Comparision of two different preparation protocol of Ni-Ti Rotary PathFile-ProTaper instruments in simulated s-shaped canals.

INTRODUCTION: The aim of this study is to compare the root canal transportation with the PathFile-ProTaper recommended protocol, PathFile-ProTaper modified protocol and stainless steel K-flexofiles. METHODS: Forty-five ISO 15, 0.02 taper S-shaped Endo Training Blocks were divided randomly into three groups of 15 each and prepared as follows: PathFile-Protaper recommended protocol, Pathfile-Protaper modified protocol and manual preparation with K-Flexofiles. The amount of transportation was assessed by scanning the blocks before and after preparation and superimposing the images. The cutting effects of the instruments from the inner and outer aspects of the root canals were measured and statistically analyzed with the One-way Anova test and Tukey HSD test. RESULTS: Manual preparation caused significantly more transportation than both PathFile-Protaper systems. There was no significant difference regarding transportation between the two Pathfile-Protaper protocols. CONCLUSION: The modified Pathfile-Protaper protocol transported the canal similar to the recommended Pathfile-Protaper protocol. It may be suggested that, while working safety remains unchanged, the shaping procedure and consequently working time can be shortened with fewer instruments. The results of this study can help clinicians to reduce the preparation time with the PathFile-ProTaper rotary system while the preparation quality remains the same.

Human tooth germ stem cell response to calcium-silicate based endodontic cements.

OBJECTIVE: The aim of this study was to compare the cytotoxic effects of endodontic cements on human tooth germ stem cells (hTGSCs). MTA Fillapex, a mineral trioxide aggregate (MTA)-based, salicylate resin containing root canal sealer, was compared with iRoot SP, a bioceramic sealer, and AH Plus Jet, an epoxy resin-based root canal sealer. MATERIAL AND METHODS: To evaluate cytotoxicity, all materials were packed into Teflon rings (4 mmµ3 mm) and co-cultured with hTGSCs with the aid of 24-well Transwell permeable supports, which had a pore size of 0.4 µm. Coverslips were coated with MTA Fillapex, iRoot SP and AH Plus Jet and each coverslip was placed onto the bottom of one well of a six-well plate for scanning electron microscopy (SEM) analysis. Before the cytotoxicity and SEM analysis, all samples were stored at 37ºC and at 95% humidity and 5% CO2 for 24 hours to set. The cellular viability was analyzed using MTS test (3-(4,5-dimethyl-thiazol-2-yl)-5-(3-carboxy-methoxy-phenyl)-2-(4-sulfo-phenyl)-2H-tetrazolium). The cytotoxic effects and SEM visualization of the tested materials were analyzed at 24-hour, 72-hour, one-week and two-week periods. RESULTS: On the 1st day, only MTA Fillapex caused cytotoxicity compared to negative control (NC) group (p<0.008). No significant difference was observed between the other tested materials at this period (p>0.05). After 14 days of incubation with the test materials, MTA Fillapex exhibited significantly higher cytotoxicity compared with iRoot SP, AH Plus Jet and the NC group (P<0.008). In the SEM analysis, the highest levels of cell attachment were observed for iRoot SP and the control group. After 24 hours, MTA Fillapex reduced the number of cells attached to the surface. CONCLUSIONS: Within the limitations of this study, sealers exerted different cytotoxic effects on hTGSCs. Although all materials have exerted cellular toxicity, iRoot SP and AH Plus Jet may promote better attachment to hTGSCs.

