The treatment of bone loss due to different etiologic factors is difficult, and many techniques aim to improve repair, including a wide range of biomaterials and, recently, photobioengineering. This work aimed to assess, through Raman spectroscopy, the level of bone mineralization using the intensities of the Raman peaks of both inorganic (∼ 960, ∼ 1,070, and ∼ 1,077 cm(-1)) and organic (∼ 1,454 and ∼ 1,666 cm(-1)) contents of bone tissue. Forty rats were divided into four groups each subdivided into two subgroups according to the time of killing (15 and 30 days). Surgical bone defects were made on femur of each animal with a trephine drill. On animals of group Clot, the defect was filled only by blood clot; on group Laser, the defect filled with the clot was further irradiated. On animals of groups Biomaterial and Laser + Biomaterial, the defect was filled by biomaterial and the last one was further irradiated (λ780 nm, 70 mW, Φ ∼ 0.4 cm(2), 20 J/cm(2) session, 140 J/cm(2) treatment) in four points around the defect at 48-h intervals and repeated for 2 weeks. At both 15th and 30th day following killing, samples were taken and analyzed by Raman spectroscopy. At the end of the experimental time, the intensities of both inorganic and organic contents were higher on group Laser + Biomaterial. It is concluded that the use of laser phototherapy associated to biomaterial was effective in improving bone healing on bone defects as a result of the increasing deposition of calcium hydroxyapatite measured by Raman spectroscopy.
Zirconia-reinforced lithium silicate (ZLS) is a ceramic that promises to have better mechanical properties than other materials with the same indications as well as improved adaptation and fracture strength. Objective In this study, marginal and internal misfit and fracture load with and without thermal-mechanical aging (TMA) of monolithic ZLS and lithium disilicate (LDS) crowns were evaluated.Material and methods Crowns were milled using a computer-aided design/computer-aided manufacturing system. Marginal gaps (MGs), absolute marginal discrepancy (AMD), axial gaps, and occlusal gaps were measured by X-ray microtomography (n=8). For fracture load testing, crowns were cemented in a universal abutment, and divided into four groups: ZLS without TMA, ZLS with TMA, LDS without TMA, and LDS with TMA (n=10). TMA groups were subjected to 10,000 thermal cycles (5-55°C) and 1,000,000 mechanical cycles (200 N, 3.8 Hz). All groups were subjected to compressive strength testing in a universal testing machine at a crosshead speed of 1 mm/min until failure. Student’s t-test was used to examine misfit, two-way analysis of variance was used to analyze fracture load, and Pearson’s correlation coefficients for misfit and fracture load were calculated (α=0.05). The materials were analyzed according to Weibull distribution, with 95% confidence intervals.Results Average MG (p<0.001) and AMD (p=0.003) values were greater in ZLS than in LDS crowns. TMA did not affect the fracture load of either material. However, fracture loads of ZLS crowns were lower than those of LDS crowns (p<0.001). Fracture load was moderately correlated with MG (r=-0.553) and AMD (r=-0.497). ZLS with TMA was least reliable, according to Weibull probability.Conclusion Within the limitations of this study, ZLS crowns had lower fracture load values and greater marginal misfit than did LDS crowns, although these values were within acceptable limits.
Aim: The aim of this study was to evaluate the surface roughness and the color stability of nanocomposite exposed to the sodium bicarbonate air-polishing (SBAP) followed by red wine, coffee and cigarette smoke exposure. Materials and Methods: 64 nanocomposite specimens were prepared and allocated in 8 groups: G1 (SBAP + distilled water), G2 (SBAP + coffee), G3 (SBAP + red wine), G4 (SBAP + cigarette smoke), G5 (distilled water), G6 (coffee), G7 (red wine) and G8 (cigarette smoke). The surface roughness was evaluated in three periods: before and after SBAP and after exposuring to agents tested. The color was evaluated according to CIEL*a*b* parameters using reflection spectrophotometer in two moments: initial and 30 days after the exposure to staining agents. Data were subjected to three-way repeated measures ANOVA and Tukey's test (5%). Results: The results showed a higher surface roughness of the nanocomposite submitted only to the SBAP and those exposed to the SBAP followed by exposure to the coffee or wine solution. The previous application of SBAP followed by cigarette smoke exposure did not increase the roughness of nanocomposite. The SBAP procedure just increased the staining for cigarette smoke group. Conclusion: The SBAP increases resin surface roughness, which worsens when there is exposure to coffee and red wine solution. In addition, SBAP may also provide increased staining of nanocomposites exposed to cigarette smoke.
ABSTRACT:This report aims to describe the clinical case of a 10-year-old male patient (R.C.B.C.), presenting nonsyndromic oligodontia with maternal family trait and absence of 22 permanent teeth. Clinically, the patient had prolonged retention of some primary teeth and presence of permanent maxillary left central incisor, permanent mandibular right central incisor and four first permanent molars. Radiographically, only permanent maxillary second molars and mandibular third molars were developing, whereas all other germs of permanent teeth were missing. Treatment consisted of maxillary expansion followed by moving permanent maxillary left central incisor bucco-mesially, and rehabilitation of spaces with removable denture, where the main goal was to restore function and esthetic harmony. The case has been monitored for the past six years. Nonsyndromic oligodontia is a rare condition that poses significant functional and psychosocial difficulties. Treatment usually requires a multidisciplinary approach among which pediatric dentistry and orthodontics play a major role. In view of its complexity, treatment should be initiated as early as possible to minimize future functional and aesthetic issues. Dental implants are considered as definitive treatment of cases of oligodontia, however, until the patient reached the ideal age, other treatments to ensure aesthetics and function must be performed.
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