Izzet Yavuz

Measuring Bone Density in Healing Periapical Lesions by Using Cone Beam Computed Tomography: A Clinical Investigation

INTRODUCTION Differences in bone density before and after endodontic treatment were examined in teeth with periapical lesions in Hounsfield units (HUs) by using cone beam computed tomography (CBCT). METHODS Sixteen patients requiring endodontic treatment for periapical lesions underwent CBCT scan before and after treatment. Their bone densities were calculated in HUs. The study included 16 lesions measuring 8-10 mm in diameter. HU measurements were taken from an area of 2.25 mm(2) on the CBCT images where the bone density was lowest, before and after treatment. RESULTS The initial and final measurements were compared statistically by using paired samples statistics at the 5% significance level. CONCLUSIONS The results of this study support the use of CBCT to measure bone density before and after endodontic treatment.

NEW METHOD FOR MEASUREMENT OF SURFACE AREAS OF MICROLEAKAGE AT THE PRIMARY TEETH BY BIOMOLECULE CHARACTERISTICS OF METHILENE BLUE

ABSTRACT This study was planned to investigate the feasibility of a different approach as an alternative to the methods for determining the microleakages caused by the dental restorations. Several different methods are currently being implemented to determine the microleakage. Our method, utilizes the molecular characteristics of the methylene blue in which pH adjusted to 6.98, and the surface area covered by the methylene blue dye adsorbed in the areas where leakages have occured subsequent to the thermal conversion similar to the traditional methods. Within the framework of this study, 20 primary molars were divided into two groups, and restorations were made in one group with the glass ionomer cement plus amalgam while the other group of teeth was treated with glass ionomer cement and composite. These two groups were evaluated for surface area measurements using the Mann-Whitney U test with SPSS 10.0 statistical package, and were found to be statisticaly different (p<0.001). It is therefore concluded that this method may be used as a new technique for the determination of microleakage and that it may even be further developed.

Ear nose throat manifestations in hypoidrotic ectodermal dysplasia

The ectodermal dysplasias (EDs) are a large and complex group of inherited disorders. In various combinations, they all share anomalies in ectodermal derived structures: hair, teeth, nails and sweat gland function. Clinical overlap is present among EDs. Few causative genes have been identified, to date. Altered gene expression is not limited to the ectoderm but a concomitant effect on developing mesenchymal structures, with modification of ectodermal-mesenchymal signaling, takes place. The two major categories of ED include the hidrotic and hypohidrotic form, the latter more frequent; they differentiate each other for the presence or absence of sweat glands. We report Ear Nose Throat manifestations of ED, linked to the reduction of mucous glands in the nasal fossae with reduced ciliar function, and decrease salivary glands function. Often patients report an increased rate of infections of the upper respiratory tract and of the ear. Nasal obstruction due to the presence of nasal crusting, hearing loss and throat hoarseness are the most represented symptoms. Environmental measures, including a correct air temperature and humidification, is mandatory above all in subjects affected by hypohidrotic form.

Evaluation of ectodermal dysplasia.

This case series report outlines possible cranio‐maxillofacial deformation consequences associated with ectodermal dysplasia (ED) and embryonic malformations, including dental agenesis. Also described are the oral aspects and rehabilitation. A total of 14 ED patients (7 males and 7 females, aged 5‐45 years) underwent clinical examination before assessment and treatment. Lateral cephalometric radiography, Steiners analysis, and respiratory capacity tests were performed. Most of the patients had sparse or absent hair, a short face with an unusual facial concavity, a maxillary retrusion, and a relative mandible protrusion. Depending on age and orthopedic abnormalities, patients were treated with prosthodontic and orthodontic approaches or implant treatment. Therapists should take a comprehensive and multidisciplinary approach with these patients to improve their dental, masticatory, growth, and orthognathic conditions, as well as esthetic appearance.

A new biological approach to guided bone and tissue regeneration.

The purpose of this study was to determine the potential of platelet-rich fibrin (PRF) membranes used for guided bone and tissue regeneration. A patient with insufficient alveolar ridge width in aesthetic zone was enrolled. The patients blood was centrifuged to obtain PRF membranes. Autogenous bone graft was mixed with bovine hydroxyapatite, PRF particles and applied to fill the defect. Five PRF membranes were placed over the bone mix. After 4 months a cone-beam CT was performed to evaluate bone regeneration. The use of PRF as cover membrane permitted a rapid epithelisation and represented an effective barrier versus epithelial cell penetration. After 4 months the site appeared precociously healed and the bone volume increased. This new approach represents a predictable method of augmenting deficient alveolar ridges. Guided bone regeneration with PRF showed limitation compared with guided bone regeneration using collagen membrane in terms of bone gain. The association of collagen membrane and PRF could be a good association.

A new phenotypic variant in cleidocranial dysplasia (CCD) associated with mutation c.391C>T of the RUNX2 gene

The RUNX2 gene is a physiological regulatory gene implicated in the development of cleidocranial dysplasia (CCD). A 13-month-old child presented with clinical features of CCD. At the age of 3 years the diagnosis was corroborated by clinical genetic assessment and DNA analysis, revealing a missense mutation p.R131C (c.391C>T) in RUNX2. At the age of 8 years the child was found to have a unique dental phenotype, represented by lack of supernumerary teeth and congenital absence of one tooth. A simple therapeutic approach was adopted, consisting of interceptive orthodontic treatment. The presence of this specific missense mutation in RUNX2, associated with the lack of typical supernumerary teeth may suggest a phenotype–genotype association.

