Dexamethasone-Loaded Ureasil Hydrophobic Membrane for Bone Guided Regeneration.

Physical barrier membranes have been used to release active substances to treat critical bone defects; however, hydrophilic membranes do not present a prolonged release capacity. In this sense, hydrophobic membranes have been tested. Thus, this study aimed to develop hydrophobic membranes based on mixtures of ureasil-polyether-type materials containing incorporated dexamethasone (DMA) for the application in guided bone regeneration. The physicochemical characterization and biological assays were carried out using small-angle X-ray scattering (SAXS), an in vitro DMA release study, atomic force microscopy (AFM), a hemolysis test, and in vivo bone formation. The swelling degree, SAXS, and release results revealed that the u-PPO400/2000 membrane in the proportion of 70:30 showed swelling (4.69% ± 0.22) similar to the proportions 90:10 and 80:20, and lower than the proportion 60:40 (6.38% ± 0.49); however, an equal release percentage after 134 h was observed between the proportions 70:30 and 60:40. All u-PPO materials presented hemocompatibility (hemolysis ≤2.8%). AFM results showed that the treatments with or without DMA did not present significant differences, revealing a flat/smooth surface, with no pores and/or crystalline precipitates. Finally, in vivo results revealed that for both the commercial hydrophilic membrane and u-PPO400/2000 (70:30) after 60 days, the bone formation volume was 21%. In conclusion, hybrid membranes present unique characteristics for treating critical bone defects, considering the delayed and prolonged release results associated with the physical barrier capacity.

Strontium ranelate improves post-extraction socket healing in rats submitted to the administration of bisphosphonates.

The aim of this study was to evaluate the effect of strontium ranelate (Sr) on post-extraction socket healing in rats submitted to the administration of bisphosphonates. Sixty rats were submitted to the tooth extraction of the first lower molar after 60 days of the daily administration of saline solution (SS) or alendronate (ALN). Then, the animals were allocated into six groups namely CTR: administration of SS during the whole experiment, ALN: administration of ALN during the whole experiment, ALN/SS: application of SS for 30 days after extraction in animals previously treated with ALN, ALN/Sr: application of Sr for 30 days after extraction in animals previously treated with ALN, ALN/S60: ALN therapy interruption 30 days before the extraction followed by the application of SS for 60 days, and ALN/Sr60: ALN therapy interruption 30 days before the tooth extraction followed by the application of Sr for 60 days. The healing of the post-extraction sockets was evaluated by microCT and histomorphometry. The use of ALN induced partial bone necrosis, inflammatory infiltration, and a delay in soft tissue healing; the use of Sr improved the connective tissue organization. Sr has subtle positive effects on the post-extraction healing in animals submitted to the administration of bisphosphonate.

In vivo effectiveness of hybrid membranes with osteogenic growth peptide for bone regeneration.

Guided bone regeneration (GBR) technique helps to restore bone tissue through cellular selectivity principle. Currently no osteoinductive membrane exists on the market. Osteogenic growth peptide (OGP) acts as a hematopoietic stimulator. This association could improve the quality of bone formation, benefiting more than 2.2 million patients annually. The objective of this work was to develop membranes from ureasil-polyether materials containing OGP. The membranes were characterized by differential scanning calorimetry (DSC) and small angle X-ray scattering (SAXS). OGP was synthesized by the solid phase method. Sterilization results using gamma radiation at 24 kGy did not change the structure of the material, as confirmed by DSC. The SAXS technique revealed the structural homogeneity of the matrix. OGP was incorporated in 66.25 × 10-10  mol and release results showed that the ureasil-PPO400/PEO500 and ureasil-PPO400/PEO1900 membranes released 7% and 21%, respectively, after 48 h. In vivo results demonstrated that the amount and quality of bone tissue formed in the bone defects in the presence of ureasil-polyether membranes with OGP were similar to commercial collagen material with BMP. The results allow us to conclude that membranes with OGP have characteristics that make them potential candidates for the GBR.

Alendronate Impairs Healing of Calvaria Critical Defects After Bone Graft With Different Bone Substitute Materials.

