The influence of low-level laser therapy with alendronate irrigation on healing of bone defects in rats.

The aim of this study was to investigate the effects of alendronate (Aln) irrigation with low-level laser therapy (LLLT) on the healing of bone defects in rats. Sixty Wistar rats weighing 250 to 300 g were randomly divided into three groups of 20 animals each: (1) control group, (2) Aln group, and (3) Aln with LLLT group. The distal epiphysis of all rats was perforated with a surgical bone drill. Twenty rats served as control. The bone defects of 40 rats received local alendronate sodium trihydrate irrigation (1 mg/ml) at the time of surgery. LLLT was applied to the bone defects of 20 rats immediately after Aln irrigation, and repeated on days 2, 4, 6, and 8 with a total dose of 10 J/cm(2) (2 J/cm(2) × 5). Continuous wave of GaAlAs laser (808 nm) was used with a power density of 0.1 W/cm(2). Laser energy was applied for 20 s (0.1 W × 20 s/1 cm(2)) per session. Control group, Aln group, and Aln with LLLT group rats were sacrificed at days 10 and 20 to compare the bone healing of each group histologically. There were significant differences between the three groups regarding union, substantia spongiosa, cortex formation, and in sum of histologic scores on days 10 and 20 (P < 0.0001). Our findings demonstrated that Aln has a more positive effect with LLLT on bone healing in rats. It was concluded that combining LLLT (808 nm laser at 10 J/cm(2)) with Aln irrigation has a beneficial effect in bone repair. It was demonstrated experimentally that Aln irrigation during the surgery had a significant effect to enhance bone formation, and LLLT significantly potentiated the osseous healing effects of Aln on bone defects. This administration method is able to minimize the dose of Aln in order to avoid both systemic and local adverse effects as well as the local injection times during the bone healing process.

A case of an extensive dentigerous cyst in the maxillary sinus leading to epiphora and nasal obstruction.

BACKGROUND: The dentigerous cyst is defined as a cyst that originates by the separation of the follicle from around the crown of an unerupted tooth. The clinical examination reveals a missing tooth or teeth and possibly a hard swelling, sometimes resulting in facial asymmetry and possible pathologic fracture. A large maxillary cyst involves the whole sinus and can transmit pressure to the walls of the sinus and, consequently, cause ophthalmologic and nasal symptoms to develop. OBJECTIVES: To report the case of an extensive dentigerous cyst with swelling of the right cheek, accompanied by unilateral nasal obstruction and epiphora. CASE REPORT: A 21-year-old man presented with swelling of the right cheek, right-sided nasal obstruction, and watering of the right eye. Panoramic radiography revealed a relatively large and well-defined radiolucency enveloping an unerupted maxillary canine tooth. Computed tomography scan showed a cystic lesion measuring 5.2 cm horizontally, 4.3 cm vertically, and 4 cm sagittally, with expansion and erosion of the anterosinus cortical bone. The mass was seen to extend into the right half of the nasal cavity up to the right ethmoid air cells, and was in contact with the base of the skull. The bony margins of the right maxillary antrum were thinned out, the osteomeatal complex was pushed medially-superiorly, and the pterygoid plates were intact. Excision of the dentigerous cyst of the right maxilla was performed using the Caldwell-Luc approach under general anesthesia. CONCLUSION: A dentigerous cyst arising from an unerupted tooth should be considered in the differential diagnosis of nasal obstruction, watering or epiphora of the eye, and fistula of the gingivobuccal sulcus.

Effect of biostimulation on healing of bone defects in diabetic rats.

