Radiopacity of Posterior Restorative Materials: A Comparative In Vitro Study.

BACKGROUND: The objective was to investigate the radiopacity of 11 commercial posterior restorative materials by establishing their mean gray values (MGVs) and comparing them with dental hard tissues. METHODS AND MATERIALS: Five-disc specimens were prepared for each of the following materials: Cerasmart 270 CAD/CAM block A3LT (CS), Amalgam (A), Ketac Molar A3 (KM), Cention-N A2 (CN), G-aenial Universal Flo AO2 (GO2) and A2 (G2), Ever-X Flow Dentine (EXD) and Bulk (EXB) shades, Equia Forte HT Fil A2 (EF2) and A3 (EF3), and Equia Fil A3 (E3). Freshly extracted maxillary premolar teeth were used as a control. The MGVs of specimens and a 10-step aluminum stepwedge (Al) were measured with Adobe Photoshop. ANOVA and Dunnett T3 tests were used to assess the significance of the differences (α=0.05). RESULTS: Statistically significant differences were revealed between some of the groups. Amalgam had the highest radiopacity. The radiopacity of dentin and CS were close to that of 1 mm Al. G2, KM, GO2, EXB, and EXD showed higher mean radiopacity than dentin. Enamel had a radiopacity equivalent to 2 mm Al. CN, EF2, and E3 had higher mean radiopacity than enamel. CONCLUSIONS: All materials met the ISO requirements. Alkasite and reinforced glass ionomer restoratives demonstrated higher mean radiopacity than the posterior flowable composites. Material shades did not affect the radiopacity.

Evaluation of the effect of apical lesion on mucosal thickening and thickness of apical bone using limited cone-beam computed tomography.

OBJECTIVE: The purpose of this study was to evaluate the effect of periapical lesion size on the degree of mucosal thickening of maxillary sinus and thickness of apical bone using cone-beam computed tomography. MATERIALS AND METHODS: In Group 1 (teeth with apical lesions), diameter of apical lesion, width of apical bone, thickness of Schneiderian membrane; for Group 2 (teeth without apical lesions), width of apical bone in long axis of root and thickness of Schneiderian membrane were measured on coronal and sagittal images. RESULTS: Mann-Whitney U-test revealed no significant difference between two groups regarding mucosal thickening and apical bone measurements (P > 0.05). Wilcoxon signed-rank test showed no significant difference between the measurements in sagittal and coronal slices (P > 0.05). CONCLUSION: Results of the present study showed that Schneiderian membrane near the maxillary premolars and molars with apical lesions is not significantly thicker compared to teeth without apical lesions.

Efficacy of topical benzydamine hydrochloride gel on oral mucosal ulcers: an in vivo animal study.

The aim of this study was to investigate the effect of benzydamine hydrochloride bioadhesive gel on healing of oral mucosal ulceration in an animal model. For in vivo determination of the effects of the bioadhesive gel, 36 rabbits were separated into three groups: the first group was treated with the gel formulation without active agent, the second group with the gel formulation containing benzydamine, and the third group received no treatment. Clinical healing was established by measuring the area of the ulcer in each test group on days 3, 6, 9 and 12. Histological healing was determined on the same days. Benzydamine containing gel applications resulted in a decrease in the ulcer area in 12 days (p=0.000). Histological evaluation showed that the benzydamine group had a higher mean histological score than the base and the control groups during the whole test period, and the difference between the benzydamine group and the control group was significant (p=0.04). The bioadhesive gel formulation of benzydamine hydrochloride showed a statistically significant increased rate of mucosal repair in this experimental standard mucosal wound animal study. It is a candidate for the topical treatment of oral mucosal ulcerative lesions.

Molecular typing of Candida albicans strains isolated from denture wearers by repetitive sequence-based PCR.

Long-term use of prosthesis is the most important risk factor for the colonization of Candida species on the mucosal surfaces, which can lead to the development of denture-related stomatitis (DRS). Some individuals wearing prosthesis develop DRS and others do not. C. albicans strains isolated from both groups were genotypically compared. The purpose of this study was to determine whether the strain causing prosthesis stomatitis was different from the other strains genotypically. The study included 90 individuals wearing different prostheses and 20 control individuals with natural teeth. In the study 109 C. albicans strains were used which were isolated from the saliva samples and the mucosal surfaces of the tongues and palates of 51 individuals and then defined phenotypically. Phenotypic diagnosis of the isolates was genotypically verified by using species-specific PCR. For molecular typing, repetitive extragenic palindromic sequence polymerase chain reaction (REP-PCR) was employed. The results of the study revealed that REP-PCR had the capability to separate 109 C. albicans strains and six reference strains into 44 genotypes. Whereas C. albicans strains showed heterogenic distribution, C. albicans strains isolated from the individuals suffering from prosthesis stomatitis showed no specific genotypes. REP-PCR is a simple, fast and low-cost method and helped work on a great number of samples.

