The aim of this study was to evaluate the morphological effects of diode laser irradiation in the experimentally produced periapical lesion in rat. Fourteen adult male Sprague-Dawley rats weighing approximately 200 gm each were used. Pulp was extirpated from the mesial root of the maxillary first molar using 06 to 25 mm conventional reamers and files. After extirpation, the root canal was exposed to oral flora for 4 weeks to allow periapical periodontitis to develop. After the development of periapical periodontitis, the lesions were irradiated using a diode laser at 5 W for 5 seconds. The root canal was then sealed with cavity filling material for another 4-week period. After 4 weeks, the experimental rats were sacrificed by cervical dislocation. The maxillary first molar was then collected along with the surrounding tissue, which was processed in the laboratory. Hematoxylin and eosin and immunohistochemical staining were used to observe the morphological effects. Proliferating cell nuclear antigen (PCNA), STRO-1 and CD44 were used as the primary antibodies for the immunohistochemical study. A reduction in inflammatory cells, which were mainly composed of lymphocytes, was observed in the periapical lesions after irradiation. The number of PCNA-positive cells increased to approximately twice that observed in the nonirradiated control group. These PCNA-positive cells included STRO-1 and CD44-positive cells, indicating enhancement of wound healing and reduction in inflammatory cells. The present results showed that diode laser irradiation enhanced proliferation of PCNA-positive cells, which included STRO-1 and CD44-positive cells. This increase in these types of cell may improve wound healing in periapical lesions.

Aim: To evaluate and compare the efficacy of Ethylenediaminetetraacetic Acid (EDTA) and Neodymium-Doped Yttrium Aluminum Garnet (Nd:YAG) laser in removing smear layer on root canal dentin after rotary instrumentation. Materials and methods: Sixty extracted maxillary incisor teeth were taken, decoronated and standardized to working length of 14 mm from the apex. All the canals were prepared with NiTi rotary files, rinsed with 1% sodium hypochlorite (NaOCl) and divided into three groups. Group 1 constituted the negative control and was rinsed with saline, group 2 with EDTA and group 3 was exposed to Nd:YAG radiation. The specimens were split longitudinally into two halves and examined under SEM with 1,000× magnification at levels of 2 and 6 mm from apical foramen. Photomicrographs were evaluated by the Hulsmann scoring system and results were tabulated. Scores 1 and 2 were grouped as clean walls and scores 3, 4 and 5 were grouped as smear layer present. Results: Group 1 showed inefficiency in removing smear layer with only 15% clean walls in middle one-third and no clean walls in apical one-third. Group 2 (NaOCl + EDTA) showed 55% clean walls in middle one-third while 15% clean walls in apical onethird while group 3 showed 70% effectiveness in middle onethird and only 15% effectiveness in apical one-third. Conclusion: EDTA and Nd:YAG were found more efficient in smear layer removal than saline. Results of EDTA and Nd:YAG were comparable in apical one-third while Nd:YAG was found to be more efficient than EDTA in middle one-third.

Aim: This study was set out to evaluate the antibacterial efficacy of four disinfection techniques namely needle irrigation, diode laser, Photon-induced Photoacoustic Streaming (PIPS) with Er,Cr:YSGG and EndoActivator in minimally instrumented, experimentally infected root canals. Materials and methods: Eighty single-rooted teeth were selected, prepared to an apical size # 20, taper 0.7; the specimens were sterilized and were inoculated with Enterococcus faecalis for 2 weeks. Disinfection was performed with needle irrigation, 940 nm diode laser, PIPS with 2,740 nm Er,Cr:YSGG laser. After disinfection, aerobic sampling was performed and bacterial counts (colony-forming units) and the incidence of positive samples after 24 hours and 7 days were determined. Results: After the two time periods, all four disinfection protocols reduced the bacterial load when compared to the pretreatment load. None of the techniques predictably generated negative samples, but diode laser and PIPS with Er,Cr:YSGG was superior, when compared to needle irrigation and EndoActivator in this aspect. No statistically significant difference was found between needle irrigation and EndoActivator. Conclusion: Diode laser disinfection demonstrated significant elimination of E. faecalis in minimally instrumented canals. PIPS with Er,Cr:YSGG and EndoActivator reduced the bacterial load when compared with needle irrigation.

This ex vivo study investigates the effectiveness of the new design of the tip of Er,Cr:YSGG laser (BIOLASE_TM) in removing the smear layer at the apical third of curved root canals. Eighty one freshly extracted intact single rooted human mandibular premolar teeth with 15° to 30° canal curvature were selected and decoronated at the level of the cementoenamel junction. The roots were divided into three main groups with 27 samples each. Group I—non-lased teeth, group II—teeth lased with plain tip and group III—teeth lased with conical tip. Each group was further divided into three subgroups of nine samples each with 2 ml of 17% (Ethylene diamine tetraacetic acid (EDTA), 2 ml of 2% chlorhexidine (CHX), 2 ml of 3% sodium hypochlorite (NaOCl) respectively. In all the three groups, canals were prepared with rotary nickel-titanium (NiTi) instruments to a working length 1 mm short of the apex to size F3, using ProTaper instruments. The fiber tips were placed into the appropriate irrigant solution in the root canal to a depth of 1 mm short of working length and then activated for 20 seconds. The teeth were split longitudinally and subjected to scanning electron microscopy (SEM) at 1000×. It can be concluded that to ensure complete removal of smear layer from the root canal system it may be prudent to activate EDTA with conical tip design of Er,Cr:YSGG laser during irrigation protocol in the curved root canals.