Human tooth germ stem cell response to calcium-silicate based endodontic cements

OBJECTIVE: The aim of this study was to compare the cytotoxic effects of endodontic cements on human tooth germ stem cells (hTGSCs). MTA Fillapex, a mineral trioxide aggregate (MTA)-based, salicylate resin containing root canal sealer, was compared with iRoot SP, a bioceramic sealer, and AH Plus Jet, an epoxy resin-based root canal sealer. MATERIAL AND METHODS: To evaluate cytotoxicity, all materials were packed into Teflon rings (4 mmµ3 mm) and co-cultured with hTGSCs with the aid of 24-well Transwell permeable supports, which had a pore size of 0.4 µm. Coverslips were coated with MTA Fillapex, iRoot SP and AH Plus Jet and each coverslip was placed onto the bottom of one well of a six-well plate for scanning electron microscopy (SEM) analysis. Before the cytotoxicity and SEM analysis, all samples were stored at 37ºC and at 95% humidity and 5% CO2 for 24 hours to set. The cellular viability was analyzed using MTS test (3-(4,5-dimethyl-thiazol-2-yl)-5-(3-carboxy-methoxy-phenyl)-2-(4-sulfo-phenyl)-2H-tetrazolium). The cytotoxic effects and SEM visualization of the tested materials were analyzed at 24-hour, 72-hour, one-week and two-week periods. RESULTS: On the 1st day, only MTA Fillapex caused cytotoxicity compared to negative control (NC) group (p<0.008). No significant difference was observed between the other tested materials at this period (p>0.05). After 14 days of incubation with the test materials, MTA Fillapex exhibited significantly higher cytotoxicity compared with iRoot SP, AH Plus Jet and the NC group (P<0.008). In the SEM analysis, the highest levels of cell attachment were observed for iRoot SP and the control group. After 24 hours, MTA Fillapex reduced the number of cells attached to the surface. CONCLUSIONS: Within the limitations of this study, sealers exerted different cytotoxic effects on hTGSCs. Although all materials ...

Cross-sectional evaluation of post-operative pain and flare-ups in endodontic treatments using a type of rotary instruments.

AIM: The purpose of this clinical study was to evaluate the general incidence of post-operative pain and flare-ups in patients who were endodontically treated by two endodontics specialists using rotary instruments (Hero 642, Micro Mega, France) with the same treatment protocol. METHODS: Records of 382 teeth belonging to 268 patients treated by two endodontics specialists during a 6-month period were kept and evaluated. Post-operative pain between treatment visits was categorized using a pre-established scoring system. Ninety-five patients were males, whereas 173 were females. RESULTS: Pulpal necrosis without periapical pathosis was determined as the most common indication for endodontic treatment (21.7%) followed by irreversible pulpitis and re-treatment without periapical lesions (18.3%, 18.3%, respectively). The general prevalence of post-operative pain and flare-ups was determined as 8.1%, whereas cases that could be classified as real flare-ups which were severe and required an unscheduled visit (scores 2 and 3) comprised 3.4% of the cases. No statistically significant correlation was determined between gender and post-operative pain and flare-up (p = 0.05). There was a significant correlation between number of appointments and the presence of pain and flare-ups. Teeth undergoing multiple visits had a higher risk of developing post-operative pain and flare-ups compared to those with single appointments with a statistical significance (p = 0.03). CONCLUSIONS: Teeth with pre-operative pain were more prone to developing post-operative pain and discomfort with a statistically significant difference (p = 0.02). While no significant correlation was determined between tooth vitality and pain and flare-ups (p = 0.5), a statistically significant relationship existed between the presence of a periapical pathosis and post-operative pain and flare-ups. Cases with a periapical lesion had a higher risk of developing pain and flare-ups compared to those with no periapical involvement (p = 0.0001). Future studies may focus on the influence of rotary instrumentation systems in more specific groups of cases. Meanwhile; microbiological as well as psychological aspects of flare-ups are topics that warrant further investigation.

The status of mineral trioxide aggregate in endodontics education in dental schools in Turkey.

