Dry Eye — A Clinical Study in a Hospital Based Population.

Objectives: To determine the prevalence of dry eye based on dry eye symptoms attending the Department of Ophthalmology and Medicine, Tripura Medical College. Materials and Methods: This study was conducted at Tripura Medical College, Hapania, Agartala, from 1st December 2009 to 31st December 2010. Complete history and ocular examinations was recorded on a pre designed proforma in the Department of Ophthalmology. The diagnosis was made from history and objective dry eye test in the following sequence: tear meniscus height, tear break up time test,fluorescein staining, schirmer test, and rose Bengal staining. If 2 or more of the above test were positive, the patient was deemed to be suffering from dry eye. All patients were sent to the Dept. of Medicine for systemic examination and to rule out any systemic diseases. Results: In this study, total number of patients that presented with dry eye symptoms were 762 and among them dry eye was diagnosed in 403 patients. The Prevalence rate was 3.10% and it was highest in the age of more than 70 years of age. Females had higher prevalence (1.94%) than males (1.15%). Conclusion: The prevalence of dry eye is less in Tripura at around 3.10%. This may be due to the geographical and climatic implication with a high degree of humidity reigning in this region.

Heat fixed but unstained slide smears are infectious to laboratory staff.

Background and Aim: In a clinical microbiology laboratory, heat fixed slide smears are commonly transported from one place to another for staining with different stains and also for onsite proficiency testing of laboratory technicians for accreditation of the laboratories. These smears are frequently handled without gloves by the staff in developing countries. Therefore, this study was conducted to check the survivability of tubercle bacilli on smears after physical and chemical treatments. Methods: A total of 196 AFB positive smears were analyzed. Of these, 116 were stained with Ziehl Neelsen (ZN), 60 with cold Kinyoun and 10 were unstained but heat fixed and 10 were neither stained nor heat fixed. The last 20 smears served as controls. The ZN and Kinyoun stained smears were 0-1.5-year-old and stored at room temperature in slide boxes, while control smears were freshly prepared. All smears were prepared from sputum samples positive for acid fast bacilli. All four sets were subjected to slide culture to see if mycobacteria could survive and grow in any. For slide culture, a new and safe device was used, which is designed for three in one purpose: cell cultivation, direct observation of the growth under microscope and cell harvesting inside the closed tube. The slide smears were directly dipped into this tube that contained liquid culture medium. The tubes were incubated at 370C for four weeks. The growth, if any, was confirmed by MPT-64 rapid test and subculture on LJ slants. Results: No growth was observed in ZN and Kinyoun stained slide smears. However, significant growth was observed in both control sets; the unstained non heat fixed as well as heat fixed slide smears. Conclusions: The results of our study indicate that tubercle bacilli remain viable even after heat fixation and carry risk of infection by contact. However, stained smears are safe for handling and storage.

Hip-implant related chorio-retinal cobalt toxicity.

A 39-year-old female with elevated serum cobalt levels from her bilateral hip prostheses presented with a 3-week history of blurred vision in her left eye. Optical coherence tomography revealed patchy degeneration of the photoreceptor-retinal pigment epithelium (RPE) complex. The lesions were hypofluorescent on indocyanine green angiography. We postulate that this is a case of implant-related chorio-retinal cobalt toxicity.

Role of delayed light polymerization of a dual-cured composite base on marginal adaptation of class II posterior composite open-sandwich restoration.

Objective: To determine the effect of delayed light polymerization of a dual-cured composite base material on the marginal adaptation of class II composite restoration. Materials and Methods: 35 extracted human molar teeth were used to prepare class II mesio-occlusal or disto-occlusal slot preparations with gingival margins at the CEJ. The teeth were restored using an open-sandwich technique with a 2mm base increment of dual-cured composite, and divided into 5 groups based on the mode of the polymerization of the dual-cured composite base: Group A - self-cured after placement (5 mins), Group B - light-cured immediately after placement, Group C - light-cured 30 seconds after placement, Group D - light-cured 60 seconds after placement, Group E - light-cured 120 seconds after placement. Then a top layer of a light-cured composite resin is placed to complete the restoration. The teeth were thermocycled and immersed in 1% aqueous solution of methylene blue for 24 hours. Sectioning of the teeth and scoring under stereomicroscope was done. Data will be statistically evaluated using the kruskal wallis 1-way ANOVA. Results: Statistical analysis using kruskal wallis 1-way ANOVA showed that the dual-cured composite light polymerized 1 minute after placement exhibited the least microleakage. Conclusion: Delayed light polymerization of the dual-cured composite base reduced the microleakage in class II open-sandwich restorations.