A new method: measurement of microleakage volume using human, dog and bovine permanent teeth

This study investigates the feasibility of a different new approach to determining the microleakage volume associated with dental restorations (Class V cavity restorated with glass ionomer cement + high copper amalgam) and the relative marginal adaptation deficiency of dog, bovine and human permanent teeth in in vitro conditions. Also researched is the appropriateness of using dog and bovine teeth in in vitro studies rather than human teeth. Our method utilizes the molecular adsorption characteristics of methylene blue. Within the framework of this study, 60 permanent teeth (20 human, 20 dogs and 20 bovine) were used. These groups were evaluated statistically, of which indicated no statistically significant differences (p > 0.05). It was also concluded that this preliminary investigation showed that the new microleakage volume measurement method may be a valuable new technique for the in vitro study of microleakage dynamics around dental restorations.

Comparative Evaluation of the Effects of Ozone, Diode Laser, and Traditional Cavity Disinfectants on Microleakage

Aim: This study aimed to evaluate the effects on microleakage of the application of ozone gas, laser and traditional cavity disinfection under in vitro conditions. Material and Methods: Ninety third-molar teeth extracted for various reasons were used in this study. All the teeth were prepared with a standard V cavity on the buccal surface. Then the teeth were randomly allocated to one of 6 groups of 15 teeth; Group 1 benzalkonium chloride, Group 2 chlorhexidine gluconate, Group 3 sodium hypochloride, Group 4 diode laser, Group 5 ozone gas, Group 6 control group- no disinfection was applied. Primer was applied to the cavities, then bond and 10-s polymerization. Clearfil AP-X was used in the cavities as a hybrid composite and polymerized for 20 s. The samples then underwent 1000 thermal cycles of 30-s application, in baths at temperatures between 5 ± 2 °C and 55 ± 2 °C. All the samples were stirred in 0.5% basic phuxine solution and the sections taken under stereomicroscope were examined and photographed at 15 × magnification. SEM analysis was made and the obtained results were statistically evaluated with the Kruskal–Wallis test. Results: No significant difference was seen between the groups in respect of the microleakage values of both the occlusal and gingival edges (p < 0.05). Comparison of the microleakage values of the occlusal and gingival edges of the groups determined the least leakage to be in the ozone group (p < 0.05). Conclusion: No statistical significance was determined between the groups. However, the mean least microleakage was found in the ozone group and the highest amount in the control group.

Investigation of Microorganisms in Infected Dental Root Canals

ABSTRACT Objective: The purpose of this study is to investigate the type of microorganisms isolated from necrotic pulp tissues and from failed endodontic treatments in infected root canals. Methods: This study is based on an experiment conducted on 90 patients between November, 2002 and November, 2003 using a sampling. One hundred single root canals were microbiologically sampled from these patients by using sterile paper points. Among 100 canals sampled, 61 had primary infection and 39 had a history of secondary infection. Microorganisms were isolated and identified by using established advanced microbiologic techniques for anaerobic species. Results: A total of 197 cultivable isolates were recovered, the microbial findings in both types of canals, such as the number of species isolated, the 68.0% of Gram-positives and 27.9% gram-negatives, the 52.8% of facultative and 43.1 % strict anaerobic microorganisms 4.1% fungi and so on. Ten canals presented no microbial growth. Conclusions: The prevalence of bacteria and fungi found in 100 root canals is the prevalence of the microbial genera in primary and secondary endodontic infection. Peptostreptococcus spp was the most predominantly isolated microbial genera, followed by Streptococcus spp (14.2%), Porphyromonas spp (12.2%), E. faecalis (9.6%), Staphylococcus salivarius (8.6%), Prevotella spp (8.1%), Lactobacillus spp (7.1%), Actinomyces spp (7.1%), Candida albicans (4.1%), Fusobacterium spp (3.6%) Veillonella spp (2.5%), Eubacterium spp (2.5%), Bacillus spp (2.0%), and Escherichial coli (1.6%) were other types of bacteria recovered.

The Detailed Evaluation of Supernumerary Teeth with the Aid of Cone Beam Computed Tomography

ABSTRACT The aim of this paper is to demonstrate the application of a recently developed three-dimensional imaging system, cone beam computed tomography, in the detailed evaluation of supernumerary teeth. Two-hundred and twenty three patients with supernumerary teeth (68 females and 155 males) were included in this study. Patients ranged in age from 12 to 25 years. Supernumerary teeth were detected by clinical examination and traditional radiographies. Moreover, careful investigation for more details was made with the cone beam computed tomography. Supernumerary teeth which were detected with the examinations of the cone beam computed tomography images were classified according to the number, location, shape and eruption rate. The prevalence of supernumerary teeth was determined to be 1.45% of the study population. Males were affected more than females in a ratio of 2.3:1. Supernumerary teeth were most frequently located in 86.2% of the cases in the maxilla; 10.1% in the mandible and 3.7% both in the maxilla and mandible. Supernumerary teeth were most commonly conical in shape (68.8%). One supernumerary tooth was present in 67.7% of the patients, 30.9% had two, and 1.4% had three supernumeraries. Definite and early diagnosis of the supernumerary teeth is very important. Detailed examinations and evaluations of these teeth with three-dimensional images is very benefical in terms of treatment planning and preventing complications which may occur.