Effects of teriparatide on bone formation in rats with experimentally induced premaxillary expansion

ABSTRACT Objective: This study aimed to evaluate the effects of systemic teriparatide on sutural bone formation after premaxillary suture expansion in rats. Material and Methods: Twenty Wistar male rats (8-10 weeks old) were randomly divided into two groups, namely, control (C, n=10) and teriparatide (T, n=10). An expansion force was applied to the maxillary incisors using helical spring for a seven-day expansion period, for both groups. On the eighth day, the rats were kept for a seven-day consolidation period, and then 60 µg/kg teriparatide (once a day) was administered to group T subcutaneously for seven days. Then, all the rats were sacrificed, and histological sections were stained with hemotoxylin-eosin for examination. Anti-osteonectin, anti-osteocalcin, anti-Vascular endothelial growth factor (VEGF) and anti-transforming growth factor beta (TGF-β) were evaluated by immunohistochemical analysis in the midpalatal suture area. Results: Histologically, the newly formed bone tissue was observed to be larger in group T than in group C. The number of immunoreactive osteoblasts for osteonectin, osteocalcin and VEGF antibodies was significantly higher in group T than in group C (p = 0.0001). The TGF-β antibody showed a mild reaction in group T, but did not reach significance in comparison with group C (p ˃ 0.05). Conclusion: Systemic teriparatide application following the premaxillary expansion of the suture area may stimulate bone formation and add to the consolidation of the expansion in rats by regulating osteonectin, osteocalcin and VEGF.

RESUMO Objetivo: O presente estudo teve como objetivo avaliar os efeitos do uso sistêmico da teriparatida na formação óssea sutural após a expansão da pré-maxila em ratos. Material e Métodos: Vinte ratos machos da raça Wistar (com oito a dez semanas de vida) foram divididos aleatoriamente em dois grupos: controle (C, n=10) e teriparatida (T, n=10). Uma força de expansão foi aplicada aos incisivos superiores, usando uma mola helicoidal, por um período de expansão de sete dias em ambos os grupos. No oitavo dia, os ratos iniciaram um período de sete dias de consolidação, nos quais 60 µg/kg de teriparatida foram administrados (uma vez ao dia), por via subcutânea, para o grupo T. Posteriormente, todos os ratos foram sacrificados e cortes histológicos corados com hemotolixina-eosina foram examinados. Por meio de análise imuno-histoquímica da região da sutura palatina mediana, avaliou-se a presença de anti-ostenectina, anti-osteocalcina, anti-fator de crescimento endotelial vascular (VEGF) e anti- fator transformador de crescimento (TGF-β). Resultados: Histologicamente, observou-se que o tecido ósseo recém-formado foi maior no grupo T do que no grupo C. O número de osteoblastos imunorreativos para anticorpos de osteonectina, osteocalcina e VEGF foi significativamente maior no grupo T do que no grupo C (p = 0,0001). O anticorpo TGF-β mostrou uma pequena reação no grupo T; porém, sem diferença significativa para o grupo C (p ˃ 0,05). Conclusão: O uso sistêmico de teriparatida após a expansão da sutura na região da pré-maxila pode estimular a formação óssea e melhorar a consolidação da expansão em ratos, por meio da regulação de osteonectina, osteocalcina e VEGF.

Comparison of time-dependent two-dimensional and three-dimensional stability with micro-computerized tomography and wettability of three impression materials.

OBJECTIVES: The objective of this study is to explore time-dependent dimensional stability of three different elastomeric impression materials - vinyl polyether silicone (VPES), vinyl polysiloxane (VPS), and polyether (PE) - through micro-computerized tomography (µ-CT) imaging, allows three-dimensional (3D) imaging and measurement without sample preparation or chemical fixation. Materials and Methods: Thirty specimens were created using 3 mm high, 30 mm wide Teflon molds (n = 10). Specimens were scanned with µ-CT on the 1st (T1) h and 1st (T2), 7th (T3), and 14th (T4) days. 3D models were created at the above-mentioned times, volumetric measurements were conducted and dimensional changes were calculated. Diameters and heights of each impression material were measured with 2D analyses. Furthermore, contact angle measurements of these elastomeric impression materials were collected using the sessile drop method during and after polymerization at 0, 2, 5, 20, 60, 120, and 240 s These measurements were made on specimens (n = 10) prepared in standard sizes using a 50 µm deep stainless steel die with dimensions of 62 mm × 20 mm × 3 mm. RESULTS: Evaluation of the dimensional volume changes of the VPES, VPS, and PE measurements showed there to be no statistically significant differences between the T1, T2, T3, and T4 (P > 0.05). Only the decreases in the volume averages of T3 and T4 in the VPES were statistically significant (P < 0.05). As a result of binary comparisons, the evaluation of contact angle measurements of VPES, VPS, and PE materials during and after polymerization were compared. The average contact angle measurements of the VPS group were statistically significantly lower than the averages of the VPES and PE groups (P < 0.01). CONCLUSIONS: VPS was found to be the most stable impression material concerning dimensional change and wettability.

An evaluation of effects of platelet-rich-fibrin on postoperative morbidities after lower third molar surgery.