PURPOSE: The aim of this preclinical study was to evaluate the healing of critical-sized defects (CSDs) in the calvarial bone of rats grafted with deproteinized bovine bone graft (DBB) and with a combination of hydroxyapatite (HA) and ß-tricalcium phosphate (TCP) and bisphosphonate treatment. MATERIALS AND METHODS: Eighty-four animals were randomly divided into 2 groups according to the type of solution administered: the control group (CTR, saline solution) and the test group (alendronate [ALD]; sodium alendronate-50 µg/kg/day). Medications were administered via oral gavage starting 15 days before the surgical procedure until the end of the experiment. A CSD (5 mm in diameter) was made in the calvaria of each animal, and the rats were randomly allocated to 3 subgroups according to the biomaterial used to fill the defect: coagulum, DBB, and HA/TCP. The animals were sacrificed 15 and 60 days after the surgical procedure (n = 7 animals/period/subgroup). Microcomputed tomography was used to evaluate the percentage of mineralized tissues (volume). The amount of newly formed bone and remaining bone substitute material in the calvaria were analyzed by histomorphometry. RESULTS: There were no differences between the CTR and ALD groups with regard to the volume of mineralized tissues. The DBB and HA/TCP subgroups of CTR animals presented a significant increase in newly formed bone compared with these subgroups of ALD animals after 60 days of healing. CONCLUSIONS: Collectively, our findings indicate that the use of oral ALD reduced bone formation in CSD in the calvaria of rats grafted with DBB and HA/TCP.

Minimally Invasive Surgery for Clinical Crown Lengthening Using Piezoelectric Ultrasound.

This case report is aimed at describing a flapless, minimally invasive clinical crown lengthening with an osteotomy performed using a piezoelectric ultrasound. A female patient complained about the amount of gum that was exposed when she smiled, which caused aesthetic discomfort. After a clinical examination, it was confirmed that the patient had excessive gum exposure in the upper arch of the dental region for teeth 14 to 24 when she smiled. The tomographic exam showed that bone tissue was at the level of the enamel-cementum junction, and gingival tissue covered a part of the anatomic crown. Virtual analysis using digital smile design (DSD) demonstrated that enlarging the clinical crowns would provide better aesthetics. The excess gingival tissue was removed from the gingival margin region with the aid of a mockup without interference to the interdental papillae. Then, osteotomy was performed using piezoelectric ultrasound until there was a 2.5 mm distance from the top of the bone crest to the new gingival margin. In the postoperative period, good repositioning of the gingival margin, absence of postoperative complications, and rapid healing of the gingival tissue were verified. After 6 months, a good aesthetic outcome was observed with stability in the level of the periodontal tissues obtained via the crown-lengthening technique. It can be concluded that the minimally invasive clinical crown-lengthening technique was effective in repositioning the gingival margin with no postoperative complications.

Cyclosporine A impairs bone repair in critical defects filled with different osteoconductive bone substitutes.

The aim of this study was to assess the influence of cyclosporine administration on the repair of critical-sized calvaria defects (CSDs) in rat calvaria filled with diverse biomaterials. Sixty animals were divided into two groups: the control (CTR) group (saline solution) and the cyclosporine (CCP) group (cyclosporine, 10 mg/kg/day). These medications were administered daily by gavage, beginning 15 days before the surgical procedure and lasting until the day the animals were euthanized. A CSD (5 mm Ø) was made in the calvaria of each animal, which was allocated to one of 3 subgroups, according to the biomaterial used to fill the defect: coagulum (COA), deproteinized bovine bone (DBB), or biphasic calcium phosphate ceramics of hydroxyapatite and ß-phosphate tricalcium (HA/TCP). Euthanasia of the animals was performed 15 and 60 days after the surgical procedure (n = 5 animals/period/subgroup). Bone repair (formation) assessment was performed through microtomography and histometry, while the analyses of the expression of the BMP2, Osteocalcin, and TGFß1 proteins were performed using immunohistochemistry. The CSDs not filled with biomaterials demonstrated lower bone formation in the CCP group. At 15 days, less bone formation was observed in the CSDs filled with DBB, a smaller volume of mineralized tissue was observed in the CSDs filled with HA/TCP, and the expression levels of BMP2 and osteocalcin were lower in the CCP group compared to the CTR group. The use of cyclosporine impaired bone repair in CSD, and this effect can be partially explained by the suppression of BMP2 and osteocalcin expression.

