Does Melatonin Associated with Nanostructured Calcium Phosphate Improve Alveolar Bone Repair?

Background and objectives: Calcium phosphates have been widely used as bone substitutes, but their properties are limited to osteoconduction. The association of calcium phosphates with osteoinductive bioactive molecules has been used as a strategy in regenerative medicine. Melatonin has been studied due to its cell protection and antioxidant functions, reducing osteoclastic activity and stimulating newly formed bone. This study aimed to evaluate the effect of topical application of melatonin associated with nanostructured carbonated hydroxyapatite microspheres in the alveolar bone repair of Wistar rats through histological and histomorphometric analysis. Materials and Methods: Thirty female Wistar rats (300 g) were used, divided randomly into three experimental groups (n = 10), G1: nanostructured carbonated hydroxyapatite microspheres associated with melatonin gel (CHA-M); G2: nanostructured carbonated hydroxyapatite (CHA); G3: blood clot (without alveolar filling). The animals were euthanized after 7 and 42 days of the postoperative period and processed for histological and histomorphometric evaluation. Kruskal-Wallis and Dunn's post-test were applied to investigate statistical differences between the groups at the same time point for new bone and connective tissue variables. Mann-Whitney was used to assess statistical differences between different time points and in the biomaterial variable. Results: Results showed a greater volume of residual biomaterial in the CHA-M than the CHA group (p = 0.007), and there were no significant differences in terms of newly formed bone and connective tissue between CHA and CHA-M after 42 days. Conclusions: This study concluded that both biomaterials improved alveolar bone repair from 7 to 42 days after surgery, and the association of CHA with melatonin gel reduced the biomaterial's biodegradation at the implanted site but did not improve the alveolar bone repair.

In Vivo Evaluation of Permeable and Impermeable Membranes for Guided Bone Regeneration.

BACKGROUND: The degree of biodegradation and the inflammatory response of membranes employed for guided bone regeneration directly impact the outcome of this technique. This study aimed to evaluate four different experimental versions of Poly (L-lactate-co-Trimethylene Carbonate) (PTMC) + Poly (L-lactate-co-glycolate) (PLGA) membranes, implanted in mouse subcutaneous tissue, compared to a commercially available membrane and a Sham group. METHODS: Sixty Balb-C mice were randomly divided into six experimental groups and subdivided into 1, 3, 6 and 12 weeks (n = 5 groups/period). The membranes (1 cm2) were implanted in the subcutaneous back tissue of the animals. The samples were obtained for descriptive and semiquantitative histological evaluation (ISO 10993-6). RESULTS: G1 and G4 allowed tissue adhesion and the permeation of inflammatory cells over time and showed greater phagocytic activity and permeability. G2 and G3 detached from the tissue in one and three weeks; however, in the more extended periods, they presented a rectilinear and homogeneous aspect and were not absorbed. G2 had a major inflammatory reaction. G5 was almost completely absorbed after 12 weeks. CONCLUSIONS: The membranes are considered biocompatible. G5 showed a higher degree of biosorption, followed by G1 and G4. G2 and G3 are considered non-absorbable in the studied periods.

"Dry oral and ocular manifestations and autoantibodies characteristic of primary Sjögren's syndrome in multiple sclerosis".

INTRODUCTION: The relationship between primary Sjögren syndrome (pSS) and demyelinating diseases is still not well understood. These diseases seem to coexist amidst autoimmunity, raising questions about clinical characteristics, relationship with immunomodulatory treatment, and possible common immunological background underlying their pathogenesis. OBJECTIVE: calculate the frequency of dry oral and ocular manifestations and autoantibodies characteristic of primary Sjögren's Syndrome in Multiple Sclerosis. METHODS: 202 patients with multiple sclerosis answered a questionnaire to identify complaints of xerostomia and xerophthalmia, according to diagnostic criteria for primary Sjögren's syndrome; 43 answered positively to at least one question; 27 had comorbidities or used drugs that cause dry symptoms and were excluded; 16 patients were selected for examinations for oral, ocular and serum anti-Ro/SS-A autoantibody evaluation. RESULTS: Eleven (68.75%) patients complained of xerostomia; 14 (87.5%) of xerophthalmia. Sialometry < 0.1 ml/min was observed in three (18.8%); 13 patients underwent minor salivary gland biopsy and histopathological examination: focal score > 1 in three (23.1%). Schirmer test was < 5 mm/5 min in four (25%). Lyssamine green/fluorescein dye score was > 5 in three (18.8%). Anti-Ro/SS-A > 10 UI/mm in two (12.5%). Three (1,49%) patients met current criteria for primary Sjögren's syndrome. CONCLUSIONS: Patients with MS may report xerostomia and/or xerophthalmia even in the absence of comorbidities and use of medications capable of causing these symptoms, which may fulfill the diagnostic criteria for pSS. In this study, the frequency of pSS according to current criteria was within the range observed in the literature with older criteria. But the question remains whether the association between these diseases is fortuitous or whether there is a pathogenic link.

