Abstract This study aimed to evaluate the effect of nicotine administration on the osseointegration of a superhydrophilic implants surface on rat tibiae. Thirty-two rats were used and divided into 2 groups according to the administration or not of nicotine: HH - Installation of implants with superhydrophilic surfaces in healthy animals; and HN - Installation of implants with superhydrophilic surfaces in animals subjected to nicotine administration. The animals were euthanized 15 and 45 days after implant placement (n = 8). Osseointegration was assessed by means of biomechanical analyses (removal torque), microcomputed tomography (volume of bone around the implants- %BV/TV), and histomorphometry (bone-implant contact -%BIC and the bone area between implant threads -%BBT). The animals subject to the nicotine administration presented lower removal torque than the control animals at the 45-day period (21.88 ± 2.80 Ncm vs. 17.88 ± 2.10 Ncm). The implants placed in the control rats presented higher %BIC (54.26 ± 6.59% vs. 39.25 ± 4.46%) and %BBT (50.57 ± 5.28% vs. 32.25 ± 5.24%) than the implants placed in nicotine animals at 15-day period. The nicotine administration reduces the osseointegration at 15 days, however, the superhydrophilic surface equalized the osseointegration in nicotine-exposed animals compared with healthy animals after 45 days of implant placement.

Resumo O objetivo deste estudo foi avaliar o efeito da administração de nicotina na osseointegração de implantes com superfície modificada por jateamento de oxidos e ataque ácido instalados em tíbia de ratos. Foram utilizados 32 ratos que foram divididos em 2 grupos de acordo com a administração ou não de nicotina: HH - Instalação de implantes com superfícies superhidrofílicas em animais sadios; e HN - Instalação de implantes com superfícies superhidrofílicas em animais submetidos à administração de nicotina. Os animais foram eutanasiados 15 e 45 dias após a colocação do implante (n = 8). A osseointegração foi avaliada por meio de análises biomecânicas (torque de remoção), microtomografia (volume de osso ao redor dos implantes - %BV/TV) e histomorfometrica (contato osso-implante -%BIC e área óssea entre roscas do implante -%BBT). Os animais submetidos à administração de nicotina apresentaram menor torque de remoção do que os animais controle no período de 45 dias (21,88 ± 2,80 Ncm vs. 17,88 ± 2,10 Ncm). Os implantes colocados nos ratos controle apresentaram maiores %BIC (54,26 ± 6,59% vs. 39,25 ± 4,46%) e %BBT (50,57 ± 5,28% vs. 32,25 ± 5,24%) do que os implantes colocados nos animais submetidos a administração de nicotina no período de 15 dias. A administração de nicotina prejudicou a osseointegração no período de 15 dias. Entretanto, a superfície superhidrofílica equalizou a osseointegração em animais expostos à nicotina em comparação com animais saudáveis após 45 dias da colocação do implante.

Abstract This study evaluated the effect of photobiomodulation therapy (PBMT) with a red or infrared laser on the repair of post extraction sockets in rats administered alendronate (ALN). Forty male rats were randomly allocated into four groups: Control Group (CTR): subcutaneous administration of saline solution throughout the experimental period; Alendronate Group (ALN): subcutaneous administration of alendronate during the entire experimental period; Alendronate/Red Laser Group (ALN/RL): administration of ALN and irradiation with a GaAlAs laser (λ 660 nm); and Alendronate/Infrared Laser Group (ALN/IRL): administration of ALN and irradiation with a GaAlAs laser (λ 830 nm). The first lower molars were extracted 60 days after the beginning of the administration of the drugs. The PBMT was applied after tooth extraction (7 sessions with intervals of 48 hours between sessions). Thirty days after tooth extraction, the animals were euthanized. Micro-CT and histometric analysis were performed to assess the bone healing and soft tissue repair of the tooth socket. The ALN group presented with more bone than the CTR; however, most of this bone was necrotic. ALN does not affect the bone microarchitecture. On the other hand, PBMT with IRL enhances the bone density due to the increase in the number and reduction in the spacing of the trabeculae. The amount of vital bone and connective tissue matrix was higher in the ALN/RL and ALN/IRL groups than in the ALN and CTR groups. PBMT enhanced the healing of the post extraction sockets in rats subjected to ALN administration. Furthermore, IRL improved the new bone microarchitecture.