The utility of toluidine blue staining and brush cytology as adjuncts in clinical examination of suspicious oral mucosal lesions.

The objective of this study was to investigate the utility of toluidine blue and brush cytology in patients with clinically detected oral mucosal lesions. Clinical examination of 35 patients was completed before toluidine blue application, oral brush cytology and scalpel biopsy. Lesions were photographed before and after stain application; followed by brush cytology. All findings were compared with histopathologic results. Severe dysplasia and carcinoma-in-situ were determined as 'positive'; no dysplasia and mild to moderate dysplasia were defined as 'negative'. The sensitivity, specificity, positive and negative predictive values of clinical examination and toluidine blue were the same: 0.923, 0.433, 0.414, and 0.929, respectively. Those of brush cytology were 0.923, 0.517, 0.462, and 0.938. The concordance of all methods was 30% for benign and 61% for malignant lesions. Adjuncts identified 92% of carcinoma-in-situ and squamous cell carcinoma as confirmed by histopathology, in contrast to clinical findings alone in which 62% of these lesions were identified (p=0.046). In conclusion, adjunct diagnostic methods decreased the level of uncertainty for the diagnosis of oral malignancies and lichenoid dysplasias when applied as adjuncts to clinical examination.

How many times can we use a phosphor plate? A preliminary study.

OBJECTIVES: Digital radiography has become a useful tool in daily dental practice due to the advances in imaging technologies. Charge coupled devices (CCDs) and photostimulable phosphor plates (PSPs) are currently in use for dental imaging; however, the longevity of PSPs in dental practice is not yet established. The aim of this study was to determine the service life of PSPs in a clinical setting. METHODS: Five unused PSPs were exposed with a conventional X-ray device and converted into digital images with Digora Optime (Soredex, Milwaukee, WI). These were recorded as the baseline images. Subsequent digital images of the plates were obtained after 20, 40, 60, 80, 100, 120, 140, 160, 180 and 200 exposures. All radiographic images were subtracted from the first digital image (baseline) and the mean grey values (MGVs) of the subtracted images were established using software. The data were grouped in 3 classes according to the number of exposures (20-80; 100-140; 160-200), and were analysed using variance analysis and chi(2) tests. RESULTS: The MGVs of the subtracted images varied between 126.25 and 127.59, and the difference was not significant among the groups (P = 0.11). However, the differences between the MGVs of the plates on each exposure settings were significantly different than those of the baseline image (P < 0.05). CONCLUSIONS: The findings of this study revealed that even though a slight deterioration occurred after the first exposure, each plate can be used up to 200 times. Further studies are required to reach a more concrete conclusion.

Turkish dentists' knowledge of head and neck cancer therapy-related complications: implications for the future.

UNLABELLED: The objective was to determine the level of knowledge about the orodental complications and their prevention/management in head and neck cancer therapy. MATERIALS AND METHODS: A 15-item questionnaire which was obtained from National Institute of Dental and Craniofacial Research that contained information about the orodental complications of the cancer therapy and the dentists' role to provide their treatment protocols. The pollsters visited 380 respondents, and the replies were analysed with stratified and logistic data analyses. Overall correct replies ranged from 14.71% to 99.5%. The participants knew the basic knowledge of the complications of cancer therapy; however, they failed to answer to the questions about the required clinical practices. The gender (P = 0.967), age (P = 0.977) and the duration of practice (P = 0.99) were not significant factors in providing correct replies. The rate of correct replies were not different among the test groups (P = 0.953). As a conclusion, rectification of dental curricula, organization of postgraduation courses, foundation of national councils for stimulation of the healthcare providers to incorporate knowledge into practice, to monitor the continuity of those programmes, and to award the dental practitioners who keep up the recent literature and optimal clinical practice are vital to improve the life quality of cancer patients.

The frequency of periodontal infrabony defects on panoramic radiographs of an adult population seeking dental care.

By means of panoramic radiography (PR), the frequency and location of interproximal infrabony defects (IPIDs), their relationship with age, gender and remaining teeth were studied in 416 individuals seeking dental care. The presence/absence of IPIDs and the defect depths were evaluated on mesial and distal surfaces of a total of 8,964 teeth. One or more infrabony defects were recorded on 23% of the PRs (96 individuals, 152 IPIDs). The frequency of infrabony defects < or = 3 mm, 3-5 mm and > or =5 mm was 12.5%, 9.6% and 3.6% respectively. The number of infrabony defects > or = 5 mm was significantly lower than infrabony defects in < or =3 mm and 3-5 mm groups (p<0.05). The difference between the frequency of IPIDs among two genders was non-significant (20.6% for females, 26.8% for males). The IPIDs were most prevalent in the oldest group (>50 years), which also presented with significantly more missing teeth (p<0.05). The most frequent locations for IPIDs were maxillary and mandibulary molar teeth.

