Showing papers in "European Journal of Dentistry in 2007"

Effect of Mouthrinse Containing Propolis on Oral Microorganisms and Human Gingival Fibroblasts

Abstract: Objectives The aim of this study was to compare the effects of four different mouthrinse containing propolis solutions and mouthrinse containing 0.2% chlorhexidine (CHX) on oral microorganisms and human gingival fibroblasts.

Hypodontia. Does the Prevalence and Distribution Pattern Differ in Orthodontic Patients

Abstract: Objective The aim of this study was to document the prevalence of hypodontia in the permanent dentition among a group of Turkish sample who sought orthodontic treatment and to compare present results with the specific findings of other populations. The occurrence was evaluated in relation to gender, specific missing teeth, the location and pattern of distribution in the maxillary and mandibular arches and right and left sides.

Platelet rich plasma: myth or reality?

Abstract: Platelet rich plasma (PRP), also termed autologous platelet gel, plasma rich in growth factors (PRGF), platelet concentrate (PC), is essentially an increased concentration of autologous platelets suspended in a small amount of plasma after centrifugation. Basically, patient’s blood is collected and centrifuged at varying speeds until it separates into 3 layers: platelet poor plasma (PPP), PRP, and red blood cells. Usually 2 spins are used. The first spin (“Hard spin”) separates the platelet poor plasma (PPP) from the red fraction and platelet rich plasma (PRP). The second spin (“Soft spin”) separates the red fraction from the PRP. The material with the highest specific gravity (PRP) will be deposited at the bottom of the tube. Immediately prior to application, a platelet activator/agonist (topical bovine thrombin and 10% calcium chloride) is added to activate the clotting cascade, producing a platelet gel. The whole process takes approximately 12 minutes and produces a platelet concentration of 3-5x that of native plasma.1,2 Platelets play a fundamental role in hemostasis and are a natural source of growth factors. Growth factors, stored within platelet α-granules, include platelet derived growth factor (PDGF), insulin like growth factor (IGF), vascular endothelial growth factor (VEGF), platelet derived angiogenic factor (PDAF), and transforming growth factor beta (TGF-β). The release of these growth factors is triggered by the activation of platelets that can be initiated by a variety of substances or stimuli such as thrombin, calcium chloride, or collagen. Growth factors are involved in key stages of wound healing and regenerative processes including chemotaxis, proliferation, differentiation, and angiogenesis.3 According to the definition of PRP, it may be assumed that these growth factors are present at increased concentrations in PRP. In addition to growth factors (GFs), platelets release numerous other substances (e.g., fibronectin, vitronectin, sphingosine 1-phosphate, etc...) that are important in wound healing. An advantage of PRP over the use of single recombinant human growth factor delivery is the release of multiple growth factors and differentiation factors upon platelet activation.4 Recently, the morphologic and molecular configuration of PRP was reported, it showed PRP is a fibrin framework over platelets that has the potential to support regenerative matrix.5,6 The rationale for using PRP in soft and hard augmentation are to accelerate vascularization of the graft, improve soft tissue healing, reduce post operative morbidity, and enhance bone regeneration.7 Advantages of using an autologous PRP include no risk of cross reactivity, immune reaction or disease transmission.8 In addition, the use of PRP improves handling of particulate graft materials and easier packing into a grafting site, thus facilitating space maintenance and potential bone regeneration.9,10 Since PRP contains several GFs (e.g., PDGF, VEGF, etc...) that are capable to stimulate angiogenesis and increase fibroblast cell differentiation, using PRP to promote soft tissue healing has been proposed.2 Research showed that PRP and analogous products improve graft adhesion and minimizes micro-movement, providing the most advantageous environment for graft acceptance.11,12 It has been also proposed that PRP accelerates wound maturity and epithelialization, hence decreased scar formation. PDGF and epidermal growth factor (EGF) are the main growth factors involved in fibroblast migration, proliferation, and collagen synthesis. Increased concentrations of these growth factors are likely the reason for the accelerated soft tissue wound healing, which is suggested to be at least 2-3 times faster than that of normal.13 For the hard tissue, growth factors released from PRP are likely to effect local vital cells such as osteoblasts. The addition of PRP to stromal cells has demonstrated angiogenic and osteogenic properties in animal models.14 The use of PRP to enhance bone regeneration has been documented in periodontal defects,15-17 extraction sockets,18 during implant placement,19,20 and in guided bone regeneration procedures around implants, including sinus augmentation.21 One of the major drawbacks of bone augmentation is the extended healing time required. Hence, one of the major reasons proposed for the use of PRP is a reduced healing time. A shortened graft healing time (50%) has been demonstrated in sinus augmentation.22 Accelerated bone regeneration has also been demonstrated in periodontal defects distal to second molars when PRP is added at the time of extraction of impacted third molars.18 Unfortunately these results cannot be used to expound the beneficial effects of PRP, as biopsies were not taken from any of the control sites. In animal studies, when cancellous bone from the iliac crest was used as graft material for sinus lifts with or without PRP, biopsies showed both PRP and control groups achieved similar results with no statistically significant difference between the two.9,23 It is also true when DFDBA was used as a graft material, PRP did not enhance its ability to form bone.24 Similar findings were also reported when PRP was added to the xenograft (e.g., Bovine HA).25 These results are consistent with those above that failed to demonstrate enhanced bone regeneration when PRP is combined with non-living graft materials. In humans, early controlled studies demonstrated Hom-Lay Wang & Gustavo Avila University of Michigan, USA