OBJECTIVES: The aim of the present study was to assess whether the use of platelet-rich fibrin (PRF) decreased the pain, swelling, and trismus levels of postoperative third molar surgery. MATERIALS AND METHODS: In a double-blinded, split-mouth randomized study, thirty patients (6 male/24 female, mean age 20.32 years) with bilateral symmetric impacted third molars were enrolled in this study to receive surgery. The PRF mass was randomly placed in one of the extraction sockets, whereas the other socket was left without treatment. The outcome variables were pain, maximum mouth opening (trismus), swelling (edema), and the presence of dry socket which were measured using a 10-point visual analog scale, manual calipers, and 3dMD facial imaging system which was used for the 1st time in the third molar surgery. RESULTS: Statistical analyses revealed that there were no significant differences between the control and study groups regarding postoperative pain, swelling, and trismus (P > 0.05). CONCLUSION: The results of this study suggest that PRF was not observed to have a positive effect on postoperative discomfort, so even though, PRF is presumed to have positive effects on healing and recovery processes.

Multivariate Analyses of Heavy Metals in Surface Soil Around an Organized Industrial Area in Eskisehir, Turkey.

A total of 50 surface industrial area soil in Eskisehir, Turkey were collected and the concentrations of As, Cr, Cd, Co, Cu, Ni, Pb, Zn, Fe and Mg, at 11.34, 95.8, 1.37, 15.28, 33.06, 143.65, 14.34, 78.79 mg/kg, 188.80% and 78.70%, respectively. The EF values for As, Cu, Pb and Zn at a number of sampling sites were found to be the highest among metals. Igeo-index results show that the study area is moderately polluted with respect to As, Cd, Ni. According to guideline values of Turkey Environmental Quality Standard for Soils, there is no problem for Pb, but the Cd values are fairly high. However, Cr, Cu, Ni and Zn values mostly exceed the limits. Cluster analyses suggested that soil the contaminator values are homogenous in those sub classes. The prevention and remediation of the heavy metal soil pollution should focus on these high-risk areas in the future.

Biocompatibility evaluation of orthodontic composite by real-time cell analysis.

INTRODUCTION: The aim of this study was to evaluate the cytotoxic effects of three different light-cured orthodontic composites. MATERIAL AND METHODS: Light Bond (Reliance orthodontic products), Grengloo (Ormco corporation), and Kurasper F (Kuraray Europe GmbH) were selected for the experiment. Specimens were prepared according to the manufacturers' instructions, measuring 5 mm in diameter and 2 mm in thickness. Fibroblast cells were obtained from healthy gingival connective tissues. The composite cylinders were incubated in Dulbecco's modified Eagle's culture medium for 72 h according to ISO 10993-5 standards. The xCELLigence method was used to evaluate fibroblast cell vitality. After seeding 200 mL of the cell suspensions into the wells (20,000 cells/well) of the E-plate 96, gingival fibroblasts were treated with bioactive components released by the orthodontic composite materials and monitored every 15 min for 121 h. RESULTS: There were no significant differences between the human gingival fibroblast (HGF) cell indexes of the control and all testing groups (p > 0.05) at 24 and 48 h. Light Bond demonstrated statistically significant decrease in HGF index (p < 0.05) at 72 h, but there was no significant difference among the Kurasper F, Grengloo, and untreated control groups (p > 0.05). Light Bond (p < 0.001) and Grengloo (p < 0.05) groups had lower HGF cell index values when compared to untreated control group, but Kurasper F demonstrated no significant differences between the control groups at 96 h (p > 0.05). CONCLUSION: Orthodontic composite materials include biologically active components and may change oral tissue. So, biocompatible orthodontic bonding composites should be used.

Does the timing and method of rapid maxillary expansion have an effect on the changes in nasal dimensions?

The aim of this study was to assess the effects of rapid maxillary expansion (RME) and surgical assisted rapid maxillary expansion (SARME) on nasopharyngeal area. The study group consisted of 30 subjects in the permanent dentition who had both maxillary constriction and a posterior cross-bite. The patients were divided into two groups, RME and SARME. The subjects in the RME group consisted of 15 patients (eight girls, seven boys) whose average age was 12.1 +/- 1.1 years. The SARME group also consisted of 15 patients (eight boys, seven girls) whose mean age was 18.4 +/- 1.4 years. An acrylic bonded RME appliance was used in both groups. Surgery was performed using lateral cortical osteotomies in the SARME group. The nasopharyngeal and respiratory area was determined using a digital planimeter on lateral cephalometric radiographs taken before and after RME. Nasal cavity width was evaluated on postero-anterior radiographs. Nasal dimension was measured using planimeter measurements of the respiratory and nasopharyngeal areas before and after treatment. The data obtained were analyzed using SPSS. Comparisons within the groups were carried out with paired t-tests and comparisons between the groups were with a Student's t-test. In both groups, the respiratory area and the ratio of the respiratory area to nasopharyngeal (RA/NA) area increased following RME. There were no statistically significant differences between the groups. Nasal cavity width and maxillary width also increased, but the difference between the groups was not significant. Following RME, various differences in both the maxilla and surrounding bones occurred and nasal width increased with a decrease in nasal airway resistance. At the end of treatment there were increases in the width of the nasal floor near the midpalatal suture and nasal cavity. As the maxillary structures separated, the outer walls of the nasal cavity moved laterally resulting in an increase in internasal volume. Nasal resistance decreased and respiratory area increased in patients treated with RME.