Resumo O objetivo deste foi o de avaliar o efeito de uma superfície modificada por jateamento e ataque ácido e mantida em solução isotônica em comparação a uma superfície lisa sobre a osseointegração de implantes em animais hiperglicêmicos. No estudo foram utilizados 64 ratos, que foram divididos em 4 grupos com 16 animais em cada, e que foram avaliados em dois períodos experimentais (15 e 45 dias), com 8 animais em cada grupo. Os grupos foram divididos de acordo com o tipo de implante que foi instalado na tíbia dos animais e a condição sistêmica dos mesmos: Grupo CM - Implantes maquinados instalados em animais saudáveis; Grupo CH - Implantes maquinados instalados em animais com hiperglicemia; Grupo HM - Implantes hidrofílicos instalados em animais saudáveis, Grupo HH- Implantes hidrofílicos instalados em animais com hiperglicemia. Foram realizadas análises: biomecânicas (contra torque de remoção dos implantes), histométricas (avaliação do contato do osso com os implantes e da área de formação óssea entre as roscas) e microtomográfica (avaliação da área óssea ao redor dos implantes). Foi verificado que os implantes com superfície hidrofílica apresentaram maiores torques de remoção, quantidade de osso ao redor dos implantes e maiores valores de %BIC e %BBT em animais normo e hiperglicêmicos. Conclui-se que a superfície hidrofílica acelera o processo de osseointegração (~15% de %BIC/%BBT aos 15 dias), especialmente em animais com hiperglicêmicos. A superfície hidrofílica igualou a osseointegração entre animais normo- e hiperglicêmicos, revertendo o potencial negativo da hiperglicemia no processo de osseointegração.

Abstract The purpose of this study was to evaluate the effect of a surface modified by blasting and acid attack and maintained in an isotonic solution compared to a machined surface on osseointegration in normo- and hyperglycaemic animals. Sixty-four animals were allocated into 4 groups with 16 animals each, and they were subdivided into two experimental periods (15 and 45 days), with 8 animals in each group. The groups were divided according to the type of implant that was installed in the animals' tibia and the animals’ systemic condition: CM - Machined implants placed in Healthy animals; CH - Hydrophilic implants placed in Healthy animals, HM - Machined implants placed in animals with hyperglycaemia; HH- Hydrophilic implants installed in animals with hyperglycaemia. The following analyses were performed: biomechanical (removal torque), microtomographic (evaluation of the bone volume around the implants- BV/TV), and histomorphometric (evaluation of bone-implant contact BIC% and of the bone formation area between the threads BBT%). It was found that the implants with hydrophilic surfaces presented higher removal torques and quantities of BV/TV% and higher BIC% and BBT% values in normo- and hyperglycaemic animals. The results of this study indicated that the hydrophilic surface accelerates the osseointegration process (~ 15% BIC/BBT at 15-day period), especially in animals with hyperglycaemia. The hydrophilic surface equaled the osseointegration between normo- and hyperglycaemic animals, reversing the negative potential of hyperglycaemia on the osseointegration process.

Resumo Este estudo avaliou a osseointegração em áreas enxertadas com osso bovino desproteinizado (DBB) e cerâmica bifásica à base de hidroxiapatita e beta-fosfato tricálcico (HA / TCP) em tíbias de ratos. Defeitos ósseos não críticos foram feitos nas tíbias de 28 ratos que foram divididos aleatoriamente em 2 grupos: DBB: defeitos preenchidos com DBB e HA / TCP: defeitos preenchidos com HA / TCP. Defeitos ósseos foram confeccionados nas tíbias bilateralmente e preenchidos com biomateriais. Após 60 dias, os implantes foram instalados e os animais sacrificados 15 e 45 dias após a instalação dos implantes. A osseointegração foi avaliada por análises biomecânica, microtomográfica e histométrica. Os implantes instalados nos defeitos preenchidos com DBB apresentaram maiores forças de torque de remoção (2,33 ± 0,51 Ncm vs. 1,50 ± 0,54 Ncm) e volume de tecido mineralizado ao redor dos implantes aos 15 dias (34,96 ± 3,68% vs. 25,61 ± 2,95%) e maior contato osso-implante (20,87 ± 8,28% vs. 11,52 ± 7,42%) e área de osso dentro das roscas do implante (26,83 ± 12,35% vs. 11,98 ± 7,56%) no período de 45 dias em comparação com os implantes em áreas enxertadas com HA / TCP. Implantes instalados em áreas enxertadas com DBB apresentaram melhor padrão de osseointegração do que implantes colocados em áreas enxertadas com HA / TCP.