Acquired oral syphilis: A multicenter study of 339 patients from South America.

OBJECTIVE: To report the clinicopathologic features of acquired oral syphilis cases in South American countries. MATERIALS AND METHODS: Clinical data were retrospectively collected from the records of 18 oral diagnostic services in Argentina, Brazil, Chile, Colombia, Venezuela, Uruguay, and Peru. Serologies of nontreponemal and treponemal tests were used for diagnosis. RESULTS: The series comprised 339 cases of acquired oral syphilis. Secondary syphilis ranked as the most common stage (86.7%). Lesions were more frequent among males (58.0%) and young adults with a mean age of 33.3 years. Individuals aged 20-29 years were most affected (35.3%). The most commonly involved sites were the tongue (31.6%), lip/labial commissure (25.1%), and hard/soft palate (20.4%). Clinically, acquired oral syphilis usually presented as mucous patches (28.4%), papules (25.7%), and ulcers (18.1%). Skin manifestations occurred in 67.7% of individuals, while lymphadenopathy and fever were observed in 61.3% and 11.6% of all subjects, respectively. Most patients were treated with the benzathine penicillin G antibiotic. CONCLUSION: This report validates the spread of acquired oral syphilis infection among young adults in South America. Our directives include accessible diagnostic tools for proper disease screening, surveillance, and counselling of affected individuals, especially in low- and middle-income countries.

In Vivo Biological Evaluation of Orthodontically Moved Incisors after Replantation.

Background and Objectives: There is still considerable controversy regarding the possibility of submitting replanted teeth to orthodontic movement (OM). The purpose of the present study was to evaluate the tissue response after orthodontic movement on replanted teeth. Materials and Methods: Sixty Wistar rats were randomly assigned to four groups (n = 15): G1, replantation without OM after 30 days; G2, replantation with OM after 30 days; G3, replantation without OM after 60 days, and G4, replantation with OM after 60 days. The maxillary left central incisors were extracted and the teeth were stored in milk media. After 30 min, the teeth were replanted and fixed with non-rigid immobilization. All specimens were observed after 30 and 60 days of replantation and then subdivided into two subgroups (with OM or without OM). The animals were euthanized after seven days of the OM started, and the maxillary bone blocks were processed for histological evaluation. Results: The histological results showed periodontal ligament repair in both periods studied without OM; however, ankylosis and root resorption was seen in all orthodontically moved teeth. Conclusions: The orthodontic movement did not favor tissue response in all replanted teeth, regardless of the experimental periods.

Microspheres of alginate encapsulated minocycline-loaded nanocrystalline carbonated hydroxyapatite: therapeutic potential and effects on bone regeneration.

Background and objective: Tetracycline and its derivatives, combined with calcium phosphates, have been proposed as a delivery system to control inflammatory processes and chronic infections. The objective of this study was to evaluate the microspheres of alginate encapsulated minocycline-loaded nanocrystalline carbonated hydroxyapatite (CHAMINO) as a biomimetic device to carry out target-controlled drug delivery for alveolar bone repair. Methods: CHAMINO microspheres were implanted in a rat central incisor socket after 7 and 42 days. New bone was formed in both groups between 7 and 42 days of implantation. However, the bone growth was significantly higher for the CHAMINO microspheres. Results: The minocycline (MINO) loading capacity of the nanocrystaline carbonated hydroxyapatite (CHA) nanoparticles was 25.1±2.2 µg MINO/mg CHA for adsorption over 24 hrs. The alginate microspheres containing minocycline-loaded CHA were biologically active and inhibited the Enterococcus faecalis culture growth for up to seven days of the MINO release. An osteoblastic cell viability assay based on the resazurin reduction was conducted after the cells were exposed to the CHAMINO powder and CHAMINO microspheres. Thus, it was found that the alginate extracts encapsulated the minocycline-loaded CHA microspheres and did not affect the osteoblastic cell viability, while the minocycline-doped CHA powder reduced the cell viability by 90%. Conclusion: This study concluded that the alginate microspheres encapsulating the minocycline-loaded nanocrystalline carbonated hydroxyapatite exhibited combined antibacterial activity against Enterococcus faecalis with cytocompatibility and osteoconduction properties. The significant improvement in the new bone formation after 42 days of implantation suggests that the CHAMINO microsphere has potential in clinical applications of bone regeneration.

