Bone union formation in the rat mandibular symphysis using hydroxyapatite with or without simvastatin: effects on healthy, diabetic, and osteoporotic rats.

OBJECTIVE: The objective is to compare new bone formation in critical defects in healthy, diabetic, and osteoporotic rats filled with hydroxyapatite (HA) alone and HA combined with simvastatin (SV). MATERIALS AND METHODS: A total of 48 adult female Sprague-Dawley rats were randomized into three groups (n = 16 per group): Group, 1 healthy; Group 2, diabetics; and Group 3, osteoporotics. Streptozotocin was used to induce type 1 diabetes in Group 2, while bilateral ovariectomy was used to induce osteoporosis in Group 3. The central portion of the rat mandibular symphysis was used as a physiological critical bone defect. In each group, eight defects were filled with HA alone and eight with HA combined with SV. The animals were sacrificed at 4 and 8 weeks, and the mandibles were processed for micro-computed tomography to analyze radiological union and bone mineral density (BMD); histological analysis of the bone union; and immunohistochemical analysis, which included immunoreactivity of vascular endothelial growth factor (VEGF) and bone morphogenetic protein 2 (BMP-2). RESULTS: In all groups (healthy, diabetics, and osteoporotics), the defects filled with HA + SV presented greater radiological bone union, BMD, histological bone union, and more VEGF and BMP-2 positivity, in comparison with bone defects treated with HA alone. CONCLUSIONS: Combined application of HA and SV improves bone regeneration in mandibular critical bone defects compared with application of HA alone in healthy, diabetic, and osteoporotic rats. CLINICAL RELEVANCE: This study might help to patients with osteoporosis or uncontrolled diabetes type 1, but future studies should be done.

Effects of photodynamic therapy, 2 % chlorhexidine, triantibiotic mixture, propolis and ozone on root canals experimentally infected with Enterococcus faecalis: an in vitro study.

The aim of this study was to evaluate the antibacterial effect of photodynamic therapy (PDT), 2 % chlorhexidine (CHX). The teeth were contaminated with 0.1 mL Enterococcus faecalis (3 × 108 cell/mL) and randomized into eight treatment groups: Group 1 (2.5 % NaOCl); Group 2 (PDT); Group 3 (2 % CHX); Group 4 (TAM); Group 5 (propolis), Group 6 (ozone), Group 7 (positive control) and Group 8 (negative control). Following treatment, the canal content was sampled. The samples were cultured in triplicate on blood agar plates to determine the number of colony forming units (CFU)/mL. The teeth were analyzed by SEM to determine the percentage of area with contamination and debris. The group with the lowest CFU/mL count was the ozone group, which obtained similar values to the PDT group. SEM images showed that 2.5 % NaOCL group showed the lowest percentage of contaminated area. Applications of PDT, 2 % CHX, TAM, propolis and ozone showed antibacterial potential similar to 2.5 % NaOCL.

Chemical genoprotection: reducing biological damage to as low as reasonably achievable levels.

OBJECTIVES: The aim of this study was to evaluate the antioxidant substances present in the human diet with an antimutagenic protective capacity against genotoxic damage induced by exposure to X-rays in an attempt to reduce biological damage to as low a level as reasonably possible. METHODS: Ten compounds were assessed using the lymphocyte cytokinesis-block micronucleus (MN) cytome test. The compounds studied were added to human blood at 25 µM 5 min before exposure to irradiation by 2 Gy of X-rays. RESULTS: The protective capacity of the antioxidant substances assessed was from highest to lowest according to the frequency of the MN generated by X-ray exposure: rosmarinic acid = carnosic acid = δ-tocopherol = l-acid ascorbic = apigenin = amifostine (P < 0.001) > green tea extract = diosmine = rutin = dimetylsulfoxide (P < 0.05) > irradiated control. The reduction in genotoxic damage with the radiation doses administered reached 58%, which represents a significant reduction in X-ray-induced chromosomal damage (P < 0.001). This degree of protection is greater than that obtained with amifostine, a radioprotective compound used in radiotherapy and which is characterised by its high toxicity. CONCLUSION: Several antioxidant substances, common components of the human diet and lacking toxicity, offer protection from the biological harm induced by ionizing radiation. Administering these protective substances to patients before radiological exploration should be considered, even in the case of small radiation doses and regardless of the biological damage expected.

