Background and aims: The aim of this study was to measure the microhardness values of irradiated computer-aided design/computer-aided manufacturing (CAD/CAM) ceramics surfaces before and after thermal treatment. Material and Methods: Sixty CAD/CAM ceramic discs were prepared and grouped by material, i.e. lithium disilicate ceramic (Emax CAD) and zirconia ceramic (Emax ZirCAD). Laser irradiation at the material surface was performed with a carbon dioxide laser at 5 Watt (W) or 10 W power in continuous mode (CW mode), or with a neodymium:yttrium aluminum perovskite (Nd:YAP) laser at 10 W on graphite and non-graphite surfaces. Vickers hardness was tested at 0.3 kgF for lithium disilicate and 1 kgF for zirconia.. Results: Emax CAD irradiated with CO2 at 5 W increased microhardness by 6.32 GPa whereas Emax ZirCAD irradiated with Nd:YAP decreased microhardness by 17.46 GPa. Conclusion: CO2 laser effectively increases the microhardness of lithium disilicate ceramics (Emax CAD).
Background and Aims: Chronic foot and ankle joint pain is one of the most frequent complaints which is regularly seen in the out-patient clinic of our medical institute. In previous studies we have reported on the benefits of low level laser therapy (LLLT) for chronic pain in the elbow, hand, finger and the lower back. The present study examined the effects of LLLT on chronic foot and ankle joint pain. Materials and Methods: Over the past 5 years, 17 subjects visited the out-patient clinic with complaints of chronic foot and ankle joint pain of a variety of aetiologies. The patients received LLLT using a 1000 mW semi-conductor laser device, delivering 20.1 J/cm² per point at 830 nm in continuous wave. Each patient was given four shots per session per foot twice a week for 4 weeks. Results: A visual analogue scale (VAS) was used to determine the effects of LLLT for the chronic pain and after the end of the treatment regimen a significant improvement was observed (p<0.01). All but 2 of the patients showed improvement: excellent (2) and good (13). After treatment, no significant differences were observed in the ankle joint range of motion, however. Discussions with the patients revealed that it was important for them to learn how to avoid overuse of the ankle when walking, poor walking posture and a poor pacing technique that would caused them foot and ankle pain in everyday life. Following these postural guidelines could ensure continuous benefits from the treatment. Conclusions: The present study demonstrated that LLLT was an effective form of treatment for chronic foot and ankle joint pain, in conjunction with postural education during all activities of daily living.
Background and aims: After bracket debonding a correct removal of the adhesive from tooth surfaces without causing any iatrogenic damage to the enamel is needed. However, conventional techniques do not allow a selective removal process. The present article focuses on the removal of adhesive on teeth after bracket debonding by using laser radiation at 355 nm (third harmonic wavelength of a Q-switched Nd:YAG). Material and methods: Brackets were bonded to 10 extracted human premolars from young patients and removed after a storage period of 2 months. As real-time diagnostic technique, laserinduced breakdown spectroscopy (LIBS) elemental analysis was applied for precisely controlling the removal of the adhesive and morphological analysis of the etched surfaces was carried out by scanning electron microscopy (SEM). Results: LIBS technique allowed an on-line precise control in the adhesive removal process. SEM analysis revealed the capability of the 355 nm UV laser radiation to complete the removal of the adhesive on the tooth with no signs of damage on the enamel. Conclusions: Laser ablation process at 355 nm monitored by the LIBS technique allows to carry out efficient removal of the adhesive on teeth.
Background and Aims: Laser hair removal has recently become a major indication. Diode lasers have become commercially available offering two modes of application: a stamping or static mode, and a dynamic mode whereby the handpiece is continuously moved across the target tissue. The present study was designed to compare the efficacy of these two approaches clinically and histologically. Subjects and Methods: Twenty-five subjects participated in the study, 12 males and 13 females, ages ranging from 20 to 57 yr (Mean age 41.6 yr). A baseline hair count was performed on both the target areas. The ms-pulsed diode laser delivered 810 nm via a handpiece with a cooled tip, offering both static and dynamic modes which were used on the subjects’ left and right crura, respectively. Pain during treatment was assessed using a visual analog scale (VAS) and gross inspection was performed immediately after treatment for any abnormality in the treated skin. Hair counts were performed on both crura at 1 and 3 months after the treatment, and compared with the baseline counts. Biopsies were performed in the dynamic mode treated skin at baseline and at 1 month after the treatment, and assessed with light microscopy, immunohistochemistry and transmission electron microscopy (TEM). Results: All subjects completed the study. Compared with baseline, hair counts were significantly lower at 1 and 3 months post-treatment with no significant difference between the static and dynamic laser depilation modes, nor in the severity of the pain experienced during the procedure. Histologically, degenerative changes in the hair follicles were noted immediately after laser treatment. At one month, cystic formation was seen in the hair follicles showing a strong tendency towards apoptotic cell death. Conclusions: With the diode laser system and at the parameters used in the present study, high depilation efficacy was seen with no significant difference between the static and dynamic modes. Interestingly, good long-term depilation is probably a result of induced apoptotic cell death in the follicles rather than any other mechanism.