Diagnóstico e tratamento de Sialolitíase: relato de caso / Diagnosis and treatment of Sialolithiasis: Case Report

Sialolitos são estruturas calcificadas, que se desenvolvem no interior do sistema ductal salivar, em decorrência da deposição de sais de cálcio ao redor de um acúmulo de restos orgânicos no lúmen do ducto glandular. Acometem, com mais assiduidade, a glândula submandibular e são a causa mais comum de inflamações agudas ou crônicas nas glândulas salivares maiores. Manifestam-se, com maior frequência, em indivíduos adultos de meia-idade, e os sinais e sintomas mais comuns são a dor e a tumefação local. Podem ser evidenciados por radiografias convencionais, tomografia computadorizada, ressonância magnética, ultrassonografia, cintilografia, sialoendoscopia e sialografia. O tratamento inclui a eliminação espontânea mediante orientações ou uso de medicamentos, ou a remoção cirúrgica do sialolito, sendo necessária, em alguns casos, a exérese da própria glândula. Este trabalho tem como objetivo relatar o caso clínico do paciente S.L.M, 44 anos de idade, sexo feminino, caucasiana, atendida na clínica de Cirurgia Bucal da Universidade Federal Fluminense, apresentando um sialolito no sistema ductal da glândula submandibular do lado esquerdo. A paciente foi submetida à remoção cirúrgica do sialolito sob anestesia local, sem maiores intercorrências... (AU)

Sialolites are calcified structures that develop inside the salivary ductal system, due to the deposition of calcium salts around an accumulation of organic remains in the lumen of the glandular duct. They have a more frequent involvement of the submandibular gland and are the most common cause of acute or chronic inflammation in the major salivary glands. They occur more frequently in middle-aged adult patients and the most common signs and symptoms are local pain and swelling. They can be evidenced by conventional radiography, computed tomography, MRI, ultrasonography, scintigraphy, sialoendoscopy and sialography. Treatment includes spontaneous elimination, from guidelines or use of medications, or surgical removal of sialolite, in some cases, the excision of the gland itself. This study aims to report the clinical case of the patient S.L.M, 44 years old, female, Caucasian, attended at the Oral Surgery Clinic of the Federal Fluminense University, presenting a sialolite in the ductal system of the left submandibular gland. The patient was submitted to surgical removal of the sialolite, under local anesthesia, without major intercurrences... (AU)

Alveolar bone repair with strontium- containing nanostructured carbonated hydroxyapatite.

This study aimed to evaluate bone repair in rat dental sockets after implanting nanostructured carbonated hydroxyapatite/sodium alginate (CHA) and nanostructured carbonated hydroxyapatite/sodium alginate containing 5% strontium microspheres (SrCHA) as bone substitute materials. Twenty male Wistar rats were randomly divided into two experimental groups: CHA and SrCHA (n=5/period/group). After one and 6 weeks of extraction of the right maxillary central incisor and biomaterial implantation, 5 µm bone blocks were obtained for histomorphometric evaluation. The parameters evaluated were remaining biomaterial, loose connective tissue and newly formed bone in a standard area. Statistical analysis was performed by Mann-Withney and and Wilcoxon tests at 95% level of significance. The histomorphometric results showed that the microspheres showed similar fragmentation and bio-absorbation (p>0.05). We observed the formation of new bones in both groups during the same experimental periods; however, the new bone formation differed significantly between the weeks 1 and 6 (p=0.0039) in both groups. The CHA and SrCHA biomaterials were biocompatible, osteoconductive and bioabsorbable, indicating their great potential for clinical use as bone substitutes.