Cyclosporine A impairs bone repair in critical defects filled with different osteoconductive bone substitutes

Abstract The aim of this study was to assess the influence of cyclosporine administration on the repair of critical-sized calvaria defects (CSDs) in rat calvaria filled with diverse biomaterials. Sixty animals were divided into two groups: the control (CTR) group (saline solution) and the cyclosporine (CCP) group (cyclosporine, 10 mg/kg/day). These medications were administered daily by gavage, beginning 15 days before the surgical procedure and lasting until the day the animals were euthanized. A CSD (5 mm Ø) was made in the calvaria of each animal, which was allocated to one of 3 subgroups, according to the biomaterial used to fill the defect: coagulum (COA), deproteinized bovine bone (DBB), or biphasic calcium phosphate ceramics of hydroxyapatite and β-phosphate tricalcium (HA/TCP). Euthanasia of the animals was performed 15 and 60 days after the surgical procedure (n = 5 animals/period/subgroup). Bone repair (formation) assessment was performed through microtomography and histometry, while the analyses of the expression of the BMP2, Osteocalcin, and TGFβ1 proteins were performed using immunohistochemistry. The CSDs not filled with biomaterials demonstrated lower bone formation in the CCP group. At 15 days, less bone formation was observed in the CSDs filled with DBB, a smaller volume of mineralized tissue was observed in the CSDs filled with HA/TCP, and the expression levels of BMP2 and osteocalcin were lower in the CCP group compared to the CTR group. The use of cyclosporine impaired bone repair in CSD, and this effect can be partially explained by the suppression of BMP2 and osteocalcin expression.

Cyclosporine A impairs bone repair in critical defects filled with different osteoconductive bone substitutes

Abstract The aim of this study was to assess the influence of cyclosporine administration on the repair of critical-sized calvaria defects (CSDs) in rat calvaria filled with diverse biomaterials. Sixty animals were divided into two groups: the control (CTR) group (saline solution) and the cyclosporine (CCP) group (cyclosporine, 10 mg/kg/day). These medications were administered daily by gavage, beginning 15 days before the surgical procedure and lasting until the day the animals were euthanized. A CSD (5 mm Ø) was made in the calvaria of each animal, which was allocated to one of 3 subgroups, according to the biomaterial used to fill the defect: coagulum (COA), deproteinized bovine bone (DBB), or biphasic calcium phosphate ceramics of hydroxyapatite and β-phosphate tricalcium (HA/TCP). Euthanasia of the animals was performed 15 and 60 days after the surgical procedure (n = 5 animals/period/subgroup). Bone repair (formation) assessment was performed through microtomography and histometry, while the analyses of the expression of the BMP2, Osteocalcin, and TGFβ1 proteins were performed using immunohistochemistry. The CSDs not filled with biomaterials demonstrated lower bone formation in the CCP group. At 15 days, less bone formation was observed in the CSDs filled with DBB, a smaller volume of mineralized tissue was observed in the CSDs filled with HA/TCP, and the expression levels of BMP2 and osteocalcin were lower in the CCP group compared to the CTR group. The use of cyclosporine impaired bone repair in CSD, and this effect can be partially explained by the suppression of BMP2 and osteocalcin expression.

Effects of an Er,Cr:YSGG Laser on Bone Regeneration in Critical-Sized Calvarial Defects of Rats Exposed to Inhalation of Cigarette Smoke.

