Manoel Sant'Ana Filho

Comparative histological analysis of bone healing of standardized bone defects performed with the Er:YAG laser and steel burs

This study compares the bone repair process after ostectomies performed either with the erbium:yttrium-aluminum-garnet (Er:YAG) laser or with the low-speed bur drilling. Eighteen rats were used for this study. In the control group, the ostectomy was performed with a low-speed bur drilling. In the experimental group, the ostectomy was made with an Er:YAG laser (500xa0mJ, 10xa0Hz). At 7 and 14xa0days after surgery, the experimental group presented earlier bone repair in comparison to the control group. The experimental group presented an altered layer of approximately 24-μm thickness, whereas the control group did not present any altered layer in the margins of the ostectomies. At 21xa0days, the histological features of the two groups were very similar, although the altered layer could still be seen. The Er:YAG laser successfully promoted the ablation of the bone tissue, but caused some thermal damage at the margins of the ostectomies.

Bone tissue microscopic findings related to the use of diode laser (830etam) in ovine mandible submitted to distraction osteogenesis

PURPOSEnTo analyze the microscopic characteristics of the effect of Gallium-Aluminum Arsenid diode laser (GaAlAs - 830etam) applied during the activation and consolidation period to ovine mandibles submitted to distraction osteogenesis.nnnMETHODSnEighteen sheep underwent surgery in order to have bone distractors implanted in the left side of the jaw area. They were divided into three groups: 1 - Control; 2 - Laser irradiation during the activation period; 3 - Laser irradiation during the fixation period. The irradiation was carried out in five sessions, on every other day, with 4,0J/cm(2) doses applied to four pre-established areas, totaling 16J per session. After four days of latency under post-operative care, ten days of distractor activation (at 1mm/day) and twenty-one days of fixation the animals were sacrificed and the devices removed for microscopic analysis.nnnRESULTSnThe groups that received laser irradiation (GaAlAs) presented a greater amount of mineralized bone trabeculae when compared to the Control Group. Despite that, cartilaginous tissues were also found in Group 2.nnnCONCLUSIONnThe laser has been more favorable when used in the consolidation period, after bone elongation.

Calcitonin: A non-invasive giant cells therapy

This paper reports four cases of central giant cell granuloma (CGCG) treated with calcitonin, attesting the efficacy and safety of its use as the chosen therapy for large CGCG. Four patients presenting CGCG treated with calcitonin were included in this study. Salmon calcitonin was administered for 6-28 months. It was observed determination of clear lesion limits for surgery, reduction and limitation of lesions. In aggressive cases, the calcitonin therapy was an excellent option, since it does not harm the patient, and a far less aggressive, complementary surgery may be performed in certain cases, avoiding life-long sequelae.

Comparative histomorphometric analysis between α-Tcp cement and β-Tcp/Ha granules in the bone repair of rat calvaria

This study compared the effect of two bioceramics on the process of bone repair: α-tricalcium phosphate (α-TCP) cement and β-tricalcium phosphate hydroxyapatite particles (β-TCP/HA). Calvarial defects were created in 50 rats, divided into two groups (α and β/HA). Software was used at 7, 21, 60, 90 and 120 days to assess bone formation. Mean new bone formation rates were as follows: α group, 1.6% at 7 days, 5.24% at 21 days, 24% at 60 days, 30.21% at 90 days and 50.59% at 120 days; β/HA group, 1.94% at 7 days, 2.53% at 21 days, 12.47% at 60 days, 26.84% at 90 days and 38.82% at 120 days; control group, 0.15% at 7 days, 10.12% at 21 days, 15.10% at 60 days, 18.94% at 90 days, 48.50% at 120 days. Both materials are osteoconductive and biocompatible. Perhaps the larger rate of new bone formation observed in the α-TCP group, it also occurs in the β-TCP/HA group within a longer time period.