In vitro study of microleakage of different techniques of surface preparation used in pits and fissures.

Objective : The purpose of this in vitro study was to evaluate the effect of different techniques of surface preparation on the microleakage of a sealant applied with traditional acid etching and self-etched bonding agent. Study Design : A total of 60 extracted third molars were randomly assigned into six groups (n = 10/each). The occlusal surfaces were sealed with a sealant (Clinpro) after one of the following pretreatments: (1) phosphoric acid etching; (2) Prompt L-Pop; (3) laser + etching; (4) laser + Prompt L-Pop; (5) air abrasion + etching; (6) air abrasion + Prompt L-Pop. The specimens were immersed in a 0.5% basic fuchsin solution. Buccolingual cuts parallel to the long axis of the tooth were made. The surfaces were scored 0--2 for extent of microleakage using a microscope and the data were analyzed statistically. Results : The poorest results were obtained with laser + Prompt L-Pop which showed a greater number of specimens with microleakage (80%). Air abrasion surface preparation + phosphoric acid etching showed less microleakage than the other groups (40%). Kruskal--Wallis and t-tests revealed no significant difference in microleakage between six groups. Conclusion : The self-etching adhesive studied seems an attractive alternative to the acid-etch technique for sealant application in young children where simplifications in the clinical procedure are warranted. No significant difference was noted between the different types of enamel preparation before fissure sealant.

Comparative evaluation of expression of proliferating cell nuclear antigen in variants of ameloblastoma and ameloblastic carcinoma.

Aim: To evaluate the use of proliferating cell nuclear antigen index in the different histopathological variants of ameloblastoma, such as the follicular, plexiform, and unicystic types, and in ameloblastic carcinoma by immunohistochemical staining. The proliferating cell nuclear antigen index values of the variants of ameloblastomas and ameloblastic carcinomas are compared in order to determine the biological behavior of these tumors. Materials and Methods: For the present study, archival tissues that had been diagnosed as ameloblastoma and ameloblastic carcinoma were collected from the department of oral pathology. Specimens were embedded in paraffin wax and were sectioned at a thickness of 5 μm and stained with hematoxylin-eosin for reconfirming the histologic pattern. It was also stained immunohistochemically for anti-proliferating cell nuclear antigen antibody. Results: Positive proliferating cell nuclear antigen expression is seen as a light brown, granular stain. The proliferating cell nuclear antigen values of ameloblastic carcinoma were almost five times the value of ameloblastoma. Analysis of variance test, Fischer's exact test/variance ratio test, and Student's t-test were performed and the probability values were determined. Summary and Conclusion: This study showed that ameloblastic carcinoma had the maximum proliferative capacity. Among the variants of ameloblastoma, the plexiform variety had the maximum proliferative capacity, followed by the follicular and unicystic varieties. Altogether, these data indicate that proliferating cell nuclear antigen is related to the biological behavior and proliferation of tumor cells in the variants of ameloblastoma and ameloblastic carcinoma.

Colposcopy: A new ray in the diagnosis of oral lesions.

Oral squamous cell carcinoma is the most common cancer of the oral cavity. The survival rates for oral cancer patients will significantly be improved provided lesions are detected and treated at the infancy stage. Early diagnosis is therefore of paramount importance. Histopathological examination is considered as the gold standard in diagnosing oral lesions. Therefore, the selection for a biopsy site is highly significant. In this article, we present a current review of the colposcope and oral application of the colposcopy technique and its use as an adjunct in the early diagnosis of premalignant and malignant lesions of the oral mucosa. We stress upon the fact that colposcopy (direct oral microscopy) of oral mucosal lesions helps in selecting more representative sites for biopsy than routine clinical examination alone. Because of its precision, versatility, ease of use, and being a non-invasive technique, colposcopy might prove to be a useful step toward continuing to learn and improve the care for our patients.