This paper is based on previous research carried out on the topic of oral hygiene. In this literature review, various studies have been considered, some from outside of India as well as some from within India, which is the origin of our research. This was done to obtain a global view of the topic and also to be able to compare how Indian oral hygiene and awareness compares with the same for the rest of the world. In a study conducted in 2011 that pertained to the oral health practices was conducted in the rural areas of the Kanchipuram District in Tamil Nadu, India. The participants were children between the ages of 5 and 10. The mean age of the children was 8.5 years and there were a total of 81 participants. The aim of this survey was ‘to evaluate the awareness and knowledge among the rural children on the dental health problems, their oral hygiene practices and the pattern of practices of dental treatment.’ A number of results pertained to the oral health practices of the participants. A number of results pertained to the oral health practices of the participants were found in the study by authors VC Punita, P Sivaprakasam, in the rural children of Kanchipuram in the year 2011.¹⁴ Out of the 81 children participating, only 51 children used toothbrushes while the rest used their fingers as a tool to clean their teeth. That accounts to only 62.96% brushing their teeth with brushes. This is attributed to the children coming from a ‘very low socioeconomic background’. It was reported that 92.59% of the participants brushed their teeth once a day and 7.40% brushed twice a day. Moreover, only 45 out of the 81 children used toothpaste (55.55%) while the rest used twigs of the Azadirachta indica plant, traditionally known as datum, in combination with chalk powder, charcoal or sand. From the children who used brushes, 50.98% of them changed their brush when it got worn out, 27.44% of the participants changed their brush every 3 to 6 months. While the rest did not know how often they changed their brush. The author concludes that ‘by giving adequate information, motivation and practice of the measure to the subject’ this situation can be improved. In recent study done in 2012 authors Mehta A and Kaur G, it was found that 71.4% of the participants used a toothbrush with toothpaste, which is significantly higher than the 62.69% used by participants in the previously described study.18 Moreover, in this study, only 1.4% of participants used the Azadirachta indica twigs to clean their teeth, which is a significantly better result than the previous study. In this study, 25% of participants brushed their teeth more than once a day, which is a major improvement over the 7.40%, reported in the previous experiment. In a study conducted by Amin and Al-Asad on the ‘Oral hygiene practices, dental knowledge, dietary habits and their relation to caries among male primary school children in Al-Hassa, Saudi Arabia’ (2008). This study showed similar results in Saudi Arabia to those in the first study discussed. A total of 24.5% of the students brushed their teeth more than twice a day. However, 44.6% of the students used Malwak which is similar to the Azadirachta indica used in the first and second studies. Another important study was conducted in Bangalore, which focused on various oral practices and oral health in missionary schools in Bangalore. They studied the oral health of school children of the age 11- to 12-year-old.19 From all the participants studied, 5.4% of them smoked cigarettes at least once a week while 3.9% of the chewed tobacco at least once a week. These results are eye opening as the children who took part in the experiment were 11 to 12 years old and tobacco use at such a young age is extremely harmful. Another important segment of our study is tobacco use. Tobacco is classified in two forms, one which is smoked and the other which is used in forms other than being smoked. Smoked tobacco includes cigars, cigarettes, pipes, hookahs, bidis and kreteks. Smokeless forms of tobacco include betel nut, pan, pan masala and snus. The other articles lacked knowledge about tobacco use in the participants. Another aspect of our study is the diet of our participants. A study was conducted to compare oral habits and oral health knowledge in American school students living in Amritsar and Indian school children living in the same city.²⁰ It was concluded that the diets of the school students compared was found to be ‘comparable.’ (Grewal and Kaur (2007). This was attributed to the urbanization of cities in India. However, the hygiene practices in the group of Indian participants was different from that of the American participants. The author suggests the hygiene practices in the group of Indian participants have not changed over time. The last aspect of our study is oral health knowledge. In the study conducted in the Panchkula district, it was found that 83.2% of participants knew the importance of brushing regularly.¹⁸ Moreover, 69.5% of participants stated that the importance of visiting a dentist regularly, which is to maintain healthy teeth. Around 17.6% of the participants knew the benefit of using toothpaste which contained fluoride. Lastly, 41.8% of the participants knew that the consumption of sugary foods can result in dental caries.

Excessive gingival pigmentation is a major esthetic concern for many people. Melanin pigmentation is known to be caused by melanin granules within the gingival epithelium. Though it is not a medical pathology, many people complain of dark gums as unesthetic. A case is reported here of hyperpigmentation treated with scalpel, diode laser and electrosurgical procedure in a split mouth design with a note on comparison of healing.

Different external whitening procedures utilizing highly concentrated hydrogen peroxide formulations can be used for tooth bleaching and tooth whitening. Light can be used to enhance or accelerate the bleaching process. Laser bleaching gels incorporate laser absorption-enhancing particles which are used to accelerate the whitening process. This case report describes the procedure for the use of Biolase LaserWhite20™ whitening gel and Ezlase 940 nm laser in a patient requesting teeth whitening.