Abstract This study evaluated osseointegration in areas grafted with deproteinized bovine bone (DBB) and biphasic ceramic based on hydroxyapatite and beta-tricalcium phosphate (HA/TCP) in rat tibias. Noncritical bone defects were made in the tibias of 28 rats that were randomly assigned to 2 groups: DBB: DBB-filled defects and HA/TCP: HA/TCP-filled defects. Bone defects were made in the tibias bilaterally and filled with biomaterials. After 60 days, the implants were inserted, and the animals were euthanized 15 and 45 days after the implants were installed. Osseointegration was evaluated by biomechanical, microtomographic and histometric analysis. Implants installed in the defects filled with DBB presented higher removal torque forces (2.33 ± 0.51 Ncm vs. 1.50 ± 0.54 Ncm) and mineralized tissue volume around implants at 15 days (34.96 ± 3.68 % vs. 25.61 ± 2.95 %) and greater bone-implant contact (20.87 ± 8.28 % vs. 11.52 ± 7.42 %) and bone area within implant threads (26.83 ± 12.35 % vs. 11.98 ± 7.56 %) at 45 days compared to the measurements of implants in areas grafted with HA/TCP. Implants installed in defects in areas grafted with DBB had a better osseointegration pattern than implants placed in defects in areas grafted with HA/TCP.

Abstract Objective To evaluate the effect of different protocols of low-level intensity laser therapy (LLLT) irradiation on the osseointegration of implants placed in grafted areas. Methodology 84 rats were randomly allocated into six groups: DBB: defect filled with deproteinized bovine bone; HA/TCP: defect filled with biphasic ceramic of hydroxyapatite/β-tricalcium phosphate ; DBB-LI: defect filled with DBB and treated with LLLT after implant placement; HA/TCP-LI: defect filled with HA/TCP and treated with LLLT after implant placement; DBB-LIB: defect filled with DBB and treated with LLLT after graft procedure and implant placement; and HA/TCP-LIB: defect filled HA/TCP and treated with LLLT after graft procedure and implant placement. The bone defects were made in the tibia and they were grafted. After 60 days, the implants were placed. The rats were subsequently subjected to euthanasia 15 and 45 days after implant placement. The pattern of osseointegration and bone repair in the grafted area was evaluated by biomechanical, microtomographic, and histometric analyses. Furthermore, the expression of bone biomarker proteins was assessed. Results The LLLT groups presented higher removal torque, mineralized tissue volume, and a greater degree of osseointegration, especially when LLLT was performed only after implant placement, and these findings were associated with higher expression of BMP2 and alkaline phosphatase. Conclusion LLLT performed on implants placed in grafted areas enhances the osseointegration process.

Abstract There are several studies that evaluate the use of lasers in periodontal treatment in non-surgical or surgical therapy. However, while several studies showed clinically beneficial effects of some lasers in periodontal treatment, there are few clinical reports of additional advantages of lasers as adjunctive treatments in periodontology. The aim of this paper is to demonstrate and critically analyze the level of scientific evidence of effects of low-level lasers and high-power lasers in periodontology. A narrative review of the studies was carried out in each topic and type of laser or periodontal treatment. In nonsurgical periodontal therapy the results showed that there is an additional clinical benefit when using a diode laser (DL) associated with scaling and root planing (SRP) in patients with moderate to severe periodontitis. The Er:YAG laser seems to be the most suitable for nonsurgical periodontal therapy and promotes the same clinical effects as conventional therapy. In periodontal surgery vaporization of the gingival or mucosal tissue can be carried out with DL, CO2, Nd:YAG, Er:YAG and Er,Cr:YSGG lasers. Photobiomodulation (PBM), mediated by low-level lasers associated with non-surgical periodontal therapy, promotes additional benefits in the short term and accelerates the bone and gingival tissue repair process and also reduces postoperative symptoms of periodontal surgery. The effect of antimicrobial Photodynamic Therapy is relevant in the initial reevaluation periods. Studies have shown controversial results of the use of lasers in periodontics, and this fact may be due to the lack of standard parameters of irradiation in each clinical application.

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.

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.