Alveolar bone repair with strontium- containing nanostructured carbonated hydroxyapatite

ABSTRACT Objective: This study aimed to evaluate bone repair in rat dental sockets after implanting nanostructured carbonated hydroxyapatite/sodium alginate (CHA) and nanostructured carbonated hydroxyapatite/sodium alginate containing 5% strontium microspheres (SrCHA) as bone substitute materials. Methods: Twenty male Wistar rats were randomly divided into two experimental groups: CHA and SrCHA (n=5/period/group). After one and 6 weeks of extraction of the right maxillary central incisor and biomaterial implantation, 5 μm bone blocks were obtained for histomorphometric evaluation. The parameters evaluated were remaining biomaterial, loose connective tissue and newly formed bone in a standard area. Statistical analysis was performed by Mann-Withney and and Wilcoxon tests at 95% level of significance. Results: The histomorphometric results showed that the microspheres showed similar fragmentation and bio-absorbation (p>0.05). We observed the formation of new bones in both groups during the same experimental periods; however, the new bone formation differed significantly between the weeks 1 and 6 (p=0.0039) in both groups. Conclusion: The CHA and SrCHA biomaterials were biocompatible, osteoconductive and bioabsorbable, indicating their great potential for clinical use as bone substitutes.

Randomized clinical trial for the biological evaluation of two nanostructured biphasic calcium phosphate biomaterials as a bone substitute.

BACKGROUND: The presence of nonresorbable residual granules of hydroxyapatite (HA) may decrease the bone/implant interface. To balance resorption and bone formation biphasic calcium phosphate ceramics compounds applied at different rates have been studied. PURPOSE: The aim of this trial was to compare the clinical, histological, and histomorphometric responses of two new biphasic calcium phosphate biomaterials in fresh dental sockets after 3 and 6 months. MATERIALS AND METHODS: Forty-eight volunteers were divided randomly and double-blindly into 4 groups of 12 individuals: Clot (C), BoneCeramic (BC), Biomaterial 1 (B1), and Biomaterial 2 (B2) groups. Three and six months later, samples were obtained, and histological and histomorphometric sections were evaluated, focusing on the presence of fibrous connective tissue (CT) and newly formed bone. Statistical analysis was performed (P < .05%). RESULTS: The quantification of crystalline phases showed B1 composed of HA (60.28%) and ß-TCP (39.72%); B2 composed of HA (78.21%) and ß-TCP (21.79%); and BC composed of HA (61%) and ß-TCP (39%). The B1 group showed the most newly formed bone (69.3% ± 6.03%), followed by the BC (51.6 ± 12.34%), B2 (46.6 ± 7.66%), and C groups (45.4 ± 7.98%), and less connective tissue and biomaterial remained in the B1 group after 6 months. CONCLUSION: B1 group showed the greatest amount of newly formed bone after 6 months.

Técnica de Shira utilizada no tratamento de mucocele: Quando indicar? Como realizar? / Shira's technique used in mucocele treatment: when indicate? How to perform?

O termo mucocele é empregado clinicamente como um termo genérico, para se referir aos fenômenos de retenção e extravasamento de muco, sendo essa lesão um pseudocisto de etiologia traumática, decorrente do rompimento do ducto de uma glândula salivar menor. Clinicamente, esse tipo de lesão pode se apresentar como uma tumefação ou bolha, macia à palpação, de coloração azulada ou, mesmo, normocrômica, dependendo da sua profundidade nos tecidos, assintomática, de superfície lisa e de tamanho variado, sendo o lábio inferior a região mais acometida. Com relação ao seu tratamento, a enucleação é a técnica mais preconizada. Entretanto, algumas técnicas alternativas têm sido propostas na literatura para esse fim, como o uso do laser de dióxido de carbono, marsupialização e a técnica de Shira, sendo esta realizada com a injeção prévia de um hidrocoloide irreversível no interior da lesão, para evitar o extravasamento do conteúdo mucoso no momento da divulsão cirúrgica. O objetivo deste trabalho é mudar o caso clínico da paciente encaminhada à Clínica de Cirurgia Oral menor da Universidade Federal Fluminense, lhe apresentou, ao exame clínico, uma mucocele em lábio inferior do lado direito, com 14 dias de evolução e cerca de 2,0 cm em seu maior diâmetro, tendo sido realizado remoção completa da lesão por meio da técnica de Shira. A paciente evoluiu sem complicações e recidiva da lesão... (AU)