Objective: To evaluate the effect of the Er,Cr:YSGG laser on healing of critical-sized calvarial defects (CSDs) in rats submitted to inhalation of cigarette smoke. Background: Smoking has been implicated with the delay in the bone healing after osteotomy procedures, then the use of the Er,Cr:YSGG laser for osteotomy in smokers could be an alternative to the conventional drills. Methods: One hundred animals were randomly allocated into four groups: trephine-the CSDs were made with a trephine drill in healthy rats; Er,Cr:YSGG-the CSDs were made with the Er,Cr:YSGG laser in healthy rats; Trephine-S-the CSDs were made with a trephine drill in rats exposed to cigarette smoke; and Er,Cr:YSGG-S-the CSDs were made with the Er,Cr:YSGG laser in rats exposed to cigarette smoke. The inhalation of cigarette smoke started 7 days before the surgical procedure until euthanasia (immediately, 7, 15, 30, or 60 days after the surgical procedure). A histometric analysis and a histological description were performed to evaluate (1) the residual linear lengths and bone formation in the CSDs; (2) the quality of bone healing. Results: The use of Er,Cr:YSGG laser induces more bone formation compared with the trephine in smokers; however, the closure of the CSD was only superior in the Er,Cr:YSGG-S group compared to the Trephine-S group at the 60-day period. Conclusions: The use of the Er,Cr:YSGG laser stimulated the bone repair process after osteotomy procedures in animals submitted to exposure of inhalation of cigarette smoke.

Avaliação da combinação de poli (ácido láctico-co-glicólico) e poli-isopreno (Cellprene®): estudo histológico em ratos / Evaluation of the combination of poly (Lactic-Co-Glycolic Acid) and polyisoprene (Cellprene®) materials: histological study in rats

Resumo Introdução A quantidade e qualidade óssea na implantodontia é um fator de alta relevância quando se tem por objetivo instalar implantes e reabilitar pacientes. No entanto, essa disponibilidade é comprometida na maioria dos casos, havendo a necessidade da busca de novos biomateriais, membranas e substâncias para uma regeneração mais favorável. Objetivo: O objetivo deste estudo foi avaliar a resposta da neoformação óssea em defeitos críticos em calvárias de ratos utilizando scaffolds de fibras de blenda polimérica a partir de poli (ácido láctico-co-glicólico) e poli-isopreno (Cellprene®). O projeto foi aprovado pelo Comitê de Ética em Experimentação Animal. Material e método Neste estudo, foram utilizados 36 ratos (Rattus Norvegicus), variação albinus, Holtzman, adultos. Os animais foram submetidos à tricotomia na região da calota craniana e à confecção de defeitos ósseos circulares bilaterais com 5 mm de diâmetro. Os animais foram divididos em três grupos: GC - defeito sem colocação de biomaterial; GCol - scaffolds de colágeno (Bio-Gide, da empresa Geistlich Pharma Ag - Biomaterials); GPoli - scaffolds de fibras de blenda polimérica a partir de poli (ácido láctico-co-glicólico - Cellprene®). Cada grupo foi avaliado em quatro períodos experimentais (7, 15, 30 e 60 dias). Após esses períodos, os animais foram sacrificados, e as peças passaram por tramitação laboratorial de rotina e inclusão em parafina. Foram obtidos cortes semisseriados e corados pela técnica de hematoxilina e eosina para análise histométrica e histológica. Foi executada análise histométrica para avaliar a composição do tecido ósseo reparado (% osso). Os dados obtidos foram analisados estatisticamente com nível de significância de 95%. Resultado Foi verificado que o GCol apresentou maior preenchimento do defeito nos períodos de 30 e 60 dias em comparação aos GC e GPoli. Conclusão Os scaffolds de fibras de blenda polimérica a partir de poli (ácido láctico-co-glicólico) e poli-isopreno (Cellprene®) não apresentaram vantagens quando utilizados em defeitos críticos.

