Effects of low-intensity pulsed ultrasound on healing of mandibular bone defects: an experimental study in rabbits.

Research evidence suggests that low-intensity pulsed ultrasound (LIPU) produces significant osteoinductive effects, accelerating the healing of bone defects. The authors investigated the effects of LIPU on mandibular bone defects in a rabbit model. Fifty-six adult Dutch rabbits were divided randomly into control, LIPU-1 (1MHz), and LIPU-3 (3MHz) groups. A mandibular defect was created in all rabbits. The effect of LIPU on mandibular defects was assessed by frequency (1 or 3MHz) and timing (2 and 4 weeks). Bone mineral density (BMD) was measured and stereology and histology performed; results were compared at the end of 2 and 4 weeks. LIPU-3 resulted in significantly higher bone formation compared to the control group at the end of week 4 on histological assessment (P=0.008). BMD was significantly higher at 4 weeks than at 2 weeks (P=0.03). LIPU-3 increased the numerical density of osteoblasts and osteocytes at the end of week 4 (P=0.05 and P=0.001, respectively). The results of this study are in favour of using LIPU 3MHz to accelerate mandibular bone healing. However, this study suggests that a frequency of 3MHz and the longer application of LIPU 3MHz for 4 weeks can only promote 8% mandibular bone healing in rabbits. Therefore, the use of LIPU has no really convincing, consistent clinical effects on maxillofacial bone healing.

Design and fabrication of helmholtz coils to study the effects of pulsed electromagnetic fields on the healing process in periodontitis: preliminary animal results.

BACKGROUND: Effects of electromagnetic fields on healing have been investigated for centuries. Substantial data indicate that exposure to electromagnetic field can lead to enhanced healing in both soft and hard tissues. Helmholtz coils are devices that generate pulsed electromagnetic fields (PEMF). Objective : In this work, a pair of Helmholtz coils for enhancing the healing process in periodontitis was designed and fabricated. METHOD: An identical pair of square Helmholtz coils generated the 50 Hz magnetic field.  This device was made up of two parallel coaxial circular coils (100 turns in each loop, wound in series) which were separated from each other by a distance equal to the radius of one coil (12.5 cm). The windings of our Helmholtz coil was made of standard 0.95mm wire to provide the maximum possible current. The coil was powered by a function generator.  RESULTS: The Helmholtz Coils generated a uniform magnetic field between its coils. The magnetic field strength at the center of the space between two coils was 97.6 µT. Preliminary biological studies performed on rats show that exposure of laboratory animals to pulsed electromagnetic fields enhanced the healing of periodontitis. CONCLUSION: Exposure to PEMFs can lead to stimulatory physiological effects on cells and tissues such as enhanced healing of periodontitis.

Comparative assessment of the therapeutic effects of the topical and systemic forms of Hypericum perforatum extract on induced oral mucositis in golden hamsters.

Oral mucositis is a common and irritating complication of chemotherapy and radiotherapy for malignancies. Current treatments have failed to achieve complete remission of this complication. The St. John's wort plant (Hypericum perforatum) has long been known for its anti-inflammatory and antibacterial effects. The current study was designed to investigate the therapeutic efficacy of the topical and systemic administration of H. perforatum extract on oral mucositis. Oral mucositis was induced in 72 male golden hamsters by administration of 5-fluorouracil (60mg/kg), on days 0, 5, and 10 of the study. The cheek pouch was scratched with a sterile needle on days 1 and 2. On days 12-17, H. perforatum extract topical gel 10%, oral H. perforatum extract (300mg/kg), and gel base groups were treated and then compared with a control group. Weights and blood samples were evaluated, biopsies from buccal lesions were examined histopathologically, and tissue malondialdehyde (MDA) was measured. Both of the H. perforatum extract treatment groups saw a significant relief in oral mucositis compared to the control and base gel groups; the systemic form was superior to the topical form. H. perforatum extract, administered orally or topically, expedited the healing of chemotherapy-induced oral mucositis in hamsters.

Effects of three Commercial Mouth Rinses on the Cultured Fibroblasts: An in Vitro Study.

STATEMENT OF PROBLEMS: An ideal antimicrobial agent should have minimal cytotoxic effect to host cells. PURPOSE: The aim of this study was to determine the cytotoxic effect of three commercial mouthwashes (Chlorhexidine, Persica and Irsha) on the cultured fibroblasts. MATERIAL AND METHODS: For determining the cytotoxic effect of Irsha, Chlorhexidine and Persica, uninfected cells were grown in the absence and presence of various concentration (2,4,8,16,32,64,128) of these mouth washes for 1, 2, 3 and 4 days. RESULTS: In this study, three mouth washes show cytotoxic effect on the cultured cells, at commercially available concentration and even diluted and Irsha was found to be the most toxic one. Cytotoxicity of three mouthwashes was reduced with decreasing concentration.

Serum level of matrix metalloproteinase-3 in patients with oral lichen planus.

BACKGROUND: Oral Lichen planus (OLP) is a chronic lesion of the oral mucosa with unknown origin. Basement membrane changes are common in OLP and may be mediated by proteases such as matrix metalloproteinase (MMPs) and mast cell chymase. The aim of our study was to evaluate the level of serum MMP-3 in OLP com-pared to normal individuals and assess its clinical significance. METHODS: Thirty four serum samples from patients diagnosed with OLP (12 males, 22 females, age: 42.2±10.8 years) and 34 serum samples from healthy control subjects (11 males, 23 females, age: 42.5±13.3 years) were collected and MMP-3 concentration was measured by ELISA. RESULTS: The serum MMP-3 level in OLP patients was higher (21.64±24.31 ng/ml) compared with healthy con-trols (16.52±23.63 ng/ml), but showed no statistically significant difference. A statistically significant difference was demonstrated between the two types of OLP, being more pronounced in the erosive/atrophic form 6). CONCLUSION: The different clinical appearances of OLP are associated with significant differences in MMP-3 serum level.

The prevalence of median rhomboid glossitis in diabetic patients: a case-control study.

BACKGROUND: Diabetes mellitus (DM) is one of the most common disorders of endocrine glands which has a worldwide distribution and is a risk factor for oral pathology so; the purpose of the present study was to investigate the association between median rhomboid glossitis (MRG) and DM. METHODS: We examined 202 Iranian patients with DM aged 10-86 years and 261 healthy subjects aged 10-28 years and the diagnosis of MRG was made based on clinical features. RESULTS: The examination indicated that 13 (6.43%) diabetic patients and 4 (1.53%) of control group had MRG.There was a significant difference in the prevalence of MRG, between patients and control group. MRG showed no association with other variables (age, sex, duration of DM, drugs, FBS, A1C). CONCLUSION: In the present study the prevalence of MRG in diabetics was much higher than that of controls.