Prevalence of Malocclusion AmongAdolescents In Central Anatolia

Abstract: Objectives: The objective of this study was to describe the prevalence of malocclusion in a population of Central Anatolian adolescents in relation to gender. Methods: The sample comprised 2329 teenagers (1125 boys and 1204 girls), aged between 12 and 17 years (mean age: 14.6 yrs). Occlusal anteroposterior relationships were assessed using the Angle classification. Other variables examined were overjet, overbite, crowding, midline diastema, posterior crossbite, and scissors bite. Results:The results showed that about 10.1% of the subjects had normal occlusions, 34.9% of the subjects had Class I malocclusions, 40.0% had Class II Division 1 malocclusions, 4.7% had Class II Division 2 malocclusions and 10.3% had Class III malocclusions. Over 53.5% had normal overbites, and 18.3%, 14.4%, 5.6%, and 8.2% had increased, reduced, edge-to-edge or anterior open bite values, respectively. Overjet relationship was normal in 58.9%, increased in 25.1%, reversed in 10.4%, and edge-to-edge in 5.6%. A posterior crossbite registered in 9.5% and scissors bite in 0.3%. Anterior crowding was present in 65.2% of the sample and midline diastema in 7.0%. No clear gender differences were noted, except for normal overbite (most frequent in girls, P>.001) and increased overbite (most frequent in boys, P>.05) Conclusions: Class II Division 1 malocclusion is the most prevalent occlusal pattern among the Central Anatolian adolescents and the high values (25.1% and 18.3%) of increased overjet and overbite were a reflection of the high prevalence of Class II malocclusion. (Eur J Dent 2007;1:125-131)

Prevalence of malocclusion among adolescents in central anatolia.

Abstract: Objectives The objective of this study was to describe the prevalence of malocclusion in a population of Central Anatolian adolescents in relation to gender.

Evaluation of the erosive potential of soft drinks.

Abstract: Objectives This in vitro study evaluated the capability of different soft drinks (Coca-Cola®-C, Coca-Cola Light®-CL, Guarana®-G, Pepsi Twist®-P and Sprite Light®-SL) to erode dental enamel, relating the percentage of superficial microhardness change (%SMHC) to concentrations of fluoride and phosphate, buffering capacity and pH of these drinks.

Knowledge of and Attitudes towards Preventive Dental Care among Iranian Dentists

Abstract: Objectives: To assess Iranian dentists’ knowledge of and attitudes towards preventive dental care Methods: A questionnaire survey was conducted at two nationwide annual dental congresses in 2004 and 2005 in Tehran, Iran. Dentists’ level of knowledge was assessed based on their responses on a Likert scale (0-4) to nine statements on preventive dental care. Higher scores indicated more accurate knowledge. Dentists’ attitudes towards preventive dental care were rated based on responses on a Likert scale (1-7) to nine pairs of bipolar adjectives. The respondents were to choose the response which best described their opinion. Higher scores indicated more positive attitudes. Of 1033 responding dentists, 980 (64% men) were deemed eligible for this study. Statistical evaluation was by t-test and the Chi-square test Results: Highest ratings were obtained for knowledge of the role of sugar consumption (Mean±SD: 3.73±0.60), sealants (3.58±0.68), and water fluoridation (3.35±0.81) in caries prevention; the lowest for their knowledge of the superiority of the use of fluoride toothpaste over technique of brushing (1.11±1.09). Dentists’ attitudes towards preventive dental care appeared most positive regarding its usefulness (Useful — Useless; 6.67±0.94), value (Valuable — Worthless; 6.59±0.98) to the community and for its status as a scientific (Scientific — Unscientific; 6.47±1.06) subject. Overall, female dentists had more favourable attitudes towards preventive dental care than male colleagues Conclusions: Preventive dentistry should be emphasised in dental education in order to update dentists’ knowledge and attitudes regarding preventive dental care. (Eur J Dent 2007;1:222-229)