Abstract Introduction The bone quantity and quality in implant dentistry is a highly relevant factor when it aims the use of implants and rehabilitation in patients. However, this availability is compromised in most cases, with the need to research new biomaterials, membranes and substances for more favorable regeneration. Objective: The aim of this study was to evaluate the response of bone neoformation in critical defects in rat calvaries using polymeric blend fiber scaffolds from Poly (Lactic-Co-Glycolic Acid) and Polyisoprene (Cellprene®). The project was approved by the Animal Experimentation Ethics Committee. Material and method In this study 36 rats (Rattus Norvegicus), variation albinus, Holtzman, adults were used. The animals had trichotomy in the region of the skull and the confection of bilateral circular bone defects with a diameter of 5 mm. The animals were divided into 3 groups: Group GC - defect without biomaterial placement, Group GCol - collagen scaffolds (Bio-Gide, from Geistlich Pharma Ag - Biomaterials), Group GPoli - polymeric blend fiber scaffolds from Poly (Lactic-Co-Glycolic Acid)-Polyisoprene. Each group was evaluated in 4 experimental periods (7, 15, 30 and 60 days). After these periods the animals were sacrificed and the pieces underwent routine laboratory procedures and paraffin embedding. Semi-serial sections were obtained and stained by hematoxylin and eosin technique for histometric and histological analysis. Histometric analysis was performed to evaluate the composition of repaired bone tissue (% Bone). The data obtained were statistically analyzed with a significance level of 95%. Result It was found that the GCol group presented greater defect filling in the 30 and 60 days periods compared to the GC and GPoli groups. Conclusion Polymer blend fiber scaffolds from Poly (Lactic-Co-Glycolic Acid) and Polyisoprene (Cellprene®) did not have advantages when used in critical defects.

Use of a Non-Crosslinked Collagen Membrane During Guided Bone Regeneration Does Not Interfere With the Bone Regenerative Capacity of the Periosteum.

PURPOSE: To assess whether the use of a non-crosslinked porcine collagen type I and III bi-layered membrane inter-positioned between the periosteum and a bone defect would interfere with the bone regenerative capacity of the periosteum. MATERIALS AND METHODS: Sixty rats, each with 1 critical-size calvarial defect (CSD; diameter, 5 mm) in the parietal bone, were randomly allocated to 1 of 3 equal-size groups after CSD creation: 1) the periosteum was excised and the flap was repositioned without interposition of a membrane (no-periosteum [NP] group); 2) the flap including the periosteum was repositioned (periosteum [P] group); and 3) a non-crosslinked collagen membrane was inter-positioned between the flap, including the periosteum, and the bone defect (membrane [M] group). Micro-computed tomography, qualitative histology, immunohistochemistry, and reverse transcription real-time quantitative polymerase chain reaction were performed at 3, 7, 15, and 30 days postoperatively. RESULTS: A markedly increased radiographic residual defect length was observed in the NP group compared with the P group at 30 days. The NP group also presented a smaller radiographic bone fill area than the P group at 15 and 30 days and then the M group at 30 days. The P and M groups exhibited considerably greater expression of bone morphogenetic protein-2 and osteocalcin than the NP group at 7 days; expression of transforming growth factor-ß1 was considerably greater in the NP group at 15 days. Further, the P group presented considerably higher gene expression levels of Runx2 and Jagged1 at 7 days and of alkaline phosphatase at 3 and 15 days compared with the M and NP groups. CONCLUSION: Interposition of this specific non-crosslinked collagen membrane between the periosteum and the bone defect during guided bone regeneration interferes only slightly, if at all, with the bone regenerative capacity of the periosteum.

Systemic administration of strontium ranelate to enhance the osseointegration of implants: systematic review of animal studies.

The literature states that Strontium (Sr) is able to simultaneously stimulate bone formation and suppress bone resorption. Recent animal studies suggest that the systemic administration of Sr, in the form of strontium ranelate (SRAN), would enhance the osseointegration of implants. The purpose of the present study was to undertake a systematic review on animal studies evaluating the systemic administration of Sr to enhance the osseointegration of titanium implants and the remodeling of bone grafts. The MEDLINE (PubMed) and Scopus bibliographic databases were searched from 1950 to October 2017 for reports on the use of systemic and non-radioactive Sr to enhance the osseointegration of titanium implants and the remodeling of bone grafts in animals. The search strategy was restricted to English language publications using the combined terms: "strontium" and "implant or graft or biomaterial or bone substitute". Five studies were included, all related to the systemic administration of Sr in the form SRAN, and its effects on osseointegration of titanium implants. No studies on the use of SRAN-based therapy to enhance the remodeling of bone grafts were found. The studies differed notably with respect to the study population (healthy female rats, healthy male rats, and female rats with induced osteoporosis) and SRAN dose (ranging from 500 to 1000 mg/kg/day). Results were diverse, but a tendency suggesting positive influence of systemic SRAN administration on the osseointegration of titanium implants was observed. No major side-effects due to strontium administration were reported. Systemic Sr administration, in the form of SRAN, seems to enhance peri-implant bone quality and implant osseointegration in animals, however, at a moderate extent. Further studies, evaluating both the effects of this drug on implant osseointegration and the risk/benefit of its use, are needed to provide a rationale of this therapeutic approach.

