Investigating the antibacterial effect of chitosan in dental resin composites: a pilot study

The tendency of [resin-based composites] RBCs to allow more plaque formation results in secondary caries. Chitosan [CS] inhibits the growth of Streptococcus mutans [S.mutans]; which is most frequently caries causing bacteria. Therefore, CS was incorporated into RBCs to determine its in vitro antibacterial activity against S.mutans. CS was added to flowable and microhybrid RBCs at various concentrations of 0 [control] 0.25, 0.5 and 1.0% by weight. Five disc shaped specimens [15mm diameter, 2mm thickness] were prepared for each experimental and control group. Interaction of cured chitosan modified RBCs with S. mutans biofilms was evaluated using agar diffusion test method. The results of ADT were negative. The experimental RBCs containing CS did not show growth inhibition zone around lawn growth of S.mutans compared to control group. Further experiments are in progress to determine CS modified RBCs antibacterial efficacy by direct contact test. Within the limitations of this study Antibacterial activity of CS modified RBCs is comparable to that of commercial RBCs when evaluated by agar diffusion test method

Frequency of second canal in maxillary second premolars [ex-vivo study]

The objective was to determine the frequency of second canal in extracted maxillary second premolars. This was an in vitro study conducted at the Department of Operative Dentistry, Liaquat University of Medical and Health Sciences, Jamshoro from October 2011 to March 2012. This study included two hundred extracted human maxillary second premolars. The pulp chambers were accessed with round bur in a high speed air turbine, and they were irrigated with 2.5% sodium hypochlorite solution for 12 hours to dissolve the pulp tissues, then rinsed under running tap water for 2 hours and dried overnight. The dye was introduced coronally and flooded throughout the pulp space by vacuum suction apically. Teeth were then decalcified in 5% nitric acid solution for five days. Eventually teeth were made clear by dipping in methyl salicylate and examined under operating microscope under 7.5 x magnification for the frequency of second canal. Results showed that the frequency of second canal of the maxillary second premolars is 37% [74/200]. Chi-square test was used to evaluate the results. It was concluded that dentists must always look for the second canal during endodontic treatment of the maxillary second premolars

Frequency of second canal in mandibular lateral incisors [in-vitro]

Objective of the study was to determine the frequency of second canal in extracted mandibular lateral incisors. It was observational study and was conducted in the Dental Outpatient's Department of Liaquat University of Medical and Health Sciences Hospital, Hyderabad / Jamshoro from 1st January 2010 to 31th March 2010. This study included 100 extracted permanent mandibular lateral incisors. These extracted teeth were stored in 10% formalin until access preparation was made. Pulp chamber was accessed using round bur and then irrigated with sodium hypochlorite till it is clearly visible. Then DG16 endodontic explorer was used for the location and negotiation of second canal after location of main canal. Teeth in which second canal was located, No. 10 K-files were inserted into main canal and second canal. Then two periapical radiographs from the buccolingual and proximal sides were taken for confirmation. Results were then recorded in proforma. Single canal was found in 61% of permanent mandibular lateral incisors. 39% of permanent mandibular lateral incisors had second canal. The frequency of second canal in the present study was 39% of permanent mandibular lateral incisors

Dental resin-based composites: a transition from macrofilled to nanofilled

The invention of dental resin based-composites [RBCs] has provided a broad range of materials for the restoration of load-bearing posterior teeth with excellent clinical results and adequate longevity. A variety of RBCs, namely "microhybrid", "nanohybrid" and "nanofilled" have been marketed with bold claims of a technological advancement. Although "microhybrid", "nanohybrid" and "nanofilled" RBCs have exhibited a degree of clinical and experimental success compared with their predecessors, however, it is difficult to justify which RBC is superior as a result of slight variations in filler size and associated interchangeable mechanical and physical properties of RBCs. The objective of the current review article is to highlight the development of various filler particles of dental RBCs and resultant variation in mechanical and physical properties which may ultimately provide directions for future research on the RBCs

Selecting the appropriate electrode placement-site for electrical pulp testing of molar teeth

The objective of the present experimental study was to report an appropriate electrode placement site on first molar teeth. Fifty volunteers with sound mandibular and maxillary first molar teeth [without any lesion or restoration] were selected from the Dental OPD of Dept of Operative Dentistry LUMHS Jamshoro from July 2008 to June 2009. Seven sites on each tooth were tested two times. The Elements Diagnostic Unit EPT was used to record the lowest threshold response of each site. Data was analyzed with one-way analysis of variance and the tukey test. The central fossa/pit of both maxillary and mandibular first molar teeth was found to be an appropriate site for EPT testing. Whereas, the tip of mesiobuccal cusp was the second site where lowest thresh hold was found to elicit pulpal response. No significant difference was observed between male and female subjects and between mandibular and maxillary molars. The experiment showed that the central pit might be an optimum site for placement of EPT probe tip

Frequency of interappointment pain observed with sodium hypochlorite and hydrogen perioxide based root canal irrigants

To compare the frequency of interappointment pain between 2.5% Sodium Hypochlorite and 3% Hydrogen Peroxide as a root canal irrigationmaterial. Clinical trial. Study was conducted at Dental OPD, Liaquat University of Medical and Health Sciences, Jamshoro, Pakistan from February 2009 to July 2009. Sixty single-rooted, single-canal permanent teeth of sixty patients were selected randomly and equally divided in two groups. In group A[n=30], 2.5%Sodiumhypochlorite [NaOCl]was used as an irrigation material while in group B [n=30], 3% Hydrogen peroxide [H2O2] was used. Canals were left empty for 72 hrs between visits. On second visit, interappointment pain was scored on Visual Analogue Scale [VAS] [0= No pain,1- 3=mild, 4-6=moderate, 7-10= severe] by each patient on the proforma provided.: Interappointment pain was observed in 32/60 patients and the rest did not experience any pain. Pain was significantly high in group B than A[70% vs. 36.7%; p=0.01]. Severity of pain was also compared which was significantly high in group B than group A [p<0.012]. Female experience more pain as compared to male. While correlation of age with pain was not found [p>0.05]. NaOCl performed better clinically in terms of interappointment pain when comparedwithH2O2