Abstract Horizontal bone loss after tooth extraction is a common finding that demands bone reconstruction in various cases. The aim of this study was to assess the horizontal alveolar status in partially and completely edentulous patients using cone-beam computed tomography (CBCT). In total, 1516 CBCT scans of 1404 adult patients were analyzed. Assessment of the images was performed in accordance with the previously published horizontal alveolar change (HAC) classification, which categorizes horizontal bone defects into four classes: HAC 1, HAC 2, HAC 3 and HAC 4 (from the least severe to the most severe condition). Analysis of 1048 scans from partially edentulous patients presented a distribution of 63.55%, 22.14%, 13.36% and 0.95% in HAC 1, HAC 2, HAC 3 and HAC 4, respectively. Analysis of 468 scans from completely edentulous patient images presented a distribution of 19.87%, 28.63%, 41.67% and 9.83% in HAC 1, HAC 2, HAC 3 and HAC 4, respectively. Based on these results, as in HAC 4, no cancellous bone was found between the cortical buccal and lingual/palatal bone plates, it seems reasonable to state that the absence of cancellous bone is higher in completely edentulous patients than in partially edentulous patients. Therefore, the absence of cancellous bone seems to be higher in completely edentulous than in partially edentulous patients.

Abstract: The lack of guidelines for bone augmentation procedures might compromise decision making in implantology. The objective of this study was to perform a retrospective study to verify the outcomes of horizontal bone reconstruction in implant dentistry with different types of materials and amounts of native bone in the recipient bed to allow for a new guideline for horizontal bone reconstruction. One hundred preoperative CT scans were retrospectively evaluated and categorized in accordance to horizontal bone defects as presence (Group P) or absence (Group A) of cancellous bone in the recipient bed. Different approaches were used to treat the edentulous ridge and the outcomes were defined either as satisfactory or unsatisfactory regarding the possibility of implant placement. The percentage distribution of the patients according to the presence or absence of cancellous bone was 92% for Group P and 8% for Group A. In Group P, 98% of the patients had satisfactory outcomes, and the use of autografts had 100% of satisfactory outcomes in this group. In Group A, 37.5% of the patients had satisfactory outcomes, and the use of autografts also yielded 100% of satisfactory outcomes. The use of allografts and xenografts in Group A had 0% and 33.3% of satisfactory outcomes, respectively. Therefore, it seems reasonable to speculate that the presence of cancellous bone might be predictive and predictable when the decision includes bone substitutes. In cases of absence of cancellous bone in the recipient bed, the use of a vitalized graft seems to be mandatory.

PURPOSE: To evaluate the effects of the adipose-derived stem cells (ADSC) in the viability of random skin flap in rats.METHODS: Thirty five adult male Wistar rats (weight 250-300 g) were used. ADSC were isolated from adult male rats (n=5). ADSC were separated, cultured and then analyzed. A dorsal skin flap measuring 10x4 cm was raised and a plastic barrier was placed between the flap and its bed. After the surgical procedure, the animals were randomized into two groups (n=15 each group), group control and group ADSC. In all groups the procedures were performed immediately after the surgery. The percentage of flap necrosis was measured on the seventh postoperative day.RESULTS: The ADSC were able to replicate in our culture conditions. We also induced their adipogenic, osteogenic and chondrogenic differentiation, verifying their mesenchymal stem cells potentiality in vitro.The results were statistically significant showing that the ADSC decreased the area of necrosis (p<0.05).CONCLUSION:The cells demonstrated adipogenic, osteogenic and chondrogenic differentiation potential in vitro.The administration of adipose-derived stem cells was effective to increase the viability of the random skin flaps in rats.

PURPOSE: To propose an experimental burn model in NIH-3T3 cell line.METHODS:Induction of thermal injury in cultures of mouse fibroblast - NIH-3T3- cell line and determination of cell viability by MTT and imunofluorescence.RESULTS:The heating of the Petri dish increased proportionally to the temperature of the base and the time of exposure to microwave. In this in vitro burn model, using the cell line NIH-3T3 was observed drastic cellular injury with significant changes in cell viability and activity. It showed drastically modified cell morphology with altered membrane, cytoskeleton and nucleus, and low cellularity compared to the control group.CONCLUSION:The burn model in vitro using the cell line NIH-3T3 was reproductive and efficient. This burn model was possible to determine significant changes in cell activity and decreased viability, with drastic change in morphology, cell lysis and death.