Background and aims: Abdominal circumferential reduction with noncontact high frequency apoptosis-inducing field RF (AiRF) is becoming very popular. The present study compared the treatment results from two different sets of parameters giving the same dose from the same system in an in vivo porcine model. Materials and methods: Two 10 cm x 10 cm areas were symmetrically marked on both sides of the midline (total of 4 areas) over the rectus abdominis muscle of two anesthetized female micropigs. In Animal A (G1), 27.12 MHz AiRF treatment was given at 200 W for 30 min, and 300 W for 20 min in Animal B (G2). Four sessions were performed at weekly intervals. Gross observation by a veterinary specialist was performed on a daily basis. Temperature measurements (fat and skin), clinical photography and ultrasound imaging were carried out at each session. In addition, blood chemistry was performed before each session to check lipid levels, any adverse changes in markers for liver damage in addition to an enzyme-linked immunosorbent assay (ELISA) for raised levels of TNF-α and IL-1β. Biopsies were taken and routinely processed for hematoxylin and eosin, Toluidine blue and oil red O stains to examine for tissue damage at baseline and after each treatment. TUNEL assays were performed to check of apoptotic-related DNA damage. Follow-up assessments included photography, ultrasound, ELISA tests and biopsies which were taken regularly up to 90 days after the final treatment. Results: The maximum adipose tissue temperatures at and over the apoptotic threshold of 43°C were reached and maintained in both G1 and G2. The skin surface temperature was slightly higher in G2 after 20 min than in G1 after 30 min, but was still below 43°C. Gross and magnified observation revealed no appreciable differences or thermally-mediated damage between the skin of either of the two groups after the treatments or during the 90-day follow-up period. No lasting erythema or any other adverse event was seen in either group. The liver enzyme markers showed very similar patterns over the 4 weeks of treatment compared with baseline with no levels outside of the normal range. Triglycerides were all within normal rage with no significant differences between the groups. Remarkably similar patterns were noted for the ELISAs in both groups performed over the 4 weeks of treatment and at periods during the 90-day follow-up with no notable abnormal changes in levels. Staining patterns for both G1 and G2 specimens were similar for all stain types during treatment and the 90-day follow-up, showing decreased numbers of adipocytes by the 90-day point. The ultrasound findings revealed a 44.8% and 55.6% decrease in the adipose layer for G1 and G2, respectively, at the 90-day assessment. Conclusions: The 200 W AiRF treatment for 30 min (G1) and the 300 W AiRF treatment for 20 min (G2) produced very similar results in the porcine model for all assessments and at all assessment points during and up to 90 days after treatment, with slightly better findings suggested for G2. Based on the above findings, the two different settings, delivering the same. dose, produced good results with no skin damage and no adverse events. This has implications in busy clinics for AiRF treatment, where the shorter treatment time could represent time saving for the clinic and the patient without compromising safety and giving equal if not better efficacy.
Background: Peripheral ossifying fibroma associated with neonatal tooth extraction is a rare, benign reactive lesion, but its nature and location often scares the patient & parents for possibility of neoplasm. A high recurrence rate makes its histopathological examination and long term follow up important. Case Report: A 2 months old boy presented with enlarging soft tissue growth on the anterior mandibular ridge. The history revealed extraction of two neonatal teeth at 2 weeks of age. Lesion was excised using 940 nm diode laser and histopathological examination revealed hypercellularity and prominent dystrophic calcification, confirming it to be Peripheral Ossifying Fibroma. There was no recurrence after 18 months follow up. Conclusions: Paediatric dentists should be aware of possible outcomes of natal and neonatal teeth extraction and histopathological features of soft tissue lesions in neonates and infants. This report also highlights that 940 nm diode laser can be safely used for minor oral soft tissue surgeries in neonates and infants.
Background: Although surgical treatment protocols for cleft lip and palate patients have been established, many patients still have some soft tissue defects after complete healing from surgical interventions. These are excess soft tissue, high attached fraena and firmed tethering scares. These soft tissue defects resulted shallowing of vestibule, restricted tooth movement, compromised periodontal health and trended to limit the maxillary growth. The aim of this case report was to present a method of correcting soft tissue defects after conventional surgery in cleft lip and palate patient by using combined laser surgery and orthodontic appliance. Case Report: A bilateral cleft lip and palate patient with a clinical problem of shallow upper anterior vestibule after alveolar bone graft received a vestibular extension by using CO2 laser with ablation and vaporization techniques at 4 W and continuous wave. A customized orthodontic appliance, called a buccal shield, was placed immediately after surgery and retained for 1 month to 3 months until complete soft tissue healing. The procedures were performed 2 episodes. Both interventions used the same CO2 laser procedure. The first treatment resulted in partial re-attachment of soft tissue at surgical area. The second laser operation with the proper design of buccal shield providing passive contact with more extended flange resulting in a favorable outcome from 1 year follow up. Then the corrective orthodontic treatment could be continued effectively. Conclusions: The CO2 laser surgery was a proper treatment for correcting soft tissue defects and the design of buccal shield was a key for success in molding surgical soft tissue.