ß-TCP/HA with or without enamel matrix proteins for maxillary sinus floor augmentation: a histomorphometric analysis of human biopsies.

BACKGROUND: It is still unclear whether enamel matrix proteins (EMD) as adjunct to bone grafting enhance bone healing. This study compared histomorphometrically maxillary sinus floor augmentation (MSFA) with ß-TCP/HA in combination with or without EMD in humans. METHODS: In ten systemically healthy patients needing bilateral MSFA, one side was randomly treated using ß-TCP/HA mixed with EMD (BC + EMD) and the other side using only ß-TCP/HA (BC). After 6 months, biopsies were harvested from grafted areas during implant installation, being histologically and histomorphometrically analyzed. Differences between the groups considering new bone formation, soft tissues, and remaining BC were statistically evaluated. RESULTS: All patients showed uneventful healing after MSFA, and dental implant installation was possible in all patients after 6 months. Histological analysis showed newly formed bone that was primarily woven in nature; it was organized in thin trabeculae, and it was occasionally in contact with residual bone substitute particles, which appeared in various forms and sizes and in advanced stage of degradation. Mean bone area was 43.4% (CI95 38.9; 47.8) for the BC group and 43.0% (CI95 36.6; 49.5) for the BC + EMD group. Mean soft tissue area was 21.3% (CI95 16.5; 26.2) for BC group and 21.5% (CI95 17.7; 25.3) for BC + EMD group, while the remaining biomaterial was 35.3% (CI95 36.6; 49.5) and 35.5% (CI95 29.6; 41.3) for BC and BC + EMD group, respectively. CONCLUSIONS: MSFA with BC resulted in adequate amounts of new bone formation allowing successful implant installation; adding EMD did not have a significant effect.

Predictability and success rate of short implants

In oral rehabilitation with dental implants, severely resorbed alveolar ridges are a challenging problem due to the reduced height of the residual bone. Continuous search for minimally invasive procedures has resulted in the conception of reduced-length dental implants, decreasing the necessary amount of bone for implantation, thereby reducing the need of bone-grafts. Given the growing demand in the field of implant dentistry and the continuous development of surgical techniques, this study aimed to review the current literature on the predictability and success rate of short implants. Relevant articles published in the PubMed database between the years of 2004 and 2014 were selected using the following key-words: short dental implants, extra-short implants, survival rate, implant, mandible, maxilla, prognosis, implant survival, implant length. Based on the literature review, we concluded that short implants showed high predictability and high success rate in the short term, therefore they are one of the current options for the rehabilitation of atrophic alveolar ridges. Further longitudinal studies are necessary to define more reliably parameters for their proper use, ensuring the achievement of high success rates and survival rates with the use of this type of implant.o assess the attitude and practice of dental professionals towards using of advance radiographic technique.

Bioactive Molecule-loaded Drug Delivery Systems to Optimize Bone Tissue Repair.

Bioactive molecules such as peptides and proteins can optimize the repair of bone tissue; however, the results are often unpredictable when administered alone, owing to their short biological half-life and instability. Thus, the development of bioactive molecule-loaded drug delivery systems (DDS) to repair bone tissue has been the subject of intense research. DDS can optimize the repair of bone tissue owing to their physicochemical properties, which improve cellular interactions and enable the incorporation and prolonged release of bioactive molecules. These characteristics are fundamental to favor bone tissue homeostasis, since the biological activity of these factors depends on how accessible they are to the cell. Considering the importance of these DDS, this review aims to present relevant information on DDS when loaded with osteogenic growth peptide and bone morphogenetic protein. These are bioactive molecules that are capable of modulating the differentiation and proliferation of mesenchymal cells in bone tissue cells. Moreover, we will present different approaches using these peptide and protein-loaded DDS, such as synthetic membranes and scaffolds for bone regeneration, synthetic grafts, bone cements, liposomes, and micelles, which aim at improving the therapeutic effectiveness, and we will compare their advantages with commercial systems.

