling of osteocyte lacunae, less inflammatory infiltrate in the early postoperative period, and higher collagen deposition than the control group. Conclusion Optical microscopy and scanning electron microscopy showed that allograft bone processed by deep-freezing plus LLLT is suitable as an alternative for the treatment of bone defects. Use of the deep-freezing method for processing of bone grafts preserves the structural and osteoconductive characteristics of bone tissue.

Uso de Terapia com Laser de Baixa Intensidade na Cirurgia Bucomaxilofacial

Resumo O laser de baixa intensidade age como um fotobiomodulador teciduar, produzindo efeitos terapeuticos. Varias aplicacoes tem sido descritas na literatura, com variados protocolos de irradiacao. Muitos estudos demonstram a sua efectividade, e outros demonstram o contrario. Este artigo e uma revisao bibliografica da laserterapia, incluindo historico, tipos de laser de baixa intensidade, caracteristicas fisicas, mecanismos de funcionamento, contra-indicacoes, efeitos e aplicacoes na cirurgia bucomaxilofacial. As aplicacoes da laserterapia em implantologia, lesoes mucosas, herpes, conducao nervosa, cirurgias periodontais, disfuncao temporomandibular, apicetomias e cirurgia dentoalveolar serao especificamente abordados.

Treatment of lip hemangioma using forced dehydration with induced photocoagulation via diode laser: report of three cases

Several vascular lesions are related to the lip area. There is no universally accepted protocol for the treatment of hemangiomas and vascular malformations. In the oral cavity, high-power lasers represent an excellent therapeutic option for this type of lesion. Their coagulative properties allow for the performance of procedures without the risk of bleeding, which promotes a better healing pattern and a differentiated postoperative appearance. This study describes three cases of lip hemangioma treated with forced dehydration with induced photocoagulation (FDIP) via diode laser. All the reported cases were followed up until complete healing of the operated area had total remission of lesions, with no complications or adverse effects. The findings of the present study suggest that FDIP is effective and useful in the treatment of hemangiomas in the oral cavity. Laser treatment of these lesions prevents their recurrence and is well tolerated by patients.

Virtual Planning for Dental Implant Placement Using Guided Surgery

Technical and scientific advances in diagnostic and therapeutic methods in the biomedical field have substantially increased the predictability and longevity of the outcomes of restorative surgical procedures. In contemporary oral implantology, bioprototyping techniques based on computer-aided design and computer-aided manufacturing (CAD/CAM) technology have proven to be valuable aids in diagnosis, treatment planning, and surgical intervention. Among other aspects, use of these technologies improves preoperative planning, makes it easier for patients to understand proposed procedures, increases the predictability of treatment, and may reduce surgical morbidity. The preliminary stages that precede dental implant surgery are as important as the actual operative intervention itself, or even more so. Inadequate placement of implants may injure important anatomical structures or lead to aesthetic or functional compromise of the prosthetic stage of oral rehabilitation. Implant planning and placement can be based solely on computed tomography data and surgical guides fashioned after diagnostic models. However, direct three-dimensional visualization of the surgical site and real-model simulation of the intended surgical procedure can play a significant role in obtaining outcomes that are more consistent with the original treatment plan. Biomedical prototypes, or biomodels, provide faithful reproductions of the patient’s bone condition, thus enabling this type of assessment. Likewise, the surgery itself can be made safer and less invasive with use of individualized surgical guides for implant placement. The development of software programs for implant placement planning and the integration of these software packages with rapid prototyping methods have made fabrication of such guides possible. The process of obtaining and reformatting computed tomography (CT) data, planning implant placement over a virtual model, fabricating a surgical guide with prototyping methods, and using this guide or template during dental implant surgery with specifically designed systems may be referred to as guided implant surgery.

Sentimentos, Percepções e Manifestações de Pacientes e Profissionais Sobre a Cirurgia Ambulatorial de Terceiros Molares

Resumen pt: Objetivo: Avaliar sentimentos, percepcoes e manifestacoes de pacientes submetidos a exodontias de terceiros molares inferiores retidos e dos profissionai...