BACKGROUND AND OBJECTIVE: The aim of this study was to investigate the effects of biostimulation on healing of bone defects in diabetic rats. STUDY DESIGN/MATERIAL AND METHODS: Twenty-eight Wistar rats weighting 250 to 300 g were used for this study. Diabetes was chemically induced with streptozotocin, and 14 nondiabetic and 14 diabetic rats were included in the study. The distal epiphysis of the right and left femurs of the diabetic rats were perforated with a surgical bone drill. This surgical procedure was performed on the left femurs of normal rats too. The wound on the right side of each diabetic rat received laser stimulation. The left femur of each nondiabetic (normal) rat served as a control. The rats were assigned to three experimental groups: (1) normal bur (control group); (2) diabetic bur; (3) diabetic bur + biostimulation. RESULTS: There was a significant difference among all groups in substantia spongiosa formation on day 10. According to the Mann-Whitney U test, there was a difference between Groups 1 and 2. A significant difference was noted between Groups 2 and 3 as well as between Groups 1 and 3 and between Groups 2 and 3 in union at 20 d of healing. CONCLUSIONS: Substantia spongiosa formation was slightly more evident in Groups 1 and 3 than in Group 2. Also, there was more union in Group 3 than in the other groups on day 20. As a result, it can be concluded that low-level laser therapy (808 nm laser at 10 J/cm(2)) can have a beneficial effect on spongiosa in diabetic bone repair when five treatments are administered with 2 d intervals between treatments.

Histologic evaluation of the effects of Er:YAG laser on bone ablation.

AIM: The aim of the present study was to compare the healing of bone defects created using an Er:YAG laser with those defects created using a surgical bone drill. METHODS AND MATERIALS: Fourteen Wistar rats were used for this study. Femurs were perforated with a surgical bone drill, coupled to a micromotor (bur group) to create a bone defect. Another defect was created using a 2940 nm wavelength Er:YAG laser on the same femur (Er:YAG Group). The Er:YAG laser was used with a energy density of 1.5 W in noncontact mode under a water coolant. Incisions were then sutured with polyglycolic acid sutures. Seven rats were sacrificed at day ten and the other seven at day 20 to compare the status of bone repair of each group at those post-surgical intervals. The femurs were fixed with 10% neutral buffered formalin and decalcified in 10% EDTA. The specimens were embedded in paraffin and sectioned at a 5 micron thickness and stained with hematoxylin and eosin (H&E) stain. The specimens were examined at a magnification of X100 and scored using a standardized histologic scoring system. RESULTS: Stages of bone healing including union, spongioza, cortex, and bone marrow development were evaluated and no significant difference between groups were found at days ten and 20 of healing. There was also no significant difference among the two groups in sum of histologic scores on day ten. CONCLUSION: Bone can be ablated effectively and precisely using a Er:YAG laser without the vibration associated with steel surgical burs, but it is a slower process than when burs are used. There was no significant difference between the two groups in terms of bone repair at ten and 20 day intervals of healing. CLINICAL SIGNIFICANCE: Within the limits of this study a 2940 nm Er:YAG laser at 1.5 W can be used with confidence in cases requiring effective bone ablation.

Effect of biostimulation on wound healing in diabetic rats.

BACKGROUND AND OBJECTIVE: Impaired wound healing is a complication of diabetes and is a serious problem in clinical practice. The purpose of this study was to evaluate the effect of biostimulation on wound healing in diabetic rats. MATERIAL AND METHODS: Thirty-six female Wistar rats weighting 250 to 300 g were used for this study. Diabetes was chemically induced with streptozotocin. Eighteen nondiabetic and 18 diabetic rats were included in the analysis. One incision was performed on the dorsum of each nondiabetic rat and the wound served as a control. Two parallel incisions were performed on the dorsum of each diabetic rat. The laser treatments were started immediately after surgery and were repeated on the second, fourth, sixth, and eighth days. A GaAlAs laser was used with an 808 nm wavelength. One wound of each diabetic rat received 10 J/cm(2) laser stimulation. RESULTS: Inflammation and re-epithelialization were evaluated in all groups, and there was a significant difference between the nondiabetic scalpel, diabetic scalpel, and diabetic scalpel + biostimulation groups. CONCLUSIONS: Treatment with laser biostimulation showed a beneficial effect on wound healing in diabetic rats. It can be concluded that low-level laser therapy (808 nm laser at 10 J/cm(2)) can have a beneficial effect on diabetic wound healing, when used at 2 d intervals over 5 d.