Abstract Objective: This study aimed to evaluate the effect of avocado/soybean unsaponifiables (ASU) on periodontal repair in rats with induced periodontitis and arthritis. Methodology: Forty-five rats were submitted to periodontitis induction by insertion of ligatures into the upper second molars, maintained for 15 days. These animals were randomly allocated to 3 groups according to the presence of induced arthritis (ART) and the application of the ASU: Control (CTR) group-healthy animals, where saline solution was administered; ART-animals with induced arthritis, where saline solution was administered; ART/ASU-animals with induced arthritis, where ASU (0.6 mg/ kg) was administered. The drugs were administered daily by gavage and the animals were euthanized after 7, 15 and 30 days of the ligature removal. Bone resorption, inflammatory infiltrate composition and marker proteins expression of the differentiation and formation of osteoclasts (RANKL and TRAP) were assessed. Results: The ART/ASU group presented higher bone volume than the ART group at 7 and 30 days after the ligature removal. Furthermore, the ART group presented higher quantity of inflammatory cells and expression of TRAP and RANKL than the other groups. Conclusion: ASU administration improves the repair of periodontal tissues in an experimental periodontitis model in rats with induced arthritis.

Resumo Introdução A utilização de substitutos ósseos em procedimentos de enxertia de forma alternativa ao uso do osso autógeno tem sido indicada, entretanto a comparação direta entre esses biomateriais tem sido pouco explorada. Objetivo Avaliar o efeito de diferentes biomateriais osteocondutores sobre o reparo de defeitos críticos em calvárias (DCC) de ratos. Material e método Foram utilizados 40 ratos que foram submetidos a confecção de um DCC com 8 mm de diâmetro. Os animais foram aleatoriamente divididos em 5 grupos com 8 animais, de acordo com o tipo de biomaterial utilizado para preencher os DCC: Grupo COA (coágulo); Grupo AUT (osso autógeno); Grupo OBD (osso bovino desproteinizado); Grupo HA/ TCP (cerâmica bifásica composta de hidroxiapatita e β fosfato tricálcio); Grupo TCP (β fosfato tricálcio). Foram executadas análise microtomográfica para avaliação do comprimento linear remanescente (DLL) do DCC e o volume dos tecidos mineralizados (MT) dentro do DCC nos períodos de 3, 7, 15 e 30 dias após cirurgia. Adicionalmente, foi executado análise histométrica para avaliar a composição do tecido ósseo reparado (% Osso e % Biomaterial) no período de 30 dias. Resultado O grupo COA apresentou o menor DLL e MT dentro do DCC e maior % osso do que os outros grupos. O grupo OBD apresentou maior volume de tecidos mineralizados e maior % biomaterial do que o grupo os grupos AUT e TCP. Os grupos OBD e AUT apresentaram maior % osso que o grupo TCP. Conclusão O OBD promoveu melhor padrão de aumento de disponibilidade óssea e qualidade do osso reparado em comparação ao TCP e HA/TCP, porém biologicamente inferior ao grupo AUT.

Abstract Introduction The use of bone substitutes in grafting procedures as an alternative of the use of autogenous bone graft has been indicated, however, the direct comparison between these biomaterials has been little explored. Objective To evaluate the effect of different osteoconductive bone substitutes on the bone repair in critical-sized defects (CSDs) in rat calvaria. Material and method One CSD with an 8 mm diameter was made in each of the 40 rats used in this study. The animals were randomly allocated into 5 groups (n=8), according to the type of bone substitute used to fill the CSD: COA (Coagulum); AUT (autogenous bone); DBB (deproteinized bovine bone graft); HA/TCP (biphasic ceramic composed of hydroxyapatite and β-phosphate tricalcium); and TCP (β-phosphate tricalcium). A microtomographic analysis was performed to evaluate the remaining defect linear length (DLL) of the CSD and the volume of the mineralized tissues (MT) within the CSD at 3, 7, 15 and 30 days after the surgical procedure. In addition, a histometric analysis was performed to evaluate the composition of the repaired bone tissue (% Bone and % Biomaterial) at the 30-day period. Result It was shown that the COA had the lowest DLL and MT within the CSD. In addition, the COA presented the highest % of bone in CSD. The DBB had a higher MT and a higher % of bone substitute particles in the CSD than the AUT and TCP groups. The DBB and AUT groups presented higher % of bone in the CSD than the TCP group. Conclusion The use of the DBB promoted a better pattern of bone volume gain and formation compared to TCP and HA / TCP but was biologically inferior to the AUT.