Influence of Different Proportions of External Irrigation During the Er,Cr:YSGG Laser Irradiation on Wear and Roughness of Root Surface.

INTRODUCTION: The aim of this study was to evaluate the influence of different levels of external irrigation during irradiation with an erbium, chromium: yttrium-scandium-gallium-garnet (Er,Cr:YSGG) laser on the roughness and wear of dental tissue during scaling procedures. METHODS: Twenty-Five uniradicular bovine teeth had the proximal surfaces planed and divided into 3 regions: upper, middle and lower. The upper region was treated with hand instruments, the middle region was not treated and served as a control, and the lower region was treated by the Er,Cr:YSGG laser. The teeth were randomly divided into five groups according to the different proportions of external irrigation used during the laser irradiation: G1: 10%; G2: 20%; G3: 30%; G4: 40% and G5: 50%. The samples were analyzed for roughness and wear on the root surface irradiated with the laser. RESULTS: There were no differences in the surface roughness and wear parameters between the groups irradiated with the laser, but the laser irradiation produced a rougher surface of the dentin than treatment with hand scaling. CONCLUSION: Changes in the external irrigation level did not influence the wear and roughness of root surfaces treated with an Er,Cr:YSGG laser.

Treatment of periodontal disease with an Er,Cr:YSGG laser in rats exposed to cigarette smoke inhalation.

The purpose of this study was to evaluate the erbium, chromium:yttrium-scandiumgallium-garnet (Er,Cr:YSGG) laser irradiation in the treatment of periodontitis in rats exposed to cigarette smoke inhalation (CSI). Ligatures were placed in the maxillary second molars. After a 15-day period, the ligatures were removed and 180 animals were randomly divided into six groups: (1) CSRP group--CSI and manual scaling and root planing (SRP) treatment; (2) CL group--CSI and Er,Cr:YSGG laser irradiation; (3) CSRP + L group-CSI, SRP, and Er,Cr:YSGG irradiation; (4) SRP group-manual SRP; (5) L group--Er,Cr:YSGG irradiation; (6) SRP + L group--SRP and Er,Cr:YSGG irradiation. At 7, 15, and 30 days after treatments, animals were euthanized and histologic, histometric, immunohistochemistry, and real-time PCR analyses were performed. Histometrically, no differences were observed in the SRP, L, and SRP + L groups exposed to CSI. The CSRP group showed more bone formation at 30 days than at 15 days (p < 0.01) but less bone at 30 days than the CL group at 30 days (p < 0.05). Immunohistochemical staining was positive for osteoblasts, fibroblasts, and osteoclasts. Real-time PCR showed more (vascular endothelial growth factor) VEGF expression in the L (p < 0.05) and SRP + L (p < 0.01) groups at 30 days than at 15 days and less VEGF expression in the CSRP group at 30 days than at 15 days (p < 0.05). There was no difference in fibroblast growth factor (FGF) expression. The Er,Cr:YSGG laser irradiation promotes favorable conditions for tissue repair even in animals exposed to CSI, with similar results as those achieved from manual scaling and root planing.

Repair of Bone Defects Filled with New Calcium Aluminate Cement (EndoBinder).