Influence of Diamond Sono-Abrasion, Air-Abrasion and Er:YAG Laser Irradiation on Bonding of Different Adhesive Systems to Dentin.

Abstract: Objectives Different surface treatments may affect bonding performance of adhesive systems to dentin. This study evaluated the influence of different methods of surface treatment on adhesion of bonding agents to dentin.

The use of double-needle canula method for temporomandibular joint arthrocentesis: clinical report.

Abstract: Objective The purpose of this study is to demonstrate a temporomandibular lavage instrument with double needles in a single canula that make the procedure easier for surgeons. Materials and methods 38 year old woman was referred to our department with pain on the right temporomandibular joint (TMJ) region and restricted mouth opening. Magnetic resonance imaging reveals anterior disc displacement without reduction of the right TMJ. TMJ lysis and lavage was performed with double needle canula method. Results The upper joint space was successfully lavaged with 50 mL of 0.9% saline solution. Maximal mouth opening and lateral jaw movement increased and jaw functions improved immediately after the procedure. Conclusion It is recommended as a simple alternative to classical arthrocentesis with two needles that it is easy to use and enables to perform lysis and lavage with a single puncture.

Gingival Hyperplasia as an Early Diagnostic Oral Manifestation in Acute Monocytic Leukemia: A Case Report

Abstract: Acute Myeloblastic Leukemia (AML) is a malignant disease of bone marrow. Due to its high morbidity rate, early diagnosis and appropriate medical therapy is essential. Rapidly forming gingival hyperplasia is usually the first sign of this disease. This case report describes a 17-year-old female who presented rapid gingival overgrowth together with gingival bleeding in only two weeks time. A medical consultation was asked from hematology clinics and after a detailed medical examination Acute Monocytic Leukemia (FAB M5) was rendered. Chemotherapy was the choice of treatment. The patient responded well to chemotherapeutic induction regimen and after two months of medical therapy disease remised and gingival hyperplasia regressed. This case report shows that the gingival hyperplasia may represent an initial manifestation of an underlying systemic disease. Also, early medical therapy in acute monocytic leukemia may resolve the gingival hyperplasia that companies the disease progression.

Evaluation of cariogenic bacteria.

Abstract: Objectives : The evaluation of Mutans streptococci (MS) is one of the index for caries risk. Dentocult TM and CRT TM are commercial kits to detect and evaluate MS, conveniently. However, the evaluation of MS has also been carried out simply using an instruction manual. But the instruction manual is not easy to use for evaluation of MS. The aim of this study was to examine the utility of modified Mitis-Salivalius Bacitracin (MSB) agar medium compared with MSB agar medium and commercial kits, and to establish a convenient kit (mMSB-kit) using modified MSB agar. Methods : The MS in stimulated saliva from 27 subjects were detected by MSB, modified MSB agar medium and commercial kits. Laboratory and clinically isolated strains of MS were similarly evaluated. The ratios of MS in detected bacteria were compared by ELISA. Results : The scores using an mMSB-kit on the basis of modified MSB agar medium were tabulated. Saliva samples showed different levels of MS between culture methods and the commercial kit. Some samples which were full of MS were not detected by the commercial kit. The detection of MS by modified MSB agar medium and mMSB-kit were significantly higher when compared with MSB agar medium, CRT TM , (P< .01) and Dentocult SM TM (P<.05). Conclusion : The sensitivity for detection of MS is higher for modified MSB agar medium when compared with MSB agar medium. The mMSB-kit can be used simply, and can be an important contributor for the evaluation of MS as a caries risk factor. (Eur J Dent 2007;1:31-39)

Detection of Enterococcus faecalis in Necrotic Teeth Root Canals by Culture and Polymerase Chain Reaction Methods.