Comparison of apical sealing and periapical extrusion of the ThermaFil obturation technique with and without MTA as an apical barrier: An in vitro study.

Aim: The aim of the study was to compare the conventional ThermaFil obturation technique and ThermaFil obturation with mineral trioxide aggregate (MTA) as an apical barrier, with regard to apical sealing and extrusion. Materials and Methods: Twenty extracted human canines were instrumented using a crown-down technique and divided into two groups. The experimental group was obturated using ThermaFil obturation with MTA as an apical barrier and the control group was obturated using the conventional ThermaFil obturation technique. AH Plus sealer was used in both the groups. Apical extrusion was recorded. Teeth of both the groups were coated with nail polish, except for the apical 3 mm. After 24 h, they were suspended in black India ink for 48 h. Canines were decalcified, rendered transparent, and linear dye penetration was measured under ×40 stereomicroscope. Results: There was a significant extrusion noticed in conventional ThermaFil obturation technique. Frequency of extrusion of sealer and/or gutta-percha was supposed to be evaluated using χ² test, but since the values of the samples of ThermaFil plus MTA group were zero, statistical analysis could not be conducted, whereas linear dye leakage was calculated with Mann-Whitney U test because the distribution was abnormal. Conclusion: Although ThermaFil plus MTA group showed microleakage, extrusion of sealer and the core material was prevented in comparison with conventional ThermaFil obturation technique. It is advantageous to use MTA as an apical plug as there is no fear of apical extrusion and the root canal system can then be packed three dimensionally against this barrier using any thermoplasticized gutta-percha obturation technique.

The effectiveness of magnesium oxide combined with tissue conditioners in inhibiting the growth of Candida albicans: An in vitro study.

Context : The presence of Candida albicans on the fitting surface of the denture is a major causative factor in denture stomatits. A treatment method is by combining tissue conditioner and antifungal agents. Aims : The main objective of this study is to test the efficacy of magnesium oxide combined with two tissue conditioners (Viscogel and GC Soft), in inhibiting the growth of Candida albicans. Settings and Design : Microbiological study was done in the Department of Microbiology, K S Hegde Medical Academy, Nitte University, Mangalore. Materials and Methods : A total of 154 plates were prepared using Muller Hilton with Glucose and Methylene Blue dye medium and inoculated with 24-hr old standard Candida culture. Plates were divided into control and combination. Test discs with different concentrations of MgO were equidistantly placed in MgO Control, while sterile discs embedded with respective tissue conditioner were equidistantly placed in Viscogel and GC Soft controls. For combination groups, the tissue conditioners were mixed and the discs with MgO (1%, 3%, 5%, and 7%) were embedded in the mix. After 24 h of incubation, inhibition diameters were noted. Statistical Analysis Used : The data was analysed using Mann Whitney U Test, ANOVA, Tukey HSD test. Results : The inhibition effect of magnesium oxide 1% combined with tissue conditioners (VGC and GCC) is not significant in both the groups. The inhibition effect of MgO 5% and 7% combined with tissue conditioners (VGC and GCC) is very highly significant ( P < 0.001). Conclusions : Magnesium oxide in combination with tissue conditioners are effective against Candida albicans; GC soft with magnesium oxide showed a better result than Viscogel with magnesium oxide; Increasing the concentration of magnesium oxide increases the zone of inhibition of Candida albicans.

In vitro evaluation of cytotoxicity of denture adhesives.