The aim of this study was to assess the current status of mineral trioxide aggregate (MTA) as an educational material in dental schools in Turkey. A survey was sent to senior members of the endodontic departments of seventeen dental schools; fourteen responded. All respondents reported that they used MTA in their clinical practice, with apexification, perforations, retrograde fillings, and root resorptions being the most frequently occurring treatment procedures. All reported that information was given to students regarding MTA mainly as part of the curriculum. The third and fourth years were the periods when MTA was introduced to students in most of the schools. Twelve schools reported that students had the opportunity to observe procedures in which MTA was used, but students had the chance to use the material in a very minor proportion of the schools, mainly under the supervision of clinical instructors. Ten schools agreed that MTA should be included in the regular endodontic curriculum. Financial constraints seemed to be the predominant reason for those who answered this question negatively, followed by difficult handling properties and low radiopacity of the material. Within the limitations of this study, it can be concluded that ways should be sought to prevent financial difficulties from depriving dental students of the opportunity to receive information about contemporary methodologies such as MTA utilization.

Potential of an Er:YAG laser in the removal of calcium hydroxide from root canals.

OBJECTIVE: The purpose of this study was to assess the calcium hydroxide (CH) removal potential of an Er:YAG laser in combination with ethylenediaminetetraacetic acid (EDTA) and sodium hypochlorite (NaOCl) irrigation. BACKGROUND DATA: Removal of the CH dressing prior to the root canal filling is mandatory, as its remnants may mechanically block the apical area of the root canal system and also have an effect on the texture, viscosity, working time, penetration, and adhesion of root canal sealers. However, the removal of CH from the canal space is challenging, because it should ideally be placed deep and densely, so that its biological effects can be exerted in close proximity to the appropriate tissues. METHODS: In this study, the mandibular premolar teeth were embedded in acrylic blocks and sectioned longitudinally through the canal, forming two halves following shaping of the root canals with ProTaper (Maillefer, Ballaigues, Switzerland) rotary instruments. The teeth were reassembled after standard grooves created onto canal walls were filled with CH. In group 1, conventional irrigation was performed with 10 mL of 17% EDTA and 10 mL of 5% NaOCl, and in goup 2, Er:YAG laser following conventional irrigation was performed. Images of the grooves taken before and after irrigation were scored and the Mann-Whitney U test was used to statistically evaluate the results. RESULTS: The percentage of CH score reduction was 46.30% in group 1 and 60.58% in group 2. No significant difference was found between two groups (p>0.05). CONCLUSIONS: The laser did not improve the removal of CH during conventional root canal irrigation performed with NaOCl and EDTA under the conditions of current study.

Comparison of the fracture resistance of simulated immature permanent teeth using various canal filling materials and fiber posts.

BACKGROUND: The purpose of this study was to compare the fracture resistances of immature teeth treated with MTA along with root canal obturation methods using AH Plus, MetaSEAL, MTA Fillapex sealers + lateral compaction technique, and Unicore quartz fiber posts. MATERIALS AND METHODS: Fifty single-rooted maxillary anterior teeth were divided into five groups. The crowns were dissected and root canals were enlarged. #6 Peeso reamers were allowed to protrude 1 mm. beyond the apex to simulate immature teeth. The apical 4-5 mm of each tooth was filled using Angelus white MTA. The remaining portions of canals were obturated as follows: Group 1: No backfilling (control), Group 2: AH Plus + gutta-percha, lateral compaction, Group 3: MetaSEAL + gutta-percha, lateral compaction, Group 4: MTA Fillapex + gutta-percha, lateral compaction, Group 5: UniCore Fiber posts luted using PermaFlo DC. The specimens were embedded into self-curing acrylic poured into identical cylinders which were mounted on a jig providing a 45° angle. A compressive load increasing at 1 mm min(-1) was applied and the maximum load at which fracture occurred was recorded. Statistical analysis was performed using Kruskal-Wallis and Dunn's multiple tests. RESULTS: The highest fracture resistance was obtained with Group 5 (Fiber posts) whereas Group 4 (MTA Fillapex) yielded the lowest values. The mean fracture resistance value of Group 2 (AH Plus) was significantly higher than Group 4 (MTA Fillapex) (P = 0.001). The mean fracture value of Group 5 (Fiber posts) was significantly higher than Group 2 (AH Plus), Group 3 (MetaSEAL), and Group 4 (MTA Fillapex) (P = 0.02, 0.004, and 0.0001, respectively). CONCLUSION: Within the limitations of this study, UniCore quartz fiber posts provided the highest resistance. This methodology may specifically be advantageous for teeth with arrest of development at early stages, as these teeth are more susceptible to fracture owing to their excessively weak dentinal walls.