Abstract The purpose of this study is to evaluate the effect of the avocado/soybean unsaponifiables (ASU) on the treatment of induced periodontitis in rats. Periodontitis was induced in 84 rats via ligature placement around the second upper molar, which was removed after 7 days, and scaling and root planning (SRP) was performed at this time. Subsequently, the rats were randomly allocated to four groups with 21 animals each: One SRP group in which saline solution was administered (SS), and three groups in which ASU was administered (0.6 g/kg/day), beginning either 7 days before the induction of periodontitis (SRP/ASU-7), on the day of periodontitis induction (SRP/ASU0), or on the day of treatment (SRP/ASU+7). ASU and SS were administered daily by gavage until the sacrifice of the animals (7, 15, and 30 days after SRP). The % bone in the furcation area was evaluated by histomorphometry and micro-CT. The expression of proteins (TRAP, RANKL, and alkaline phosphatase) and mRNA (IL-1β, TNF-α, IL-6, RANKL, and alkaline phosphatase) were evaluated by immunohistochemistry and qPCR. The SRP/ASU+7 group presented a higher percentage of bone fill in the furcation area and higher expression of alkaline phosphatase than in the SRP group (at 7 and 30 days, respectively). The SRP/ASU0 and SRP/ASU+7 groups presented lower expression levels of RANKL mRNA than the SRP and SRP/ASU-7 groups at 15 days. ASU administration on the day of the SRP treatment of the ligature-induced periodontitis promoted subtle beneficial effects on periodontal repair following the treatment of induced periodontitis within the experimental period of 7 days.

OBJETIVO: Avaliar histomorfometricamente o efeito de biovidro (B), osso bovino liofilizado (OB) ou da mistura desses dois biomateriais (B/OB - 1:1) no reparo de defeitos ósseos críticos em calvária de ratos. MATERIAL E MÉTODO: Defeitos ósseos (8 mm Ø) foram criados cirurgicamente na calvária de 24 ratos, distribuídos em 4 grupos com 6 animais, de acordo com o tipo de biomaterial: coágulo sanguíneo (GC), biovidro (GB), osso bovino liofilizado (GOB) e a mistura desses dois biomateriais (GB/OB). Os animais foram eutanasiados após 15 e 60 dias do procedimento cirúrgico (3 animais por período). A avaliação histológica foi baseada na descrição da morfologia dos tecidos neoformados, enquanto para a avaliação histomorfométrica foi realizada quantificação da porcentagem de tecido ósseo, de tecido conjuntivo fibroso neoformados e de biomaterial remanescente no defeito ósseo. RESULTADO: Nos dois períodos experimentais, a análise histológica apresentou neoformação óssea, principalmente nas bordas dos defeitos, e ao redor de partículas de biomateriais remanescentes. A avaliação histomorfométrica demonstrou que no período de 15 dias o grupo GC apresentou maior percentagem de tecido ósseo em relação aos demais grupos estudados, enquanto que aos 60 dias o grupo GOB apresentou maior porcentagem de tecido ósseo em relação ao grupo GB. CONCLUSÃO: O osso bovino liofilizado apresentou maior formação óssea em relação ao biovidro, mas nenhum dos biomateriais foi superior ao coágulo. A associação do biovidro e osso bovino liofilizado não adicionou vantagem à formação óssea.

OBJECTIVE: This study sought to histomorphometrically evaluate the effect of bioglass (B), lyophilized bovine bone (BB) or the 1:1 mixture of these two biomaterials on the repair of critical bone defects in rat calvaria. MATERIAL AND METHOD: Bone defects (8 mm Ø) were surgically created in the calvaria of 24 rats, which were divided into the following 4 groups of 6 animals each according to the type of biomaterial used: blood clot / coagulum (control) group (CG), bioglass group (BG), lyophilized bovine bone group (BBG) and a group receiving a mixture of these two biomaterials (BG/BB). The animals were euthanized at 15 or 60 days after surgery (3 animals per period). Histological evaluation was based on the morphological description of the newly formed tissues, and a quantification of the percentage of bone tissue with newly formed fibrous connective tissue and the percentage of biomaterial remaining in the bone defect was performed for the histomorphometric evaluation. RESULT: In both experimental periods, the histological analysis showed new bone formation, especially at the edges of the defects and around remaining biomaterial particles. Histomorphometric analysis showed that the CG contained a higher percentage of bone tissue over the 15-day period compared to that of the other groups. At 60 days, the BBG showed a higher percentage of bone tissue compared to that of the BG (p <0.01). CONCLUSION: Lyophilized bovine bone led to greater bone formation compared to bioglass, but none of the biomaterials was superior to blood clot. Moreover, the combination of bioglass and lyophilized bovine bone did not provide an advantage for bone formation.