Aim: The aim of the study is to assess and compare the cytotoxicity of commercially available four denture adhesives ex-vivo. Materials and Methods: Four commercially available denture adhesives namely Metrodent powder, Fixon powder, Dentiro powder and Fixon cream were selected. Normal saline was used in control group. To evaluate the cytotoxicity of denture adhesives, macrophages were isolated from peritoneal cavity of Swiss albino mice and cell integrity/cell viability method was done by using trypan blue dye. Results: Viable cells were counted and subjected to statistical analysis. ANOVA, F and 't' test were performed, which showed statistically significant values (P < 0.001). The mean percentage of viable cells was highest in the control group (95%) and lowest in Fixon powder (55.66%), with Dentiro powder the mean percentage of viable cells was 63.66%, with Metrodent powder 67.6% while with Fixon cream it was 69.33%. Conclusion: All tested denture adhesives showed varied degree of cytotoxicity that is statistically significant. The degree of toxicity was more in Fixon powder followed by Dentiro powder and Metrodent powder with least in Fixon cream.

Stromal differences in odontogenic cysts of a common histopathogenesis but with different biological behavior: A study with picrosirius red and polarizing microscopy.

Objectives: The present study was undertaken to detect and compare the pattern of collagen fibers in odontogenic cysts and also to find out if this methodology could be used to predict the aggressive nature of odontogenic cysts by comparing with the odontogenic tumors. Materials and Methods: The collagen in the wall of 11 odontogenic keratocysts, 14 dentigerous cysts and 14 radicular cysts was studied histochemically by staining sections with picrosirius red and examining under polarizing microscope. This was compared to 10 cases of odontogenic tumors using Z test of proportion at 1% and 5%. Results: In dentigerous cysts, odontogenic keratocysts and odontogenic tumors, the predominant color of collagen fibers birefringence was found to be orangish red, whereas in radicular cysts the collagen fiber was of green color. Conclusions: Similar birefringence pattern of collagen fibers between dentigerous cysts, odontogenic keratocysts and odontogenic tumors may indicate that these lesions have a common histogenesis with a broad spectrum of biological behavior and belong to the same group, i.e., are developmental in origin. Different patterns of radicular cysts suggest different biological behavior and a positive role of inflammation on polarization color of collagen fibers.

Rotary Mtwo system versus manual K-file instruments: Efficacy in preparing primary and permanent molar root canals.

Aim: To compare the cleaning ability and preparation time of rotary instruments (Mtwo) and conventional manual instruments (K-file) in preparing primary and permanent molar root canals. Materials and Methods: Access cavities were prepared in 70 primary and 70 permanent teeth and India ink was injected into 120 canals of selected molars. The teeth were randomly divided into two main subgroups (n=20) and three control groups (n=10). In each of these main subgroups, either the manual instrument (K-file) or the rotary system (Mtwo) was used to prepare root canals. After cleaning the canals and clearing the teeth, dye removal was evaluated with the help of a stereomicroscope. In addition, the time needed for root canal preparation was recorded by a chronometer. Statistical Analysis: Statistical analyses were done using the Kruskal-Wallis, Mann-Whitney and t tests. Results: With regard to the cleaning ability of root canals, there were no significant differences between the K-file and Mtwo rotary system in primary and permanent teeth in the apical, middle or coronal third of the canals. Moreover, there were no significant differences between primary and permanent teeth prepared with K-files and rotary instruments. In all the groups, shorter times were recorded with the rotary technique. The working time was shorter in primary than in permanent teeth. Conclusion: The Mtwo rotary system showed acceptable cleaning ability in both primary and permanent teeth, and achieved results similar to those of K-files in less time.

Immunohistochemical detection of human telomerase reverse transcriptase in oral cancer and pre-cancer.