Effect of dental materials calcium hydroxide-containing cement, mineral trioxide aggregate, and enamel matrix derivative on proliferation and differentiation of human tooth germ stem cells.

INTRODUCTION: Biocompatibility of pulp capping materials is important for successful use in dentistry. These materials should be nontoxic and permissive for proliferation and induction of odontogenic differentiation of pulp cells. The aim of our study was to evaluate the effects of enamel matrix derivative (EMD), mineral trioxide aggregate (MTA), and calcium hydroxide-containing cement (DYCAL) on proliferation and odontogenic differentiation of human tooth germ stem cells (hTGSCs) in which cells belonging to both pulp tissue and dental follicle exist. METHODS: The 96-well plates, 24-well plates, and special chamber slides were coated with biomaterials for cell proliferation, differentiation, and scanning electron microscopy analysis. Odontogenic differentiation of hTGSCs was evaluated by analyzing mRNA expression of dentin sialophosphoprotein (DSPP) by real-time polymerase chain reaction expression analysis, measurement of alkaline phosphatase activity, and visualization of calcium depositions by von Kossa staining. RESULTS: Our results demonstrate that EMD is the best material in terms of inducing differentiation and proliferation of hTGSCs. DYCAL was found to be toxic to hTGSCs; however, EMD-coated DYCAL showed less toxicity. EMD-coated MTA was not efficient at inducing proliferation and differentiation. CONCLUSIONS: Pulp capping materials come in direct contact with dental pulp cells; thus, they require comprehensive evaluation of interactions between cells and biomaterials. Therefore, we cultured hTGSCs, capable of odontogenic differentiation, on pulp capping materials directly. Our results suggest that combination of capping materials with EMD would increase the quality of capping by increasing biocompatibility of capping materials.

The effect of the gap between the post restoration and the remaining root canal filling on the periradicular status in a Turkish subpopulation.

OBJECTIVE: The aim of this study was to evaluate whether the gap between the post restoration and the remaining root canal filling had an impact on the periapical health of endodontically treated teeth in a Turkish subpopulation. STUDY DESIGN: Digital panoramic radiographs, evaluated for this cross-sectional study, were randomly selected from files of patients who attended to Yeditepe University, Faculty of Dentistry, between June 2007 and December 2008. The total number of teeth with endodontic posts and crowns was 407. Two observers assessed the radiographs and evaluated the quality of root canal filling and the gap between the root canal filling and the post restoration. Periapical status of the teeth was assessed by the Periapical Index (PAI) scores. Only the teeth with a minimum of 5 mm apical root canal filling that was classified as "good endodontic treatment" were included in the study. Teeth that had no root canal filling, poor endodontic treatment, or less than 5 mm remaining root canal filling beyond post restoration were not assessed. Chi-square test was used for statistical analysis and significance level was established at 5%. RESULTS: In cases with good endodontic treatment, there were 207 teeth that had no gap between the remaining root canal filling and the post restoration. In this group, 135 (65%) teeth had healthy periapex and 72 (35%) teeth showed signs of apical periodontitis. There were 81 teeth that had a gap between the remaining root canal filling and the post restoration. Of these teeth, 69 (85%) had periapical pathosis; however, only 12 (15%) teeth had healthy periapex. CONCLUSION: Statistical analysis revealed that the success rate of good endodontic treatment was significantly affected by the gap between the post restoration and remaining root canal filling (P < .001).

Microleakage of various root filling systems by glucose filtration analysis.