Abstract: Objectives The aim of this study was to investigate the presence of Enterococcus faecalis in endodontic infections in both deciduous and permanent teeth by culture and polymerase chain reaction (PCR) methods. Methods A total of 145 children aged 5-13 years old were involved in this study. The presence of E. faecalis in necrotic deciduous and permanent teeth root canals was studied using culture and polymerase chain reaction methods. Results Among 145 molar teeth, 57% (n=83) presented necrotic asymptomatic pulp tissues and were included in this study. Culture and PCR methods detected the test species in 18 and 22 of 83 teeth involved, respectively. E. faecalis was cultured from 8 (18%) of 45 necrotic deciduous teeth and from 10 (26%) of 38 necrotic permanent teeth. PCR detection identified the target species in 10 (22%) and 12 (32%) of necrotic deciduous and permanent teeth respectively. Statistically significant difference in the presence of E. faecalis in deciduous and permanent teeth was found by culture and PCR methods (P=0.03 and 0.02, respectively). The difference in the presence of E. faecalis between two different methods was not statistically significant (P>.05). Conclusions The results of the present study confirm that both culture and PCR methods are sensitive to detect E. faecalis in root canals.

Color stability of silicone or acrylic denture liners: an in vitro investigation.

Abstract: Objectives The aim of this study was to compare the color stability of three acrylic based hard liners (Ufi gel hard, Dura-Liner II, Tokuso Rebase) and two silicone based soft liners (Ufi gel permanent, Molloplast B) by using the colorimeter.

The Prevalence of Carotid Artery Calcification on the Panoramic Radiographs in Cappadocia RegionPopulation

Abstract: Objectives The aim of this study is to determine retrospectively the presence of carotid artery calcifications (CACs) detected on panoramic radiographs (PRs) in a group of Turkish population. Further, the relationships between CACs and gender, life style, and medical history were evaluated.

Stress analysis of a maxillary central incisor restored with different posts.

Abstract: Objectives: To evaluate the effects of different post materials on the stress distribution in an endodontically treated maxillary incisor. Materials and Methods: A pseudo 3-dimensional finite element model was created in a labiolingual cross-sectional view of a maxillary central incisor and modified according to five posts with different physical properties consisting stainless steel, titanium, gold alloy, glass fiber (Snowpost), and carbon fiber (Composipost). A 200 N force was then applied from two different directions; a) vertical load on the incisal edge, b) 45 degree diagonal load above the cingulum location. Stress distribution and values were then calculated by considering the pseudo three dimensional von Mises stress criteria. Results: Under two loading conditions, post made of steel showed greatest stress concentration at the post/dentin interface followed by titanium, gold alloy, Snowpost and Composipost. However, Composipost, which elastic modulus was closer to the dentin, produced highest stress values at 1/3 cervical area. Conclusions: Within the limitation of this simulated mechanical analysis, we can conclude that the physical characteristics of posts were important on stress distributions in post and core applications. Glass fiber post revealed more balanced stress distribution under functional forces. (Eur J Dent 2007;2:67-71)

Fluoride levels of human plasma and breast milk.

Abstract: Objectives The aim of this study was to determine the fluoride levels in breast milk and plasma of lactating mothers who regularly consumed drinking water with low levels of fluoride. Methods One hundred twenty five healthy mothers aged between 20-30 years old who had given birth within 5-7 days were included in the study. Besides being otherwise healthy, the primary selection criteria stipulated the absence of fluoride supplement consumption one month before delivery. Approximately 5 ml breast milk and 5 ml blood samples were obtained from each participating mother at a hospital setting, where the mothers were scheduled for a regular hospital diet. The blood samples were centrifuged in fluoride-free heparinized polyethylene tubes and stored at -18 degrees C until measurements were made. Breast milk samples were directly refrigerated as with blood samples until measurements. The fluoride concentrations of milk and blood samples were assessed using an ion-selective fluoride electrode combined with an ion analyzer. Results The fluoride levels of the plasma and breast milk samples were measured as 0.017+/-0.011 ppm and 0.006+/-0.002 ppm, respectively. The fluoride concentration of plasma was significantly higher than that of breast milk (P Conclusion A limited level of fluoride transmission from plasma to breast milk was detected. Nevertheless, a significant correlation between the fluoride concentrations of breast milk and plasma was evident.