Purpose: Telomerase is a specialized ribonucleoprotein complex that stabilizes telomeres by adding "TAG" repeats to the end of chromosomes. The catalytic subunit of telomerase is human telomerase reverse transcriptase (hTERT), whose expression is the critical determinant of telomerase activity. Telomeres and telomerases play an important role in the longevity of cell and are known to conform "immortalization" on neoplastic cells. Although there exists a lot of information on telomerase in oral cancer, very little is known about their expression in leukoplakia and oral submucous fibrosis (OSF). This study addresses this lacuna. Materials and Methods: In this preliminary study, immunohistochemistry (IHC) was used to detect the expression of hTERT protein in oral squamous cell carcinoma (OSCC) (n=30), leukoplakia (n=15), OSF (n=15) and normal oral mucosa (n=10). The cellular localization of immunostain, intensity of stain, mean nuclear labeling index (LI) and mean nuclear labeling score (LS) of hTERT protein were studied. A total number of 1000 cells were counted in each slide. All the data were analyzed using SPSS software version 10.0.2. The cellular localization of cytoplasmic/nuclear/both of hTERT stain, staining intensity and LI were compared across the groups using Pearson's χ2 test. The mean LI and LS for OSF, leukoplakia, OSCC and normal were compared using analysis of variance (ANOVA). A P-value <0.05 was considered to be statistically significant. Results: The mean nuclear LI increased from OSF (22.46±4.53), through normal (28.3±12.3) to OSCC (47.56±21.30) (P=0.002) and from normal (28.3±12.3), through leukoplakia (44.06±14.6), to OSCC (47.56±21.30) (P=0.00). The mean nuclear labeling score was observed to increase from OSF (37.8±15), through normal (64.9±30.7), to OSCC samples (106.9±29.77) (P=0.00) and from normal (64.9±30.7), through leukoplakia (85.6±25.1) to OSCC samples (106.9±29.77) (P=0.00). Conclusion: There was increased expression of hTERT protein in OSCC and leukoplakia samples when compared to normal oral mucosa. The cellular localization, LI and LS in OSF were significantly different from OSCC and leukoplakia.

in vitro evaluation of marginal leakage using invasive and noninvasive technique of light cure glass ionomer and flowable polyacid modified composite resin used as pit and fissure sealant.

Aim: This study compared the microleakage of light cure glass ionomer and flowable compomer as pit and fissure sealant, with and without tooth preparation. Materials and Methods: One hundred premolars that were extracted for orthodontic purpose were used. After adequate storage and surface debridement, the teeth were randomly divided into four groups. In Group I and III, the occlusal surfaces were left intact, while in Group II and Group IV, tooth surfaces were prepared. Teeth in Group I and Group II were sealed with Light cure glass ionomer, whereas flowable compomer was used to seal teeth in Group III and IV. The sealed teeth were then immersed in dye. Subsequently, buccolingual sections were made and each section was examined under stereomicroscope for microleakage followed by scoring. Results: In group I, microleakage score ranged from 2 to 4 with mean of 3.64 (±0.757), while in group II the range was observed to be 1-4 with mean of 2.88 (±1.236). Group III recorded a range of 0-4 with the mean of 2.20 (±1.443) while 0-2 and 0.60 (±0.707) being the range and mean observed, respectively, for group IV. Conclusion: Flowable compomer placed after tooth preparation showed better penetration and less marginal leakage than the light cure glass ionomer.

Effect of ProRoot MTA, Portland cement, and amalgam on the expression of fibronectin, collagen I, and TGFβ by human periodontal ligament fibroblasts in vitro.

Context: Today many materials have been introduced for root-end filling materials. One of them is mineral trioxide aggregate (MTA) that is mentioned as a gold standard. Aims: The purpose of this in vitro study was to evaluate the reaction of human periodontal ligament fibroblasts to the root-end filling materials, such as ProRoot MTA, Portland cement, and amalgam. Settings and Design: Eight impacted teeth were extracted in aseptic condition. The tissues around the roots were used to obtain fibroblast cells. After cell proliferation, they were cultured in the chamber slides and the extracts of the materials were added to the wells. Materials and Methods: Immunocytochemical method for measuring the expression of Fibronectin, collagen I and transforming growth factor beta (TGF®) was performed by Olysia Bioreport Imaging Software. Statistical Analysis Used: The results were analyzed by SPSS 13.0 and Tukey post hoc test with P<0.05 as the limit of significance. Results: Collagen expression in MTA specimens was higher than the other groups in 24 h significantly. After 48 h, the Portland cement group showed the most expression of collagen significantly and after 1 week, Portland cement and MTA groups had the most expression of collagen but there was no significant difference between these 2 groups. After 1 week, the Portland cement group demonstrated a higher amount of TGF® and fibronectin. Conclusions: The results suggest that Portland cement can be used as a less expensive root filling material with low toxicity. It has better effects than amalgam on the fibroblasts.