OBJECTIVE: The aim of this study was to evaluate the microleakage of Resilon + Epiphany, EndoRez, Activ GP, and conventional AH Plus + gutta-percha technique using the glucose filtration model. STUDY DESIGN: One hundred twenty maxillary incisors were divided into 5 experimental and 2 control groups. After root canal shaping, the experimental groups were filled with AH Plus + gutta-percha (lateral compaction), Resilon + Epiphany (lateral compaction), AH Plus + Protaper's proprietory cone, EndoRez + sealer, or Activ GP + sealer). The specimens were mounted on a glucose model and samples were taken for 3 weeks for leakage measurement. RESULTS: No statistically significant difference was observed between the leakage of all groups at the 3 testing periods (P > .05). CONCLUSION: The filling materials with the monoblock concept do not seem to be superior to the conventional AH Plus + gutta-percha system regarding microleakage.

Diagnosis of jaw and dentoalveolar fractures in a traumatized patient with cone beam computed tomography.

The purpose of this case report is to discuss and illustrate the clinical usage of Cone Beam Computed Tomography (CBCT) for the diagnosis of maxillofacial fractures in a traumatized patient. In this presentation, a 30-year-old male patient who was referred to Oral Diagnosis and Radiology Department with a limitation of mouth opening was reported. The history of the patient revealed a traumatic injury on his face because of a fall. The patient was initially examined by a medical practitioner in the emergency department of a public hospital. According to 2D cephalometric analysis, no fracture existed. Panoramic radiograph and postero-anterior reverse-town showed bilateral condyle fractures. In addition, a fracture in the left mandibular incisor region could clearly be detected on the panoramic radiograph. For further diagnosis, digital images were taken with CBCT. Cross-sectional views showed two vertical fracture lines on the alveolar bone between teeth numbers 17, 18 and 14, 15. A palatal root fracture was observed associated with tooth number 18. A fracture line in the left mandibular incisor region as well as bilateral condyle fractures could be seen clearly on CBCT views. CBCT is becoming a popular tool in modern dental practise. In the diagnosis of dentoalveolar fractures, CBCT has made it possible for the practitioner to get more detailed information.

The effect of endodontic irrigants on the microtensile bond strength of dentin adhesives.

INTRODUCTION: The purpose of this study was to evaluate the microtensile bond strength of a total etch (XP-Bond) and a self-etch (Clearfil SE Bond) adhesive system to dentine surfaces treated using endodontic irrigants. METHODS: Twenty-four freshly extracted third molars were used. After creating a smear layer on the coronal midthird portion of the crowns, the teeth were divided into three groups and surfaces were irrigated with distilled water, 5.25% NaOCl + 17% EDTA, and 1.3% NaOCl + BioPure MTAD, respectively. Each group was divided into two subgroups, and a self-etching adhesive and an etch-and-rinse adhesive were applied respectively. The teeth were restored with a composite material and sectioned to produce sticks for microtensile bond testing. RESULTS: The microtensile bond strength of the MTAD + Clearfil SE group was found to be significantly lower than the microtensile bond strength of the distilled water + Clearfil SE Bond group and the NaOCl, EDTA, + Clearfil SE Bond group (p = 0.0001, p = 0.009). CONCLUSIONS: Because of the significant reduction of Clearfil SE Bond to coronal dentine after MTAD application, an etch-and rinse adhesive such as XP-Bond may be preferred if this irrigant has been chosen during endodontic treatment.

Detection of artificial occlusal caries in a phosphor imaging plate system with two types of LCD monitors versus three different films.