The posterior position in the arches is one of the factors that underlies the poor prognosis of molar teeth (M). It is speculated that M do not benefit from the oral hygiene routine as well as non-molars (NM) do. This study evaluated the response of M and NM to supragingival control during a 6-month period in 25 smokers (S) and 25 never-smokers (NS) with moderate-to-severe periodontitis. One calibrated examiner assessed visible plaque (VPI) and gingival bleeding (GBI) indexes, periodontal probing depth (PPD), bleeding on probing (BOP), and clinical attachment loss (CAL) at days 0 (baseline), 30 and 180. At baseline, M showed significantly higher mean values of VPI (p = 0.017) and PPD (p < 0.001) compared with NM; CAL was also greater in M (p < 0.001) and was affected by smoking (p = 0.007). The reductions obtained for periodontal indicators at day 180 showed similar responses between M and NM. For CAL, M (NS 0.57 ± 0.50; S 0.67 ± 0.64) and NM (NS 0.38 ± 0.23; S 0.50 ± 0.33) reached an almost significant difference (p = 0.05). Smoking did not influence the response to treatment. Multilevel analysis revealed that, only for PDD reductions, the interaction between sites, teeth and patient was significant (p < 0.001). It was concluded that M benefit from an adequate regimen of supragingival biofilm control; therefore, supragingival condition should be considered in the prognosis of molar teeth.

OBJETIVO: Este estudo avaliou através de imagens radiográficas digitais, a ação de biomateriais de quitosana e de cloridrato de quitosana, com baixo e alto peso molecular, utilizados na correção de defeitos ósseos de tamanho crítico (DOTC)em calvária de ratos. MATERIAL E MÉTODO: DOTCs com 8 mm de diâmetro foram criados cirurgicamente na calvária de 50 ratos Holtzman. Em 10 animais o defeito foi preenchido foram preenchidos com coágulo sanguíneo (controle negativo). Os 40 animais restantes foram divididos de acordo com o biomaterial utilizado no preenchimento do defeito (quitosana de baixo peso e de alto peso molecular, e cloridrato de quitosana de baixo e de alto peso molecular), e foram avaliados em dois períodos experimentais (15 e 60 dias), totalizando 5 animais/biomaterial/período de avaliação. RESULTADO: A avaliação radiográfica foi feita utilizando duas radiografias digitais do crânio do animal: uma tomada logo após o defeito ósseo ser criado e a outra no momento do sacrifício. Nessas imagens, foi avaliada a densidade óssea radiográfica inicial e a final na área do defeito, que foram comparadas. As análises na densidade óssea radiográfica indicaram aumento da densidade óssea radiográfica dos DOTCs tratados para todos os biomateriais testados, em ambos os períodos. Resultados semelhantes foram encontrados no grupo controle. CONCLUSÃO: Conclui-se que os biomateriais de quitosana testados não foram capazes de aumentar a densidade radiográfica em DOTC realizados em calvária de ratos.

OBJECTIVE: This study evaluated, using digital radiographic images, the action of chitosan and chitosan hydrochloride biomaterials, with both low and high molecular weight, used in the correction of critical-size bone defects (CSBD's) in rat's calvaria. MATERIAL AND METHOD: CSBD's with 8 mm in diameter were surgically created in the calvaria of 50 Holtzman rats and these were filled with a blood clot (Control), low molecular weight chitosan, high molecular weight chitosan, low molecular weight chitosan hydrochloride and high molecular weight chitosan hydrochloride, for a total of 10 animals, which were divided into two experimental periods (15 and 60 days), for each biomaterial. The radiographic evaluation was made using two digital radiographs of the animal's skull: one taken right after the bone defect was created and the other at the moment of the sacrifice, providing the initial and the final radiographic bone density in the area of the defect, which were compared. RESULT: Analysis of radiographic bone density indicated that the increase in the radiographic bone density of the CSBD's treated with the proposed biomaterials, in either molecular weight, in both observed periods, where similar to those found in control group. CONCLUSION: Tested chitosan-based biomaterials were not able to enhance the radiographic density in the CSBD's made in rat's calvaria.