Is it true that the radiation dose to which patients are exposed has decreased with modern radiographic films?

OBJECTIVES: To determine whether the radiation dose administered to patients has decreased with new radiographic films and digital imaging systems. METHODS: A total of 10 171 official reports on radiological practice in dental surgeries (covering the years 1996-2003) from 16 Spanish autonomous regions were studied, analysing the type of film used, the exposure times and the radiation doses administered in each dental clinic for four different teeth: upper molar, lower molar, upper incisor and lower incisor. RESULTS: The Agfa Dentus M2 radiographic film needed the longest exposure times for all of the teeth (0.6 s, 0.5 s, 0.4 s and 0.4 s, respectively) followed in decreasing order by Ultraspeed, Insight, Ektaspeed and the digital systems, the decrease with respect to the first reaching as much as 60%. Regarding the dose administered, Agfa Dentus M2 used the highest dose (3.1 mGy) followed by Ultraspeed (2.7 mGy), Insight (2.2 mGy), Ektaspeed (2.2 mGy) and, finally, the digital systems (1.1 mGy). Statistical analysis showed significant differences between the doses administered for the digital systems with respect to the radiographic films (P < 0.001) and with respect to manual or automatic processing (P < 0.001). However, there were no significant differences in dose between the different types of films themselves, or between the radiographic developing processes themselves (manual and automatic). CONCLUSION: Not even the use of the most sensitive of modern films has brought about a reduction of the dose administered to patients in Spain. Only digital systems, it seems, will bring about reduction in this dose.

Influence of years of professional experience in relation to the diagnostic skill of general dental practitioners (GDPs) in identifying oral cancer and precancerous lesions.

OBJECTIVE: To evaluate skill in diagnosing cancer and oral precancerous lesions among general dentists in the Autonomous Community of Murcia (Spain). MATERIAL AND METHOD: Twenty randomly distributed clinical images were used, of which 45% corresponded to benign lesions, 35% to oral precancerous lesions, and 20% to oral cancer. Each case was accompanied by a summarised clinical history. The study sample comprised 150 general dentists divided into two groups: group I (60 recently graduated dentists without professional experience) and group II (90 dentists with established professional activity). RESULTS: In group I, the sensitivity of oral cancer diagnosis was 61.3% versus 85.5% in group II (p < 0.001), while the sensitivity of precancerous lesion diagnosis was 71.7% in group I versus 80.7% in group II (p = 0.004). CONCLUSIONS: The results obtained show that junior dentists and general dentists with public or private practice need more training and more experience in diagnosing cancer and oral precancerous lesions.

The status of Spain's dental practices following the European Union directive concerning radiological installations.

OBJECTIVES: To assess the influence of new European Union (EU) legislation on dental radiology practices and the reduction in patient radiation exposure. STUDY DESIGN: A total of 7176 official reports from Spanish dental offices or clinics covering the period 1996 to 2001 were analyzed. RESULTS: Of the dental radiological installations inspected in 2001, 72.79% used the kilovoltage recommended by the EU (70 kVp) and 98.85% used at least 1.5 mm Al filtration. At least 90.11% of the installations had a focal film distance of 20 cm although there were no cases with a rectangular collimator as adapted to the size of film. Thirty percent of the installations showed a mechanical fault every year. In 17.62% of cases the radiological film was stored in the exposure room. Few clinics (10.24%) used high-speed films and only 11.95% of clinics employed digital systems. The mean dose received by patients fell during the 5 years studied by 18.75%. Radiological equipment fulfilling the EU specifications emitted significantly lower doses than other nonapproved equipment. CONCLUSIONS: The introduction of legislation has resulted in a gradual improvement in dental radiology practices.