The mucocele term is used clinically as a generic term to refer to retention phenomenon and mucus extravasation, which is a pseudocyst injury of traumatic etiology, due to the rupture of the duct of a minor salivary gland. Clinically this type of injury may present as a swelling or blister, soft palpation, bluish or even normochromic coloring, depending on their depth in the tissues, asymptomatic smooth surface and varying size, with the lower lip the most affected region. Regarding treatment, enucleation is the recommended technique. However, some alternative techniques have been proposed in the literature for this purpose, such as using carbon dioxide laser, Marsupialization and Shira's technique, which is performed with the previous injection of an irreversible hydrocolloid inside the lesion to avoid extravasation the mucous content at the time of surgical divulsion. The aim of this paper is to present a case of C.R.F. patient, 18-year-old female was referred to minor oral surgery clinic of the Federal Fluminense University, with clinical examination mucoceles in lower right lip 14 days of evolution and about 2.0 cm in its largest diameter, where complete removal of the lesion was performed using the Shira's technique. The same progressed without complications and recurrence of injury... (AU)

Physico-chemical and Histomorphometric Evaluation of Zinc-containing Hydroxyapatite in Rabbits Calvaria.

The aim of this study was to characterize the physico-chemical properties and bone repair after implantation of zinc-containing nanostructured porous hydroxyapatite scaffold (nZnHA) in rabbits' calvaria. nZnHA powder containing 2% wt/wt zinc and stoichiometric nanostructured porous hydroxyapatite (nHA - control group) were shaped into disc (8 mm) and calcined at 550 °C. Two surgical defects were created in the calvaria of six rabbits (nZnHA and nHA). After 12 weeks, the animals were euthanized and the grafted area was removed, fixed in 10% formalin with 0.1 M phosphate buffered saline and embedded in paraffin (n=10) for histomorphometric evaluation. In addition, one sample from each group (n=2) was embedded in methylmethacrylate for the SEM and EDS analyses. The thermal treatment transformed the nZnHA disc into a biphasic implant composed of Zn-containing HA and Zn-containing ß-tricalcium phosphate (ZnHA/ßZnTCP). The XRD patterns for the nHA disc were highly crystalline compared to the ZnHA disc. Histological analysis revealed that both materials were biologically compatible and promoted osteoconduction. X-ray fluorescence and MEV-EDS of nZnHA confirmed zinc in the samples. Histomorphometric evaluation revealed the presence of new bone formation in both frameworks but without statistically significant differences (p>0.05), based on the Wilcoxon test. The current study confirmed that both biomaterials improve bone repair, are biocompatible and osteoconductive, and that zinc (2wt%) did not increase the bone repair. Additional in vivo studies are required to investigate the effect of doping hydroxyapatite with a higher Zn concentration.

Physico-chemical and Histomorphometric Evaluation of Zinc-containing Hydroxyapatite in Rabbits Calvaria

Abstract The aim of this study was to characterize the physico-chemical properties and bone repair after implantation of zinc-containing nanostructured porous hydroxyapatite scaffold (nZnHA) in rabbits' calvaria. nZnHA powder containing 2% wt/wt zinc and stoichiometric nanostructured porous hydroxyapatite (nHA - control group) were shaped into disc (8 mm) and calcined at 550 °C. Two surgical defects were created in the calvaria of six rabbits (nZnHA and nHA). After 12 weeks, the animals were euthanized and the grafted area was removed, fixed in 10% formalin with 0.1 M phosphate buffered saline and embedded in paraffin (n=10) for histomorphometric evaluation. In addition, one sample from each group (n=2) was embedded in methylmethacrylate for the SEM and EDS analyses. The thermal treatment transformed the nZnHA disc into a biphasic implant composed of Zn-containing HA and Zn-containing β-tricalcium phosphate (ZnHA/βZnTCP). The XRD patterns for the nHA disc were highly crystalline compared to the ZnHA disc. Histological analysis revealed that both materials were biologically compatible and promoted osteoconduction. X-ray fluorescence and MEV-EDS of nZnHA confirmed zinc in the samples. Histomorphometric evaluation revealed the presence of new bone formation in both frameworks but without statistically significant differences (p>0.05), based on the Wilcoxon test. The current study confirmed that both biomaterials improve bone repair, are biocompatible and osteoconductive, and that zinc (2wt%) did not increase the bone repair. Additional in vivo studies are required to investigate the effect of doping hydroxyapatite with a higher Zn concentration.

