The purpose of the present study was to analyse clinically failed and retrieved implants prior to and after cleaning by means of scanning electron microscopy (SEM) and X-ray induced photoelectron spectroscopy (XPS) as compared to unused controls. Six different chemical and physical techniques for cleaning of contaminated titanium implants were evaluated: 1) rinsing in absolute ethanol for 10 min, 2) cleaning in ultrasonic baths containing trichloroethylene (TRI) and absolute ethanol, 10 min in each solution, 3) abrasive cleaning for 30 s, 4) cleaning in supersaturated citric acid for 30 s, 5) cleaning with continuous CO2-laser in dry conditions at 5 W for 10 s, 6) cleaning with continuous CO2-laser in wet conditions (saline) at 5 W for 10 s. SEM of failed implants showed the presence of contaminants of varying sizes and XPS showed almost no titanium but high carbon signals. XPS of unused titanium implants showed lower levels of titanium as previously reported, probably due to contamination of carbon which increased with time in room air. Cleaning of used implants in citric acid followed by rinsing with deionized water for 5 min followed by cleaning in ultrasonic baths with TRI and absolute ethanol gave the best results with regard to macroscopical appearance and surface composition. However, as compared to the unused implants the results from an element composition point of view were still unsatisfactory. It is concluded that further development and testing of techniques for cleaning of organically contaminated titanium is needed.

Objective: The aim of this study was to evaluate the effect on dentinal surfaces of diode lasers (810 and 980 nm) at different parameters. Materials and methods: Twenty-four caries-free human impacted wisdom teeth were used. The crowns were sectioned transversely in order to expose the dentin. The smear layer was removed by a 1 min application of ethylenediaminetetraacetic acid (EDTA). Each surface was divided into four quadrants irradiated at a different output power setting for each kind of laser: 0.8, 1, 1.6, and 2 W (energy densities: 2547, 3184, 5092, and 6366 J/cm 2 , irradiation speed 1 mm/sec; optical fiber diameter: 200 lm; continuous and noncontact mode). Half of the samples were stained with a graphite paste. All specimens were sent for scanning electron microscopic (SEM) analysis. Pulp temperature increases in additional 20 teeth were measured by a thermocouple. Results: Diode laser irradiations at 0.8 and 1 W led to occlusion or narrowing of dentin tubules without provoking fissures or cracks. The application of graphite paste increased the thermal effects in dentin. Measurements of pulp temperature showed that irradiations at 0.8 and 1 W for a period of 10 sec in continuous mode increased pulp temperature (T £ 2°C). Conclusions: Diode lasers (810 and 980 nm) used at 0.8 and 1 W for 10 sec in continuous mode were able to seal the dentin tubules. These parameters can be considered harmless for pulp vitality, and may be effective in the treatment of dentinal hypersensitivity.

While the results reported in this study are not conclusive, they indicate that laser therapy has potential to improve management of BON.

Objective: Trauma during dental surgery is a predisposing factor for bisphosphonates (BP)-related osteonecrosis of the jaws (BRONJ). However, about 40% of cases of BRONJ are not related to dental invasive procedures, being probably associated to endodontic or periodontal infections. Extraction of non-treatable teeth is considered a reliable choice, to improve symptoms and to reduce the risk of BRONJ. Here we report our experience of tooth extractions in patients under oral or intravenous BP therapy. Study Design: Two-hundred and seventeen patients (38 males, 179 females; mean age 68.72 ± 11.26 years, range 30 to 83 years) under BP therapy received 589 tooth extractions at the Unit of Oral Medicine, Pathology and Laser-assisted Surgery of the University of Parma, Italy, between June 2006 and December 2010. Ninety five patients were under BP therapy for oncological disease (multiple myeloma (MM): 23; bone metastases (BM): 72) and 122 patients for non oncological diseases: 119 osteoporosis (OP), 2 rheumatoid arthritis (RA) and 1 Paget’s disease (PD). The mean duration of BP was of 35 months. Antibiotic treatment was administered three days before and 2 weeks after tooth extractions. Patients were additionally treated with low level laser therapy (LLLT) through Nd:YAG laser (1064 nm – power 1.25 W; frequency 15 Hz; fibre diameter: 320 ?m), 5 application of 1 minute each. Patients were evaluated 3 days and once a week for 2 months after the extractions and every time they received LLLT. Mean follow-up was 15 months (ranging from 4 to 31 months). Results: In a total of 589 extractions (285 mandibular, 304 maxillary) performed, a minimal bone exposure was observed in 5 cases, treated with Er:YAG laser vaporization and than healed. Conclusions: Our experience supports the hypothesis that the association of antibiotic treatment and LLLT can be effective in preventing ONJ after tooth extractions in patients under BPT. Key words:Nd:YAG laser, low level laser therapy, tooth extractions, bisphosphonates, jaws osteonecrosis.

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