An unusual association of odontomas with primary teeth.

Abstract: Odontomas generally appear as small, solitary or multiple radio-opaque lesions found on routine radiographic examinations. Traditionally, odontomas have been classified as benign odontogenic tumors and are subdivided into complex or compound odontomas morphologically. Compound odontomas commonly occur in the incisor-canine region of the maxilla and complex odontomas are frequently located in the premolar and molar region of both jaws. Occasionally, odontoma may cause disturbances in the eruption of teeth such as impaction, delay eruption or retention of primary teeth. In general, odontomas occur more often in the permanent dentition and are very rarely associated with the primary teeth. In this report; two cases of compound odontoma associated with primary teeth is presented. (Eur J Dent 2007;1:45-49).

The Effect of ABO Blood Types on Periodontal Status.

Abstract: Objectives The purpose of the present study was to determine whether there was a relationship between periodontal diseases and ABO blood groups. Methods This epidemiological study was carried out on 1351 subjects who were randomly selected from individuals referred to the Faculty of Dentistry clinics for periodontal treatment or for other reasons regarding dental health. The study based on periodontal condition, blood group, and medical history. The subjects were divided into three groups as those with gingivitis, periodontitis, and the healthy ones. The effects of blood subgroups on periodontal health, gingivitis and periodontitis were investigated separately. Results A relatively higher percentage of A group patients was found in gingivitis group and relatively higher percentage of O group patients was found in periodontitis group. A significant relationship was also determined between Rh factor and gingivitis. Conclusions ABO blood subgroups and Rh factor may constitute a risk factor on the development of periodontal disease. However, long-term studies are needed to make a more comprehensive assessment of the effects of ABO group on periodontal diseases.

Esthetic rehabilitation of bilateral geminated teeth: a case report.

Abstract: Geminated teeth are the consequences of developmental anomalies leading to the eruption of joined elements. According to current definitions, gemination occurs when one tooth bud tries to divide, while fusion occurs if two buds unite. Clinical experience shows, however that diagnosis can be complicated due to superimposed anomalies. This report describes a unique case of bilateral gemination of permanent maxillary central incisors. The esthetic rehabilitation of the geminated incisors accomplished utilizing all ceramic crowns. It is important that in these types of cases, reaching to the available esthetics and avoiding the complication of caries and periodontal problems with prosthetic application is satisfactory.

Apical leakage of different gutta-percha techniques: thermafil, js quick-fill, soft core, microseal, system B and lateral condensation with a computerized fluid filtration meter.

Abstract: Objectives To investigate apical leakage of roots filled with 6 different gutta-percha techniques; Thermafil, JS Quick-Fill, Soft Core, Microseal, System B and lateral condensation using a new computerized filtration meter. Materials and methods 60 extracted single rooted teeth were used. Coronal part of each tooth was removed and the root canals were prepared with step-back technique. The roots were randomly divided into six groups of 10 teeth, filled by one of the obturation technique and Kerr sealer. The teeth were kept in 100% humidity for 2 years. After this period, apical parts of roots (10 +/- 0.05 mm) were attached to computerized fluid filtration meter. Apical leakage quantity was determined as mul.cmH(2)O(-1).min(-1). Results Statistical analysis indicated that Thermafil, Soft Core, Quick-Fill and System B techniques showed lower leakage than Microseal and lateral condensation (P .05). Conclusions Thermafil, Soft Core, Quick-Fill and System B techniques showed lower leakage than Microseal and lateral condensation. In addition, this new computerized fluid filtration meter allowed quantitative measurement of leakage easily.

Effects of fluorosis and bleaching on shear bond strengths of orthodontic brackets.

Abstract: Objectives: To evaluate the effects of fluorosis and bleaching on shear bond strengths of orthodontic brackets. Methods: A total of 45 (30 fluorosed and 15 non-fluorosed) non-carious freshly extracted human permanent premolar teeth which were extracted for orthodontic reasons and without any caries or visible defects were used in this study. Fluorosed teeth were selected according to the modified Thylstrup and Fejerskov index (TFI), which is based on the clinical changes in fluorosed teeth. First group consisted of 15 fluorosed teeth. Second group of fluorosed teeth were bleached with a 35% hydrogen peroxide office bleaching agent. Third group served as control. No bleaching procedure was applied. Orthodontic brackets were bonded with a light cure composite resin and cured with a halogen light. After bonding, shear bond strengths of the brackets were tested with Universal testing machine. Results: The results showed that fluorosis only and bleaching of fluorosed teeth significantly reduced the bond strengths of the orthodontic brackets (P>.001). Although bleaching of fluorosed teeth decreased the values more, no statistically significant difference was found between fluorosis group and fluorosis+bleaching group (P Conclusions: Fluorosis and bleaching of fluorosed teeth reduce bracket bond strength to enamel, but the bond strength with these still exceed the minimum 6 to 8 MPa required to expect adequate clinical performance. (Eur J Dent 2007;1:230-235)