Resumo O objetivo deste estudo foi caracterizar físico-químicamente e avaliar o reparo ósseo de discos de hidroxiapatita porosa contendo zinco após a implantação em calvária de coelhos (nZnHA). O pó de nZnHA e o pó hidroxiapatita porosa estequiométrica nanoestruturada (controle - nHA) foram confeccionados em discos (8 mm) e calcinados a 550˚C. Dois defeitos cirúrgicos foram criados na calvária de seis coelhos para a implantação dos discos. Após 12 semanas, os animais foram eutanasiados e as áreas enxertadas foram removidas, fixadas em formol a 10% e embebidas em parafina (n=10) para avaliação histomorfométrica. Além disso, uma amostra de cada grupo (n=2) foi embebida em metilmetacrilato para análise de MEV e EDS. O tratamento térmico dos discos de nZnHA transformou-os em implantes bifásicos compostos por HA contendo Zinco e β fosfato tricálcico com Zinco (ZnHA/βZnTCP). Os discos de nHA, apresentaram-se altamente cristalinos e com baixa solubilidade quando comparados aos discos de ZnHA. A análise histológica revelou que ambos os materiais foram biologicamente compatíveis e promoveram a osteocondução. As análises de FRX e MEV-EDS confirmaram a presença do zinco nas amostras de nZnHA. A avaliação histomorfométrica revelou a presença de neoformação óssea em ambos os grupos, porém sem diferenças estatísticas entre eles, com base no teste de Wilcoxon (p>0,05). O presente estudo confirmou que ambos os biomateriais otimizaram o reparo ósseo, foram biocompatíveis e osseocondutivos e a presença do zinco não favoreceu o reparo ósseo. Estudos adicionais in vivo devem ser conduzidos a fim de investigar o efeito de maiores concentrações de zinco.

Histomorphometric evaluation of strontium-containing nanostructured hydroxyapatite as bone substitute in sheep.

The aim of this study is to evaluate the biocompatibility and osteoconductivity in surgical defects of sheep tibias filled with 1% strontium-containing nanostructured hydroxyapatite microspheres (SrHA), stoichiometric hydroxyapatite without strontium microspheres (HA), or blood clots. Santa Ines sheep were subjected to three perforations on the medial side of the left tibia. The biomaterials were characterized by X-ray Diffraction (XRD) and Fourier Transform Infrared (FTIR) before implantation and by X-Ray Microfluorescence (µFRX) and Scanning Electron Microscopy (SEM) after sheep tibias implantation. Surgical defects were filled with blood clots (control), SrHA (Group 1) or HA (Group 2). After 30 days, 5-µm bone blocks were obtained for histological evaluation, and the blocks obtained from 1 animal were embedded in methylmethacrylate for undecalcified sections. Mononuclear inflammatory infiltrate remained mild in all experimental groups. Giant cells were observed surrounding biomaterials particles of both groups and areas of bone formation were detected in close contact with biomaterials. All groups showed newly formed bone from the periphery to the center of the defects, which the control, HA and SrHA presented 36.4% (± 21.8), 31.2% (± 14.7) and 26.2% (± 12.9) of newly formed bone density, respectively, not presenting statistical differences. In addition, the connective tissue density did not show any significant between groups. The SrHA showing a higher volume density of biomaterial (51.2 ± 14.1) present in the defect compared to HA (32.6 ± 8.5) after 30 days (p = 0.03). Microspheres containing 1% SrHA or HA can be considered biocompatible, have osteoconductive properties and may be useful biomaterials for clinical applications.

Histomorphometric evaluation of strontium-containing nanostructured hydroxyapatite as bone substitute in sheep