Efficacy of a new software in eliminating the angulation errors in digital subtraction radiography.

OBJECTIVES: To evaluate the efficacy of a new software developed for digital subtraction radiography at tolerating the vertical and horizontal angulation changes between the X-ray source and object. METHODS: The right first molar of a preserved dry mandible was imaged with 0 degrees vertical and 0 degrees horizontal tube angulation. Then, the vertical angle was changed to +10 degrees, -10 degrees, +15 degrees and -15 degrees, and the same tooth was radiographed in each condition, accordingly. The same procedure was performed with 5 degrees horizontal angular modifications in both mesial and distal directions. All radiographs were automatically developed and were digitized with 600 dots per inch (dpi) spatial resolution. New software and Emago were used to subtract the images with angulation alterations from the original image, and a total of 20 subtracted images were obtained. Ten experienced specialists evaluated the images and rated the efficacy of the programs. Data were analysed statistically and alpha was accepted as 0.05. RESULTS: The total score of the new software was 190 and that of Emago was 117 for vertical angular alterations, whereas the scores were 51 and 21, respectively, for horizontal angular alterations. The differences between the overall scores of the softwares were statistically significant (P<0.05). Overall evaluation revealed that the new software was rated with higher scores for subtracted images obtained with both vertical and horizontal angular alterations. CONCLUSIONS: Both programs managed to tolerate vertical angulation alterations up to 10 degrees and horizontal angulation changes up to 5 degrees ; however, the new program performed better than Emago.

The statistical investigation on airborne fungi and pollen grains of atmosphere in Izmir-Turkey.

This study aims to investigate the differences in the concentrations of airborne fungi and pollens between the towns located in the province of Izmir and to determine the factors contributing to these differences. Five stations in each of four towns (Buca, Konak, Bornova, and Karsiyaka) were randomly selected as the research areas. Fungus (cfu/m(3)) and pollen counts (cm(2)/pollen count) in the air samples collected from each station between June 2003 and May 2004 were measured. The results revealed that whereas Karsiyaka had the highest fungus concentration (521.33 +/- 777.1), Buca and Bornova had the lowest concentration (482.67 +/- 308.44). The mean fungus concentration in the province of Izmir was 501.5 +/- 486.7. Pollen concentration was the highest in Konak (486.67 +/- 839.06) and the lowest in Bornova (369.83 +/- 551.13). Fungus and pollen concentrations revealed no difference between the towns (p > 0.05). The relationship between pollen-fungus concentrations and temperature-dust-humidity-sulphur-dioxide was investigated but it was found statistically insignificant (p > 0.05). As a result of regression analysis, it was determined that correlation of atmospheric parameters had no effects on pollen and fungus concentrations (p > 0.05).

Clinical efficacy of a new software developed for dental digital subtraction radiography.

OBJECTIVES: The aim of this study was to test and compare the efficacy of software developed recently for digital subtraction radiography (DSR) in vivo. METHODS: An algorithm performing both manual and automated image reconstructions and contrast correction was developed for the manipulation of radiographic images. Pre- and post-operative radiographic images of ten patients were obtained and the automated subtraction analyses were performed using four different softwares (new software, Emago, Photoshop 8.0 and Paintshop Pro 9). Ten experienced dental specialists evaluated the clinical efficacy of each program and scored the softwares by using visual analogue scales (VAS). The results were statistically analysed and alpha was set as 0.05. RESULTS: The newly developed algorithm received higher scores than the others (new software =67.89, Emago = 64.26, Paintshop Pro 9 = 33.41 and Photoshop 8.0 = 27.24, respectively). The clinical efficacies of the new software and Emago were not significantly different (P = 0.720); likewise, Photoshop 8.0 and Paintshop Pro 9 performed comparably (P = 0.295). CONCLUSIONS: Considering this study, the new software and Emago would be suggested for DSR in dental practice.

The effects of incremental brightness and contrast adjustments on radiographic data: a quantitative study.

OBJECTIVES: To determine the border level of brightness and contrast changes in order to prevent the loss of originality of the quantitative data on digital dental radiographs. METHODS: After measuring the baseline mean grey values (MGVs) of a fixed region of interest on the alveolar bone and an aluminium step wedge, incremental brightness and contrast adjustments were performed on a digital periapical radiograph. The distribution of the data was analysed to investigate the significance of the changes on radiodensitometric data after incremental increase of brightness and contrast. RESULTS: The original MGVs were easily retrieved after brightness adjustments; however, the contrast increase led to more complicated density changes. The originality of the data was saved up to 50 units of contrast increase, but further than this limit, significant radiodensitometric changes occurred. CONCLUSIONS: Contrast adjustments should be performed cautiously when making quantitative analyses on the digital radiographs.