The aim of this study was to determine diagnostic performance of a storage phosphor plate system Digora Optime (Soredex, Helsinki, Finland) with two types of LCD monitor in the detection of artificial caries when compared to Ultraspeed (D), Ektaspeed Plus (E), and Insight (F) radiographic films. Seventy extracted human molars-with artificial caries-were radiographed under identical standardized conditions using (1) a storage phosphor plate system Digora (Soredex, Helsinki, Finland), (2) Insight, (3) Ektaspeed Plus, and (4) Ultraspeed (Carestream Health Inc, Rochester, NY). All digital images and radiographs were examined by three observers for the presence or absence of artificial caries using a five-point confidence scale. Digital images were evaluated both on a LCD computer monitor (Philips 170S, Holland) and medical monitor-3 megapixel monochrome display (Me355i2, Totoku, Tokyo)-with brightness and contrast enhancement. Observer responses were evaluated using ROC analysis and other measurements for diagnostic accuracy. Storage phosphor images with medical monitor demonstrated higher mean A (z) values (0.70 +/- 0.08) than digital images with computer monitor and conventional films. Storage phosphor images with medical monitor presented the highest score, 0.97, 0.90, 0.94, for each observer, respectively. Also, true positive observations (0.82) and positive likelihood ratios (2.71) were higher in enhanced storage phosphor images with medical monitor. Caries detection of mechanically created lesions by experienced radiologists is roughly comparable when examining D-speed film images and Digora images on both the computer and medical LCD monitors, and appears to be poorer on E- and F-speed film images.

Two-year follow-up of fractured anterior teeth restored with direct composite resin: report of three cases.

Thirty-five (case 1), 15 (case 2) and 22 (case 3)-year-old female patients presented to Yeditepe University Dental Faculty Clinic because of esthetic reasons. Fractures of maxillar central incisors including enamel and dentin were diagnosed. Beveling with diamond bur was performed in all four cases. Dentin was cleaned with tungsten carbid bur. The teeth were etched with 37% phosphoric acid, restored with an adhesive system and microhybrid composite. Finishing and polishing procedures were performed by discs (Sof-Lex) and burs. Restorations were found successful according to modified United States Public Health Service (USPHS) criteria after 2 years in terms of retention, color match, marginal discoloration, secondary caries, marginal adaptation, and surface texture.

Periapical health related to the type of coronal restorations and quality of root canal fillings in a Turkish subpopulation.

OBJECTIVE: The purpose of this study was to evaluate the relationship between the quality of root canal fillings and type of permanent coronal restorations and their association with the periapical status in a Turkish subpopulation. STUDY DESIGN: There were 1268 endodontically treated teeth from 280 panoramic radiographs that were evaluated. Two observers assessed the radiographs using an x-ray viewer with 2 times magnification. Teeth were classified according to the type of restorations. The quality of root canal fillings were evaluated according to the criteria determined by Tronstad et al. Apical status was assessed by the Periapical Index scores (PAI) proposed by Ørstavik et al. Chi-square test was used for statistical analysis. RESULTS: There were 59.5% of endodontically treated teeth that showed healthy periapex. Teeth with good endodontic treatment showed statistically significant high healthy periapex rates regardless of the type of the restoration. In addition, the evaluation of the entire material also showed that the roots with posts had significantly more periapical pathosis than roots without posts (P = .001). CONCLUSIONS: It can be concluded that, although the quality of the root canal filling plays a key role in the outcome of endodontic therapy, the type of restoration can also be a contributing factor in the treatment outcome.

Dental lesions in adult diabetic patients.

The aim of this study was to investigate the number of existing teeth, prevalence of endodontically treated teeth, periapical lesions, caries and restorations in diabetic patients by taking periapical radiographs. Forty-six patients with Type I diabetes and 40 patients with Type II diabetes participated in the study. The control group consisted of 50 patients. There were significant differences between patients with Type I and Type II diabetes in the mean number of missing teeth surfaces and existing teeth.

Persistent sinus tract formation 1 year following cast post-and-core replacements: a case report.

Sinus tracts are paths of drainage for abscesses and can occur both intraorally and extraorally. It is a fact that sinus tracts can heal with proper endodontic therapy. However, there are those types that are persistent and will not respond to any treatment. In these perplexing cases, it may be necessary to elevate a surgical flap to unveil the real etiologic factor. In this article, a case is presented in which 2 persistent and nonhealing sinus tracts were observed around the maxillary left incisor area of a 53-year-old female patient. A difficult cast post-and-core removal had been accomplished to the compromised tooth 1 year previously. A surgical flap had to be reflected, and the cause of the persistent inflammation was determined to be 2 separate root perforations. The granulation tissue was removed, the perforations were sealed with mineral trioxide aggregate, and bone graft was packed in the resorptive bone areas. The symptoms subsided by the time of the 2-week recall. No complaints were noted from the patient during the 4-month follow-up period. This case is a good example that demonstrates the possible complications of post preparation and the necessity of explorative surgery for unveiling the etiologic factor of persistent sinus tract formation.