Abstract The aim of this study is to evaluate the biocompatibility and osteoconductivity in surgical defects of sheep tibias filled with 1% strontium-containing nanostructured hydroxyapatite microspheres (SrHA), stoichiometric hydroxyapatite without strontium microspheres (HA), or blood clots. Santa Ines sheep were subjected to three perforations on the medial side of the left tibia. The biomaterials were characterized by X-ray Diffraction (XRD) and Fourier Transform Infrared (FTIR) before implantation and by X-Ray Microfluorescence (µFRX) and Scanning Electron Microscopy (SEM) after sheep tibias implantation. Surgical defects were filled with blood clots (control), SrHA (Group 1) or HA (Group 2). After 30 days, 5-µm bone blocks were obtained for histological evaluation, and the blocks obtained from 1 animal were embedded in methylmethacrylate for undecalcified sections. Mononuclear inflammatory infiltrate remained mild in all experimental groups. Giant cells were observed surrounding biomaterials particles of both groups and areas of bone formation were detected in close contact with biomaterials. All groups showed newly formed bone from the periphery to the center of the defects, which the control, HA and SrHA presented 36.4% (± 21.8), 31.2% (± 14.7) and 26.2% (± 12.9) of newly formed bone density, respectively, not presenting statistical differences. In addition, the connective tissue density did not show any significant between groups. The SrHA showing a higher volume density of biomaterial (51.2 ± 14.1) present in the defect compared to HA (32.6 ± 8.5) after 30 days (p = 0.03). Microspheres containing 1% SrHA or HA can be considered biocompatible, have osteoconductive properties and may be useful biomaterials for clinical applications.

Cytocompatibility and biocompatibility of nanostructured carbonated hydroxyapatite spheres for bone repair

ABSTRACT Objective The aim of this study was to investigate the in vitro and in vivo biological responses to nanostructured carbonated hydroxyapatite/calcium alginate (CHA) microspheres used for alveolar bone repair, compared to sintered hydroxyapatite (HA). Material and Methods The maxillary central incisors of 45 Wistar rats were extracted, and the dental sockets were filled with HA, CHA, and blood clot (control group) (n=5/period/group). After 7, 21 and 42 days, the samples of bone with the biomaterials were obtained for histological and histomorphometric analysis, and the plasma levels of RANKL and OPG were determined via immunoassay. Statistical analysis was performed by Two-Way ANOVA with post-hoc Tukey test at 95% level of significance. Results The CHA and HA microspheres were cytocompatible with both human and murine cells on an in vitro assay. Histological analysis showed the time-dependent increase of newly formed bone in control group characterized by an intense osteoblast activity. In HA and CHA groups, the presence of a slight granulation reaction around the spheres was observed after seven days, which was reduced by the 42nd day. A considerable amount of newly formed bone was observed surrounding the CHA spheres and the biomaterials particles at 42-day time point compared with HA. Histomorphometric analysis showed a significant increase of newly formed bone in CHA group compared with HA after 21 and 42 days from surgery, moreover, CHA showed almost 2-fold greater biosorption than HA at 42 days (two-way ANOVA, p<0.05) indicating greater biosorption. An increase in the RANKL/OPG ratio was observed in the CHA group on the 7th day. Conclusion CHA spheres were osteoconductive and presented earlier biosorption, inducing early increases in the levels of proteins involved in resorption.

Early osseointegration driven by the surface chemistry and wettability of dental implants.

OBJECTIVE: The objective of this study was to investigate the impact of two different commercially available dental implants on osseointegration. The surfaces were sandblasting and acid etching (Group 1) and sandblasting and acid etching, then maintained in an isotonic solution of 0.9% sodium chloride (Group 2). MATERIAL AND METHODS: X-ray photoelectron spectroscopy (XPS) was employed for surface chemistry analysis. Surface morphology and topography was investigated by scanning electron microscopy (SEM) and confocal microscopy (CM), respectively. Contact angle analysis (CAA) was employed for wetting evaluation. Bone-implant-contact (BIC) and bone area fraction occupied (BAFO) analysis were performed on thin sections (30 µm) 14 and 28 days after the installation of 10 implants from each group (n=20) in rabbits' tibias. Statistical analysis was performed by ANOVA at the 95% level of significance considering implantation time and implant surface as independent variables. RESULTS: Group 2 showed 3-fold less carbon on the surface and a markedly enhanced hydrophilicity compared to Group 1 but a similar surface roughness (p>0.05). BIC and BAFO levels in Group 2 at 14 days were similar to those in Group 1 at 28 days. After 28 days of installation, BIC and BAFO measurements of Group 2 were approximately 1.5-fold greater than in Group 1 (p<0.05). CONCLUSION: The surface chemistry and wettability implants of Group 2 accelerate osseointegration and increase the area of the bone-to-implant interface when compared to those of Group 1.