INTRODUCTION: The aim of this study was to evaluate and compare the repair of bone defects filled with calcium aluminate cement (EndoBinder), mineral trioxide aggregate (MTA), and calcium hydroxide. METHODS: After mixing, the cements were inserted into bone defects (3.3 mm) mechanically created in the right and left tibias of 30 rats (Rattus norvegicus, Wistar). In the control group, the bone defects were filled with blood clot of the animal itself. After time intervals of 7, 30, and 90 days had elapsed, bone tissue biopsies (n = 5) were surgically obtained and submitted to laboratory processing. The response of bone tissue in contact with the materials was microscopically analyzed. The percentage of neoformed bone tissue in the defect was determined by means of planimetry counting points superimposed on the histologic image. RESULTS: Significant increase in the percentage of neoformed bone tissue was observed throughout the experimental periods in all groups (P < .05). For the cements EndoBinder and MTA (30 and 90 days), these percentage values were statistically higher than those of the control group (P < .05); however, they were similar to those of calcium hydroxide (P > .05). CONCLUSIONS: EndoBinder and MTA allowed complete repair of bone defects created in rat tibias.

Effect of Er,Cr:YSGG laser application in the treatment of experimental periodontitis.

The purpose of this study was to evaluate the influence of an erbium, chromium:yttrium-scandium-gallium-garnet (Er,Cr:YSGG) laser in the absence or presence of manual scaling and root planning (SRP) for the treatment of induced periodontitis in rats. Ligatures were placed in the subgingival region of the maxillary first molar. After a 7-day period, the ligatures were removed, and 40 rats were randomly divided into four groups (G), as follows: (GI) no treatment, (GII) scaling and root planning (SRP) with curettes, (GIII) Er,Cr:YSGG laser irradiation and (GIV) SRP with curettes followed by Er,Cr:YSGG laser irradiation. Seven and 30 days after the treatment, the animals were sacrificed and histologic, histometric and immunohistochemistry analyses were performed. All groups showed similar histopathological characteristics during the evaluation period. The histometric analysis was confirmed using Bonferroni and paired t tests. At 7 and 30 days, groups II, III and IV exhibited greater bone formation in the furcation area when compared to group I (p < 0.0001; p < 0.05). During the 7-day period, the groups irradiated with the laser (III and IV) showed a statistically larger new bone area than the group treated with SRP (II) (p < 0.01). Immunohistochemistry analysis revealed that the control group exhibited a higher expression of tartrate-resistant acid phosphatase (TRAP) and the receptor activator of nuclear factor κΒ ligand (RANKL) when compared to groups II, III and IV (p < 0.05). All treatments were able to reduce the inflammatory processes, consequently enabling the repair of periodontal tissues. The results achieved with the application of the Er,Cr:YSGG laser suggest that this laser can stimulate greater bone formation, especially over a shorter period of time.

Efeito do ângulo de trabalho do ultrassom e do jato de bicarbonato sobre as superfícies ranculares / Effect of the working angle of the ultrasound and the air-polishing on root surfaces

O objetivo deste estudo foi avaliar o efeito da variação do ângulo de trabalho do ultrassom magnetoestrictivo (UM) e do jato de bicarbonato (JB) sobre a rugosidade e o desgaste de raízes dentárias. Cinquenta dentes bovinos tiveram as superfícies proximais divididas em três regiões: coronal, média e apical. A região coronal foi tratada com um instrumento manual, a região apical foi tratada com o JB ou com o UM, e a região média foi mantida sem tratamento para servir como controle. Os dentes foram divididos em 11 grupos, de acordo com o tratamento aplicado e o ângulo de trabalho: UM-0°; UM-30°; UM-45°; UM-60°; UM-90°; JB-0°; JB-30°; JB-45°; JB-60°; JB-90'; PAR: instrumento manual. O teste Anova, complementado pelo teste de Tukey, foi utilizado para a análise estatística (p < 0,05). A PAR promoveu menor rugosidade e maior desgaste dentário em comparação com os valores obtidos com o UM e o JB (p <0,05). Os ângulos de 450, 600 e 90° causaram maiores desgastes e rugosidades quando o UM foi utilizado (p < 0,05), enquanto o angulo de 900 causou maiores desgastes que o angulo de 300, quando o JB foi utilizado (p < 0,05). Pôde-se concluir que o tanto o UM como o JB produziram menores desgastes e maiores rugosidades às superfícies radiculares que a raspagem com instrumentos manuais. O angulo de trabalho influenciou no desgaste e na rugosidade promovidos pelo UM, enquanto que, ao utilizar o JB, a variação do angulo de trabalho influenciou apenas no desgaste radicular.