Reattachment of coronal fragment using fiber-reinforced post: a case report.

Abstract: Coronal fractures of permanent dentition are the most frequent type of dental injury. If the original tooth fragment is retained following fracture, the natural tooth structures can be reattached using adhesive protocols. The development and use of fiber-reinforced composite root canal posts make possible of the reattachment of the crown esthetically. This case report presents a clinical technique to reattachment maxillary lateral incisor tooth after trauma using direct fiber-reinforced post systems. At the 1-year follow-up, a slightly marginal discoloration, but no recurrent decay or composite clefts were detected and the resultant appearance was acceptable to the patient.

Hypodontia. Does the Prevalence andDistribution Pattern Differ in OrthodonticPatients

Abstract: Objective: The aim of this study was to document the prevalence of hypodontia in the permanent dentition among a group of Turkish sample who sought orthodontic treatment and to compare present results with the specific findings of other populations. The occurrence was evaluated in relation to gender, specific missing teeth, the location and pattern of distribution in the maxillary and mandibular arches and right and left sides. Materials And Methods: Orthodontic files of 2413 patients (1557 females-mean age: 17.78±5.41 years old and 856 males-mean age:17.02±5.47 years old) which included orthopantomograms, study models, and anamnestic data were examined for evidence of hypodontia. Results: The prevalence of hypodontia was 7.54% (8.09% for female and 6.54% for male). Hypodontia was found considerably more frequently in the maxilla than in the mandible. Similarity in the distribution of missing teeth between the right and left sides was detected. The most frequently missing teeth were the maxillary lateral incisors, followed by the mandibular and maxillary second premolars. The majority of patients had one or two teeth missing, but seldom three or more. Conclusions: Present data for hypodontia were within the wide range reported in the literature. The findings of patients with hypodontia involving the anterior teeth and others missing more than two teeth in the same quadrant were an indication of a great need for orthodontic treatment. By early detection of missing teeth, alternative treatment modalities can be planned and performed with a multidisciplinary team approach. (Eur J Dent 2007;1:167-173)

Cytotoxicity of mouthrinses on epithelial cells by micronucleus test.

Abstract: OBJECTIVES To determine the cytotoxicity of three commercial mouthrinses Klorhex, Andorex and Tanflex on buccal epithelial cells using micronucleus (MN) test. MATERIALS AND METHODS 28 patients with aged 16-24 undergone three mouthrinses' application were analyzed before and after one week exposure. Physiologic saline was used for the control group. The MN incidence was scored in the buccal epithelial of each participants. The difference in pre- and post-treatment after one week incidence of MN and plaque (PI) and gingival indices (GI) was compared by non-parametric statistical tests. RESULTS The micronuclei incidence increased in Klorhex, Tanflex and Andorex groups after exposure to mouth rinses (P .05). In the other study groups, MN incidence was significantly increased after 7 days treatment (P<.05). GI scores of all groups were decreased significantly (P<.05). PI scores were decreased only in the Klorhex group (P<.05). CONCLUSIONS Our primary findings support the presence of possible cytotoxic effects of the mouthrinses on gingival epithelial cells.

Changeability of oral cavity environment.

Abstract: Objectives In dentistry, the results of in vivo studies on drugs, dental fillings or prostheses are routinely evaluated based on selected oral cavity environment parameters at specific time points. Such evaluation may be confounded by ongoing changes in the oral cavity environment induced by diet, drug use, stress and other factors. The study aimed to confirm oral cavity environment changeability.