Early osseointegration driven by the surface chemistry and wettability of dental implants

Objective The objective of this study was to investigate the impact of two different commercially available dental implants on osseointegration. The surfaces were sandblasting and acid etching (Group 1) and sandblasting and acid etching, then maintained in an isotonic solution of 0.9% sodium chloride (Group 2). Material and Methods X-ray photoelectron spectroscopy (XPS) was employed for surface chemistry analysis. Surface morphology and topography was investigated by scanning electron microscopy (SEM) and confocal microscopy (CM), respectively. Contact angle analysis (CAA) was employed for wetting evaluation. Bone-implant-contact (BIC) and bone area fraction occupied (BAFO) analysis were performed on thin sections (30 μm) 14 and 28 days after the installation of 10 implants from each group (n=20) in rabbits' tibias. Statistical analysis was performed by ANOVA at the 95% level of significance considering implantation time and implant surface as independent variables. Results Group 2 showed 3-fold less carbon on the surface and a markedly enhanced hydrophilicity compared to Group 1 but a similar surface roughness (p>0.05). BIC and BAFO levels in Group 2 at 14 days were similar to those in Group 1 at 28 days. After 28 days of installation, BIC and BAFO measurements of Group 2 were approximately 1.5-fold greater than in Group 1 (p<0.05). Conclusion The surface chemistry and wettability implants of Group 2 accelerate osseointegration and increase the area of the bone-to-implant interface when compared to those of Group 1. .

Maxillary Sinus Augmentation with a New Xenograft: A Randomized Controlled Clinical Trial.

BACKGROUND: Insufficient residual alveolar bone height is a common deterrent in the placement of dental implants in the posterior maxilla. The use of autografts, xenografts, allografts and alloplasts or a combination between them has been demonstrated to be effective for increasing bone height and bone volume in the deficient posterior maxilla. PURPOSE: The aim of this clinical trial is to comparatively determine the density of newly formed in sinus floor augmentation bone after a 24-week healing period treatment with a new bovine xenograft. MATERIALS AND METHODS: The sinus floor was grafted with Bio-Oss® (n = 10) and Osseous® (n = 10). Histological sections were examined with a focus on the presence of connective tissue (CT) and newly formed bone (NFB). The sections were histomorphometrically evaluated and the definitive crown was inserted after 3 months. RESULTS: After 6 months, the mean value of new bone formation was 24.60 (±2.503), the CT was 42.60 (±4.006) and the remaining biomaterial was 25.40 (±2.547) in Bio-Oss group. In Osseous group, the mean value of new bone formation was 24.90 (±3.542), the CT was 45.70 (±7.040) and the remaining biomaterial was 22.90 (±3.247). CONCLUSIONS: Both biomaterials afforded a favorable implant position and the prosthetic rehabilitation.

Cytocompatibility and biocompatibility of nanostructured carbonated hydroxyapatite spheres for bone repair.

OBJECTIVE: The aim of this study was to investigate the in vitro and in vivo biological responses to nanostructured carbonated hydroxyapatite/calcium alginate (CHA) microspheres used for alveolar bone repair, compared to sintered hydroxyapatite (HA). MATERIAL AND METHODS: The maxillary central incisors of 45 Wistar rats were extracted, and the dental sockets were filled with HA, CHA, and blood clot (control group) (n=5/period/group). After 7, 21 and 42 days, the samples of bone with the biomaterials were obtained for histological and histomorphometric analysis, and the plasma levels of RANKL and OPG were determined via immunoassay. Statistical analysis was performed by Two-Way ANOVA with post-hoc Tukey test at 95% level of significance. RESULTS: The CHA and HA microspheres were cytocompatible with both human and murine cells on an in vitro assay. Histological analysis showed the time-dependent increase of newly formed bone in control group characterized by an intense osteoblast activity. In HA and CHA groups, the presence of a slight granulation reaction around the spheres was observed after seven days, which was reduced by the 42nd day. A considerable amount of newly formed bone was observed surrounding the CHA spheres and the biomaterials particles at 42-day time point compared with HA. Histomorphometric analysis showed a significant increase of newly formed bone in CHA group compared with HA after 21 and 42 days from surgery, moreover, CHA showed almost 2-fold greater biosorption than HA at 42 days (two-way ANOVA, p<0.05) indicating greater biosorption. An increase in the RANKL/OPG ratio was observed in the CHA group on the 7th day. CONCLUSION: CHA spheres were osteoconductive and presented earlier biosorption, inducing early increases in the levels of proteins involved in resorption.