Bone Substitutes in Le Fort I Osteotomy to Promote Bone Union and Skeletal Stability

Maxillary advancement by Le Fort I osteotomy has become the standard procedure to restore function and facial esthetics, correct skeletal and occlusal discrepancies, and treat obstructive sleep apnea in patients with facial deformities. Incomplete ossification between the bone segments at the jaw osteotomy site has proven to be a major problem in these patients. There are several studies in the literature that address orthognathic surgery, but only a limited number that discuss the use of graft materials in maxillary osteotomy. Bone grafts were introduced in recent decades in order to promote and improve bone union and prevent the formation of gaps. This study will discuss the results obtained using bone substitutes in orthognathic surgery for maxillary advancement and maxillary repositioning with Le Fort I osteotomy, in a clinical report and a literature review, covering the main indications and specifying the type of material used and the stability of the surgical procedure postoperatively.

Incorporação do hormônio do crescimento humano recombinante (rhGH) em matriz de polímero biodegradável

ObjectiveIncorporate recombinant human growth hormone in a biodegradable polymer (PLGA).Material and methodThe arrays were fabricated by solvent evaporation technique. A mixture of polymer (poly lactic glycolic acid) and recombinant human growth (Saizen® Merck Serono SA Aubonne, Switzerland) was performed hormone. This mixture was poured into circular molds silicone 01cm in diameter and about 02mm thick, and carried into a drying chamber for evaporation of solvent for 48 hours. After this period, the matrices were immersed in PBS and passed through a constant temperature bath (test for hydrolytic degradation) in vitro, at a temperature of 37°C. The samples were removed from the bath in the range of 01, 02, 03, 04, 07, 10, 14 days. Mass loss, pH and concentration of hormone released as a function of time was measured.ResultThe concentration of hormone released versus time was increased until the third day. On the fourth day had a fall and on the seventh day there have been increased hormone released by the tenth day, the fourteenth day was falling again. The pH had a sharp drop from 7.4 to 3.2 on the first day and keeping a small drop until the fourteenth day. The mass loss was a gradual loss in relation to time as was to be expected.ConclusionPLGA is a good biomaterial for making breeders of growth hormone. It has proved possible to incorporate the rhGH in the array so as to then develop a bone substitute.

Effect of Recombinant Human Growth Hormone on Osseointegration of Titanium Implants: A Histologic and Biomechanical Study in Rabbits

To evaluate the action of recombinant human growth hormone (rhGH) on osseointegration of titanium implants in rabbits. Fourteen adult New Zealand rabbits, aged 30 weeks, were used in the study, and randomly divided into 2 groups. In each animal, 2 (2.2 mm × 6 mm) pure titanium implants were placed in the left tibia. In one group (test group), 1 IU (0.3 mg) of rhGH as a lyophilized powder was applied to each osteotomy site prior to implant placement. Only titanium implants were placed in osteotomy sites of the other group (control). Animals were humanely killed at 14 and 42 days after surgery, and samples were then prepared for histologic analysis and biomechanical test. The biomechanical test showed tensile pull-out stress values of 33.88 N/cm(2) for controls and 59.26 N/cm(2) for the rhGH group at 14 days and 25.99 N/cm(2) and 29.69 N/cm(2) for the control and the test group, respectively, at 42 days. Scanning electron microscope analysis showed more uniform and abundant bone tissue in contact with the implants for the test group at 14 days, and no differences between groups at 42 days. Furthermore, histologic analysis also showed accelerated bone repair in 14 days and a more advanced stage of bone remodeling for the rhGH-treated group when compared to controls after 42 days of repair. Such results show that the topical use of rhGH induces new bone formation in the early stages of bone repair and hence accelerates osseointegration of titanium dental implants.

Modulação do processo inflamatório agudo: terapia medicamentosa e laser não ablativo revisão de literatura

Diverse traumatisms may ori- ginate acute inflammatory pro- cess in anatomic regions treated by Oral and Maxillofacial Surgery. Modulation of this process occurs when initial inflammatory mani- festations overcome the benefit of tissue regeneration. The aim of this paper is to review the relevant literature on modulation of acute inflammatory process and evalu- ate the effectiveness of low level laser therapy on this process. Key words: anti-inflammatory, in- flammation, laser, low level laser therapy.