Postoperative evaluation of Er:YAG laser, piezosurgery, and rotary systems used for osteotomy in mandibular third-molar extractions.

OBJECTIVE: This study compared patient postoperative pain, swelling, and trismus after usage of rotary instruments, piezosurgery, and Er:YAG lasers in mandibular third-molar extraction. MATERIALS AND METHODS: This prospective study was executed with class II and position B vertically impacted mandibular third molars. Patients were divided into three groups according to the osteotomy system used to remove retentive bone: rotary instruments, piezosurgery, and Er:YAG laser. Postoperative pain was evaluated using VAS questionnaires at 12 h, 24 h, 48 h, and 7 days after procedures. Trismus was evaluated by measuring the distance between the maxillary and mandibular incisors at maximum mouth opening, and comparing preoperative measurements with those for postoperative days 2 and 7. Analyses of swelling were carried out via a stereophotogrammetry system. Operation times were measured using a digital stopwatch from the initial incision to the final suture. RESULTS: There were no statistically significant differences between the groups in terms of pain, trismus, or swelling (p > 0.05). Pain persisted more in the rotary instrument group 24 h later (0 ± 1.3; p = 0.001). The pain scores obtained after 48 h for the piezosurgery (1.81 ± 2.29) and rotary (2.2 ± 2.12) groups were observed at 24 h in the laser group (2.19 ± 1.52). The mean operation time was highest using the laser (19.1 ± 3.85 min; p = 0.001) and lowest using rotary instruments (9.88 ± 2.97 min; p = 0.001). CONCLUSION: Piezosurgery and Er:YAG laser are good alternatives to rotary instrument systems in third-molar extraction, but both systems are slower than traditional rotary instruments.

Direct current electric stimulation in implant osseointegration: an experimental animal study with sheep.

In an effort to obtain a high-quality bone-implant interface, several methods involving alteration of surface morphological, physicochemical, and biochemical properties are being investigated. The aim of our study was to increase the osseointegration rate and quality and decrease the waiting period of dental implants before loading by using a microelectric implant stimulator device. It imitates microelectrical signals, which occur in bone fractures described in terms of piezoelectric theory. A single dental implant (Zimmer Dental), 3.7 mm in diameter, was inserted into the tibia of sheep bilaterally. Twenty-four dental implants were inserted into 12 sheep. Implant on the tibia of each sheep was stimulated with 7.5 µA direct current (DC), while the other side did not receive any stimulation and served as a control. Animals were sacrificed 1, 2, and 3 months after implantation. Bone segments with implants were processed with unclassified method. The determination of new bone formation and osseointegration around the dental implants was investigated by means of undecalcified method, histomorphologically. No statistically significant difference in bone-to-implant contact (BIC) ratio, osteoblastic activity, and new bone formation was found between the stimulation group and the control group at the late phase of healing (4, 8, and 12 weeks). No evidence was found that electric stimulation with implanted 7.5 µA DC is effective at late phase implant osseointegration on a sheep experimental model.

Effects of irrigation temperature on heat control in vitro at different drilling depths.

PURPOSE: Thermal injury during implant bed preparation has a major influence on implant osseointegration and survival. This study investigated the effectiveness of the temperature of the saline solution used for heat control during drilling. MATERIAL AND METHODS: Fresh frozen edentulous segments of bovine mandibles were sectioned into 12 x 6 cm pieces. Thermoresistors were placed 0.5 mm from the drilling cavity walls, at depths of 3, 7, and 12 mm. Signals from the three thermoresistors were analyzed using ORIGIN 5.0 software. RESULTS: The maximum temperatures during drilling without irrigation were 50.9, 47.4, and 38.1 degrees C at depths of 3, 7, and 12 mm, respectively. With irrigation using saline at 25 and 10 degrees C, the maximum temperatures at a depth of 12 mm were 37.4 and 36.3 degrees C, respectively. All other measurements with both 25 and 10 degrees C saline were below body temperature. DISCUSSION AND CONCLUSION: This experimental in vitro study showed that more heat was generated in the superficial part of the drilling cavity than at the bottom. Therefore, external irrigation at room temperature can provide sufficient cooling during drilling. Lower temperature saline was more effective in cooling the bone, and irrigation of the site should be continued between the drilling steps.

The influence of alendronate on bone formation after autogenous free bone grafting in rats.

OBJECTIVE: This study was undertaken to investigate the influence of alendronate on bone formation after autogenous free bone grafting in rats. STUDY DESIGN: Fifty-six male Wistar-Albino rats were divided into 3 groups: baseline, saline-treated, and alendronate-treated groups, and followed up at 2, 4, and 12 weeks. In the femur of the rats, autogenous free bone grafts 3 mm in diameter and 2 mm in length were harvested with a standard trephine bur. The bone defects 3 mm in diameter and 2 mm in length were created 5 mm from the donor sites. Each graft was placed in the bone defect and stabilized by perifemoral wiring. The alendronate-treated rats were administered 0.25 mg/kg alendronate subcutaneously daily. The saline-treated rats were given daily saline solution. Serum calcium, phosphate, parathyroid hormone, 1,25-dihydroxyvitamin D, bone alkaline phosphatase (BAP), osteocalcin, and urine calcium were measured. The changes in the number of osteoblasts bordering active bone formation surface and osteoid and lamellar bone formation were evaluated to measure anabolic bone activity. RESULTS: Alendronate caused significant increase in serum osteocalcin and BAP levels biochemically and the number of osteoblasts histopathologically. CONCLUSION: Alendronate may be considered among therapeutic options to improve bone formation process in different bone remodeling cases. Further detailed studies should be focused on dosage- and time-dependent effects of alendronate on bone formation.

Pediatric cervicofacial actinomycosis: a case report.

Cervicofacial actinomycosis affects many soft tissue and bony structures in the head and neck, and has both granulomatous and suppurative features. Pathogenesis of actinomycosis is still unclear, but trauma provides a portal of entry for the infection. It usually presents as a diffuse swelling with multiple sinus tracts containing macroscopic colonies of the organism known as "sulphur granules." Cervicofacial actinomycosis in children is rare. This article reports a case of actinomycosis in a 10-year-old-boy overlying the left ramus of the mandible.