PURPOSE: To evaluate the viability of random pattern dorsal skin flaps in rats after injection of adipose-derived stem cells (ADSC). METHODS: Thirty five adult male Wistar EPM rats (weight 250-300 g) were distributed, at random, in two groups. I- Control (flap elevation with injection of saline solution) with fifteen animals and II- Experimental (flap elevation with injection of ADSC ) with fifteen animal. The ADSC were isolated from others five adult male rats. A dorsal skin flap measuring 10x4 cm was raised and a plastic barrier was placed between the flap and its bed in both groups and the injection (cells or saline solution) were perfomed immediately after the surgery. The percentage of flap necrosis was measured on the seventh postoperative day. RESULTS: The ADSC were able to replicate in our culture conditions. We also induced their adipogenic, osteogenic and chondrogenic differentiation to verify their mesenchymal stem cells potentiality in vitro. The results were statistically significant showing that the ADSC decreased the area of necrosis (p<0.05). CONCLUSIONS: The cells demonstrated adipogenic, osteogenic and chondrogenic differentiation potential in vitro. The administration of adipose-derived stem cells was effective to increase the viability of the random random pattern dorsal skin flaps in rats.

PURPOSE: To evaluate the role of transforming growth factor beta 1 (TGF-β1) on the induced osteogenic differentiation of human dermal fibroblasts. METHODS: We performed four groups with cultured dermal fibroblasts according to the culture medium: CONTROL (DMEM culture medium); TGF-β1 (DMEM culture medium with 10 ng/ml of TGF-β1); OSTEOG (DMEM culture medium with 0.5 µg/ml of ascorbic acid, 10 mmol/l of β-glycerophosphate and 10 nmol/L of dexamethasone); and OSTEOG/TGF-β1 (osteogenic medium with 10 ng/ml of TGF-β1). Alkaline phosphatase (ALP) activity and the amount of osteocalcin (OC) in the supernatant, as well as the capability to form calcium phosphate deposits, were analysed for 28 days RESULTS: There were significant differences (p<0.05) between CONTROL and TGF-β1 groups in comparison with OSTEOG and OSTEOG/TGF-β1 groups in the ALP activity and OC amount. Although, both osteogenic groups had the same behavior with regard the expression curve during the experimental time, the OSTEOG/TGF-β1 group achieved significantly higher ALP and OC levels and showed no significant difference in the levels of mineralized deposits and in comparison with the levels found in the OSTEOG group. CONCLUSION: The addition of transforming growth factor beta 1 to the osteogenic culture medium increased the activity of alkaline phosphatase and the amount of osteocalcin, but TGF-β1 did not alter the presence of mineralized calcium phosphate deposits.

OBJETIVO: Avaliar os efeitos do estresse oxidativo e da suplementação do fator de crescimento de queratinócitos (KGF) em queratinócitos humanos cultivados. MÉTODOS: O estresse oxidativo foi produzido através da adição de peróxido de hidrogênio (H2O2) ao meio de cultura. Os queratinócitos humanos cultivados foram divididos em quatro grupos: grupo controle (G C), grupo KGF (G KGF), grupo H2O2 (G H2O2), grupo H2O2 e KGF (G H2O2-KGF). Cada experimento foi realizado com a mesma linhagem celular, em triplicata. A viabilidade celular foi avaliada pelo ensaio da exclusão do azul de tripan. RESULTADOS: Os resultados mostraram que o meio de cultura suplementado com o KGF apresentou menor taxa de viabilidade celular quando comparado às células do grupo controle (p<0,001). Isso mostra que somente o fator de crescimento de queratinócitos não apresentou efeito protetor às células em cultura. Entretanto, frente ao estresse oxidativo produzido pela adição do peróxido de hidrogênio ao meio de cultura, o KGF mostrou efeito benéfico, protegendo as células quando comparado ao grupo que sofreu a ação do estresse oxidativo, mas que não foi exposta ao KGF (p<0,001). CONCLUSÃO: O KGF determinou a proteção aos queratinócitos humanos primários cultivados expostos ao estresse oxidativo.

PURPOSE: To evaluate effects of oxidative stress and supplementation of keratinocyte growth factor (KGF) on cultivated human keratinocytes. METHODS: Oxidative stress was produced through addition of hydrogen peroxide (H2O2) to the culture medium. Cultivated human keratinocytes were divided in 4 groups: Group control (G C), Group KGF (G KGF), Group H2O2 (G H2O2), Group H2O2 and KGF (G H2O2-KGF). Each experiment was accomplished with the same lineage cultivated keratinocytes, in triplicate. Cell viability was evaluated by trypan blue exclusion assay. RESULTS: The results showed that the culture medium supplemented with KGF presented a small rate of cell viability when compared to cells only in culture medium (p<0,001). It demonstrated that only the growth factor does not have protector effects for cells in vitro. However, in front of the oxidative stress produced by addition of hydrogen peroxide to the medium, KGF showed a beneficial effect, protecting cells when compared to the group that suffered hydrogen peroxide action but had not been exposed to KGF (p<0,001). CONCLUSION: KGF determined protection to the primary human keratinocytes exposed to oxidative stress.