Morphology of collagen fibers and elastic system fibers in actinic cheilitis.

Background: Actinic cheilitis (AC) is a premalignant condition intimately related to exposure of the lips to sun rays. Aim: The objective of this study was to evaluate the elastic and collagen fibers in the lamina propria of AC. The degree of epithelial atypia was correlated with the quantity of elastic and collagen fibers. Materials and Methods: Fifty-one cases were investigated. One slide was stained with hematoxylin-eosin for the evaluation of atypia, the second was stained with Weigert's resorcin-fuchsin for the assessment of elastic fibers, and the third slide was stained with Mallory's trichrome for the analysis of collagen fibers. Results: Ordinal logistic regression analysis revealed a significant correlation between the presence of atypia and collagen fibers (P<0.05). Conclusions: It was concluded that there seems to be a reduction in the quantity of collagen fibers in cases of moderate and severe atypia. No correlation was observed between the degradation of elastic system fibers and the grade of dysplasia.

Diagnostic efficiency of toluidine blue with Lugol's iodine in oral premalignant and malignant lesions.

Background and Objectives: In vivo stains are prompt resources, which have emerged, in the recent years, to aid as clinical diagnostic tools in detecting early premalignant and malignant lesions. The aim of the study was to determine the diagnostic efficiency of toluidine blue with Lugol's iodine in oral premalignancies and malignancies and to evaluate the reliability of in vivo staining with toluidine blue and Lugol's iodine in the lesions at risk of malignancy. Materials and Methods: The study group comprised 30 subjects with clinically suspicious premalignant lesions and 30 subjects with clinically suspicious malignant lesions. All the lesions were stained consecutively with toluidine blue and Lugol's iodine and the dye retention were recorded with photographs. Depending on the retention of the dyes, the biopsy site was determined. The biopsy specimens were sent for histological confirmation and results were statistically analyzed. Results: The overall diagnostic accuracy of Lugol's iodine when used consecutively with toluidine blue stain in distinguishing premalignant lesions and malignant lesions was 90%. As the degree of differentiation of malignant lesions progressed toward more severity, they failed to show the retention of Lugol's iodine and the result was highly significant statistically, with a P value < 0.001. Interpretation and Conclusion: Lugol's iodine when used with toluidine blue helped in delineating the inflammatory lesions and was the mean source in determining clinically the degrees of differentiation of malignant lesions as the poorly differentiated malignant lesions without glycogen content failed to show Lugol's iodine retention. Toluidine blue with Lugol's iodine can be used as a pretherapeutic assessment of the biologic aggressiveness of the disease.

Relationship between the size of patency file and apical extrusion of sodium hypochlorite.

Background: Sodium hypochlorite (NaOCl) is the most widely used endodontic irrigant because of its excellent antimicrobial, organic tissue dissolving, and lubricating properties. However, it is highly cytotoxic to the periapical tissues. Aim: This study evaluated in vitro the extrusion of 5.25% NaOCl through the apical foramina of mesiobuccal (MB) root canals of maxillary first molars in two experimental conditions: Before apical debridement and after apical debridement with different instrument sizes to ensure direct access to the apical foramen (apical patency). Materials and Methods: Coronal accesses were prepared in 17 teeth and the apical foramina of the distobuccal and palatal root canals were sealed. The teeth were held in acrylic receptacles with the roots turned upwards to reproduce their position in the maxillary dental arch. The receptacles were filled with a starch/KI solution (a reagent that changes its color to blue after contacting NaOCl) covering the roots. The experiment had two phases: P1: Irrigation of the MB canals with 5.25% NaOCl without previous establishment of apical patency; P2: Canal irrigation after use of size 10 K-file and size 15 Flexofile as patency files. Only specimens with no NaOCl extrusion in P1 were assigned to P2. NaOCl was delivered pressureless at the canal entrance. The moment that the starch/KI solution contacted NaOCl was captured on digital photographs. Results and Conclusions: There was no NaOCl extrusion in nine specimens in P1, but all of these teeth had irrigant extrusion in P2. The 5.25% NaOCl used as an endodontic irrigant showed great capacity to extrude beyond both intact and small-sized apical foramina of MB root canals of maxillary first molars.