Clinical evaluation of posterior composite restorations in endodontically treated teeth.

OBJECTIVE: The purpose of this study was to evaluate the two year clinical performance of posterior composite restorations in endodontically treated premolars and molars using a hybrid composite (Filtek Z-250, 3M ESPE) and a total etch bonding system (Single Bond, 3M ESPE). METHOD AND MATERIALS: Thirty-nine class II restorations in endodontically treated premolars (n=11) and molars (n=28) of 27 patients (14 female, 13 male, mean age 36.51) in 16 maxillar and 23 mandibular teeth were placed by one operator. Restorations were evaluated by two experienced investigators at baseline, 12 months, and 24 months according to the modified United States Public Health Service (USPHS) criteria that included retention, color match, marginal discoloration, secondary caries, anatomic form, marginal adaptation, and surface texture. All restorations were able to be evaluated at baseline, 12 months, and 24 months. RESULTS: Paired samples t-test showed only marginal discoloration showed a statistically significant difference (p<0.05) at the end of 24 months, and no other significant differences were observed for the other variables examined over the duration of the study. None of the restored teeth showed periapical pathology at the end of 24 months. CONCLUSION: At two years, limited deterioration in marginal discoloration was detected. The clinical performance of posterior composite restorations in endodontically treated teeth using Filtek Z250 was found clinically acceptable after two years.

Prevalence of the patients with history of hepatitis in a dental facility.

OBJECTIVES: The aim of the study is to investigate the prevalence of the dental patients who had a history of hepatitis. STUDY DESIGN: A total of 13.527 records of patients who were examined between October 1, 2002 and October 1, 2004 were reviewed retrospectively. The medical histories of patients were taken before routine clinical and radiographic examination. A dental software program was used for the collection of data. The chi-square test was utilized to evaluate correlations between different parameters. RESULTS: The percentage of the patients who had a medical history of hepatitis was 7.9% (n=1065). Within the total patients; history of hepatitis A was found as 3.2% (n=438), hepatitis B was 2.3% (n=308), hepatitis C was 0.1% (n=16). The frequency of the patients who were hepatitis B carriers was 0.8% (n=113) and 17% (n=181) of patients did not know which type of hepatitis they had suffered from. CONCLUSIONS: Because dentists are particularly at risk for contacting hepatitis, a strict sterilization procedure is mandatory to prevent the transmission.

Comparative evaluation of the preparation efficacies of HERO Shaper and Nitiflex root canal instruments in curved root canals.

OBJECTIVES: To comparatively evaluate the shaping efficacies of HERO Shaper rotary instruments and Nitiflex hand files. STUDY DESIGN: The mesial roots of 40 mandibular molars were used. In 20 teeth, the mesiobuccal canals were instrumented with HERO Shaper and the mesiolingual canals with Nitiflex. In the remaining 20 teeth, the mesiobuccal canals were instrumented with Nitiflex and the mesiolingual canals with HERO Shaper. Pre- and postoperative sections were obtained from the coronal, middle, and apical portions and analyzed. Statistical analysis was performed using the Student t test. RESULTS: More dentin was removed from the middle portion with HERO Shaper (P < .05). No statistically significant difference was observed in terms of transportation (P>.05). No instrument fracture or deformation was noted. CONCLUSIONS: Both HERO Shaper and Nitiflex can be recommended for clinical practice. Further studies can focus on the comparison of HERO Shaper with other rotary instruments as there is an increasing trend for the utilization of these systems.