Gingival Changes in Wistar Rats after Oral Treatment with 4-Nitroquinoline 1-Oxide

Abstract: Objectives:4-nitroquinoline 1-oxide (4NQO)-induced rat tongue carcinogenesis is a useful model for studying oral squamous cell carcinoma. However, gingival changes following 4NQO administration via drinking water are absent in the literature. The aim of this study was to investigate gingival changes concomitant to tongue carcinogenesis induced by 4NQO by means of morphological analysis. Methods:Male Wistar rats were distributed into 3 groups of 10 animals each and treated with 50 ppm 4NQO solution by drinking water for 4, 12 or 20 weeks. Thirty animals were used as negative control. Results: Regarding tongue mucosa, the primary histopathological change i.e., hyperplasia and dysplasia was evidenced after 12 weeks treatment with 4NQO. At 20 weeks, squamous cell carcinoma was found in the majority of animals. Gingival squamous hyperplasia was induced by 4NQO after 20-weeks of treatment. Dysplastic changes appeared in some animals (two cases) as well. Conclusions:Taken together, our results support the notion that 4NQO is more effective in rat tongue mucosa than gingival tissue. Probably, this discrepancy depends strongly on route of administration and the susceptibility with respect to animals species. Certainly, such data will contribute when using this experimental test-system for understanding oral cancer pathogenesis. (Eur J Dent 2007;1:152-157)

Socio-demographic and economic factors affecting the acceptance of removable dentures.

Abstract: Objectives The aim of this study was to evaluate relationships between the socio-demographic and economic factors of patients and the reasons of admission, usage periods of the two types of clinics, frequencies of denture changes, satisfaction levels and preferences of prosthetic dental treatment.

Value of Computed Tomography (CT) in Imaging the Morbidity of Submerged Molars: A Case Report.

Abstract: Submerged primary molars can be difficult to manage due to the developing dentition Rarely in some severe cases, may the surgical interventions be required while ensuring the vital structures are protected Therefore these cases require sophisticated imaging techniques in order to locate the vital structures In this case report, a 17 year old girl who had a retained and submerged deciduous molar which caused impaction of the second premolar and tipping of the first molar was presented In addition, value of computed tomography (CT) for locating the vital anatomic structures was discussed In our case, CT has been supplied effective information about localization of the vital structures and amount of bone volume during the diagnosis and treatment planning period in addition to the routine dental radiographies

Mandibular incisor extraction treatment of a class I malocclusion with bolton discrepancy: a case report.

Abstract: Many approaches for crowded mandibular anterior teeth are currently employed: distal movement of posterior teeth, lateral movement of canines, labial movement of incisors, interproximal enamel reduction, removal of premolars, removal of one or two incisors, and various combinations of the above. Selecting the best treatment is often difficult, and all guidelines do not apply to every case. Treatment by extraction of one single mandibular incisor is not popular in the orthodontic profession despite the apparent advantages of the extraction in the region of crowding. A case report is presented one mandibular incisor extraction treatment of a 16 year-old female with a Class I malocclusion that shows a significant mandibular arch length deficiency and mandibular tooth-size excess. In this case, the degree of mandibular anterior dental crowding, existing mandibular tooth-size excess, and the dental midline discrepancy were indicated the extraction of one mandibular incisor.

Use of FT-Raman Spectroscopy to Determine the Degree of Polymerization of Dental Composite Resin Cured with a New Light Source.

Abstract: OBJECTIVES To use the FT-Raman spectroscopy for evaluation the degree of polymerization of dental composite as a result of photo curing with a new light source in comparison to the conventional halogen light. MATERIALS AND METHODS In this study a new light source, based on a metal-halide lamp (TOPSPOT G12) was developed at NRC-Egypt for curing dental composites. Two groups of 108 composite samples each were cured using both the new light source and a conventional halogen source, as a control source. Different samples' sizes (2x2, 3x3 and 6x3 mm(2)) were cured for different periods of time (2, 4, 8, 12, 20, and 40 seconds). The spectroscopic data were analyzed statistically by ANOVA and Duncan's multiple range test (P< .05). RESULTS The results showed that the samples cured by the new metal-halide source produced higher polymerization rates than those cured by the halogen source. The polymerization rate was directly proportional to the exposure time and inversely proportional to the sample size, irrespective to the light source used. The results also showed that 12 seconds of metal-halide light curing produced polymerization rate comparable to or even higher than that produced by 40 seconds halogen light curing. CONCLUSIONS The new light source produced a satisfactory degree of polymerization in a remarkable shorter curing time and it can be recommended for clinical use.