Clearfil Protect Bond™ versus Uni-Etch™ antibacterial self-etchant: A war of giants against shear bond strength.

AIMS AND OBJECTIVES: To use antibacterial agents with two conventional bonding systems and evaluate the shear bond strength (SBS) of bracket to enamel. MATERIALS AND METHODS: Overall, 120 human-extracted first premolars were used. The specimens were equally divided into six sub-groups of 20 samples. Control groups were bonded with Transbond XT™ light cure (Group I, after etching with 37% phosphoric acid, 3M Unitek™ ) and Unite™ self-cure adhesive (Group II, after etching with 37% phosphoric acid, 3M Unitek™ ). Experimental groups included teeth surface first coated with Clearfil Protect Bond™ (Kuraray, Osaka, Japan) (and then bonded with Transbond XT™ [Group III] or Unite™ [Group IV]) or bonded with Uni-Etch™ antibacterial self-etchant (and then bonded with Transbond XT™ [Group V] or Unite™ [Group VI]). The third generation MBT bracket bonding system with 0.022 slots was used for bonding. All specimens were tested on Instron machine 5567 (SIES Institute of packaging, Nerul, Navi Mumbai, India) to evaluate the SBS. The sheared surfaces were also investigated with a stereomicroscope to assess adhesive remnants index (ARI scores) on the specimen surfaces. RESULTS: Mean SBS in Group I-Group VI was 10.53 (2.91), 9.12 (2.56), 9.86 (1.98), 6.96 (2.92), 9.57 (2.02), and 7.65 (2.34) megapascals, respectively. Significant differences were only seen between Group III and IV and between Group II and IV. With respect to ARI scores, significant differences were seen only for comparison between Groups II, IV, and VI. CONCLUSION: Newly developed antibacterial agent could be used with conventional bonding systems effectively to decrease white spots; when used with Transbond XT™ light cure, the original SBS did not get affected, but when used with Unite™ self-cure bonding system, it led to reduced SBS significantly.

Review of drug treatment of oral submucous fibrosis.

This study undertook a review of the literature on drug treatment of oral submucous fibrosis. An electronic search was carried out for articles published between January 1960 to November 2011. Studies with high level of evidence were included. The levels of evidence of the articles were classified after the guidelines of the Oxford Centre for Evidence-Based Medicine. The main outcome measures used were improvement in oral ulceration, burning sensation, blanching and trismus. Only 13 publications showed a high level of evidence (3 randomized controlled trials and 10 clinical trials/controlled clinical trials), with a total of 1157 patients. Drugs like steroids, hyaluronidase, human placenta extracts, chymotrypsin and collagenase, pentoxifylline, nylidrin hydrochloride, iron and multivitamin supplements including lycopene, have been used. Only systemic agents were associated with few adverse effects like gastritis, gastric irritation and peripheral flushing with pentoxifylline, and flushingly warm skin with nylidrin hydrochloride; all other side-effects were mild and mainly local. Few studies with high levels of evidence were found. The drug treatment that is currently available for oral submucous fibrosis is clearly inadequate. There is a need for high-quality randomized controlled trials with carefully selected and standardized outcome measures.

Involvement of viral factors with head and neck cancers.

The incidence of head and neck cancer remains high and is associated with many deaths in both Western and Asian countries. Common risk factors in head and neck carcinoma are smoking and alcohol abuse, however, in an increasing proportion of cases, no significant smoking or drinking history has been reported. The infectious nature of oncogenic viruses sets them apart from other carcinogenic agents. As such, a thorough study of both the pathogenesis of viral infection and the host response is crucial to a full understanding of the resulting cancers. Such an understanding, in turn, has increased our knowledge of cellular pathways involved in growth and differentiation and neoplasia as a whole. Even though human oncogenic viruses belong to different virus families and utilize diverse strategies to contribute to cancer development, they share many common features. Viruses linked to cancers in humans are the human papilloma viruses, Epstein-Barr virus, hepatitis C virus and human herpesvirus-8. The potential role and involvement of these viruses in head and neck cancers along with brief description of vaccine development is provided.