Cytotoxicity evaluation of Persica mouthwash on cultured human and mouse cell lines in the presence and absence of fetal calf serum.

Background and Aims: The effectiveness of an ideal antimicrobial agent depends on its ability to kill microbes while causing minimal toxicity to host cells. Several studies have been reported on the antimicrobial effects of chewing sticks (Salvadora persica) on oral bacteria. The purpose of this study was to evaluate the cytotoxic effects of Persica™ and chlorhexidine (CHX) mouthwashes on cultured human and mouse cell lines. Materials and Methods: This was an experimental study. The toxic effects of four dilutions of Persica™ and CHX mouthwashes on KB, Saos-2, J744 A1, and gingival fibroblast cells were evaluated by MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide] assay. The effect of fetal calf serum (FCS) components on the cytotoxicity of these mouthwashes was also investigated. Statistical Analysis: Analysis of variance and the Kruskal-Wallis test were used to evaluate the results. Results: The results indicated that Persica™, at concentrations higher than 0.1%, exerted a very significant cytotoxic effect on all the cell lines (P < 0.01). CHX, at a concentration of 0.001%, exerted toxic effects only on gingival fibroblasts; concentrations higher than 0.001% were required to produce significant cell death in the other cell lines. At all the concentrations under study, both Persica™ and CHX exerted significantly greater cytotoxic effects in the absence of FCS than in its presence (i.e., in control culture medium). The toxicities of both mouthwashes were attenuated in the presence of FCS (10%). Conclusion: Our results indicate that both Persica™ and CHX mouthwashes are toxic to macrophage, epithelial, fibroblast, and osteoblast cells in a concentration-dependent manner.

Influence of flowable materials on microleakage of nanofilled and hybrid Class II composite restorations with LED and QTH LCUs.

Background: Class II composite restorations are more frequently being placed with margins apical to the cementoenamel junction (CEJ) and margins within the dentin are prone to microleakage. Aims: This in vitro study was used to evaluate the influence of flowable composite and flowable compomer as gingival liner on microleakage in Class II composite restorations and compare a light-emitting diode (LED) unit with a quartz tungsten halogen (QTH) unit for light-activating composite resins. Materials and Methods: Mesioocclusal and distoocclusal Class II cavity preparations were made in 72 sound extracted premolars. The buccolingual width was 2.5 mm and the gingival margins of all the cavities were placed 1.0 mm apical to the CEJ. The boxes were prepared 1.5 mm deep axially, making 144 slot cavities. Teeth were randomly divided into the following two groups (n = 72): (I) Universal Filtek Supreme XT; Universal Filtek Supreme XT + Flwable Filtek XT and Universal Filtek Supreme XT + Dyract Flow and (II) Filtek Z250; Filtek Z250 + Flwable Filtek XT and Filtek Z250 + Dyract Flow. Flowable materials were injected into the gingival floor of the cavity to a thickness of 1.0 mm. Each increment was cured for 20 s. One-half of the subgroups in each group were cured with QTH and the other half with LED light curing units (LCUs). After 1 week of incubation at 37°C, the specimens were thermocycled (5-55°C, x1500), immersed in 0.5% basic fuchsine dye for 24 h and sectioned and microleakage was evaluated at the gingival margin by two examiners using a 0-3 score scale. The data were analyzed using the Kruskal-Wallis and Mann-Whitney U tests. Results: The groups utilizing flowable liners had significantly less microleakage (P < 0.05). No significant difference was identified between Universal Filtek Supreme XT and Filtek Z250 composites with and without flowable materials. There was no significant between utilizing flowable composite or flowable compomer and between each similar subgroup when polymerized with either the LED or the QTH LCUs. Conclusions: A layer of flowable materials at the gingival floor of Class II composite restorations may be recommended to improve the marginal seal of a restoration.