Effect of gender, facial dimensions, body mass index and type of functional occlusion on bite force

OBJECTIVE: Some factors such as gender, age, craniofacial morphology, body structure, occlusal contact patterns may affect the maximum bite force. Thus, the purposes of this study were to determine the mean maximum bite force in individuals with normal occlusion, and to examine the effect of gender, facial dimensions, body mass index (BMI), type of functional occlusion (canine guidance and group function occlusion) and balancing side interferences on it. MATERIAL AND METHODS: Thirty-four individuals aged 19-20 years-old were selected for this study. Maximum bite force was measured with strain-gauge transducers at first molar region. Facial dimensions were defined by standardized frontal photographs as follows: anterior total facial height (ATFH), bizygomathic facial width (BFW) and intergonial width (IGW). BMI was calculated using the equation weight/height². The type of functional occlusion and the balancing side interferences of the subjects were identified by clinical examination. RESULTS: Bite force was found to be significantly higher in men than women (

Kompozit rezin materyallerin farklı ışık kaynaklarıyla polimerizasyonu sırasında oluşan ısısal değişikliklerin incelenmesi

Purpose: This in vitro study investigated the effect of three light curing units on the temperature rise under 2 mm thick dentin during polymerization of different resin composite materials. Material and Methods: Three different light sources were used: A conventional halogen lamp (QTH), a plasma arc (Apollo 95E Elite) and a light-emitting diode (LED) light curing units. 90 dentin discs in 8 mm diameter and 2 mm thickness were obtained from freshly extracted premolar teeth. Fifteen disc-shaped specimens from each resin composite material (Admira, Filtek 60, Premise, Tetric Flow, Tetric Ceram and Filtek 250), 6 mm in diameter and 2 mm in depth, were placed on dentin discs in teflon molds (n=5). The specimens were irradiated with Standard mode of each light curing unit. A type-L thermocouple wire (Fe-Const.) connected to data logger (E-680) was used to record temperature rise which under dentin during polymerization by three different light sources. Data were analyzed by two-way ANOVA and Tukey tests. Results: Among all light curing units, the highest temperature rise was recorded with use of the halogen LCU, and the LED irradiation led to the lowest temperture rises. The highest temperature rise was observed for Admira and Tetric Flow resin composites, whereas the lowest temperature rise was for Premise. Conclusion: In all conditions tested, the temperature elevations were found to be lower than the critical value for pulpal injury reported in literature. Therefore, the LCUs used in this study could be safety for clinical situations mentioned before.   ÖZET Amaç: Bu in vitro çalışma üç farklı ışık kaynağının farklı rezin kompozit materyallerin polimerizasyonu sırasında 2 mm dentin altında oluşan ısı artışına etkisini araştırdı. Gereç ve Yöntem: Üç farklı ışık cihazı, bir halojen (QTH), bir plazma ark (Apollo 95E Elite) ve bir light-emitting diode (LED) kullanıldı. Yeni çekilmiş premolar dişlerden 8 mm çapında ve 2 mm kalınlığında 90 adet dentin disk hazırlandı. Her bir rezin kompozit materyalden (Admira, Filtek 60, Premise, Tetric Flow, Tetric Ceram and Filtek 250), 6 mm çap ve 2 mm derinlikte 15 örnek teflon moldda dentin üzerine yerleştirildi (n=5). Örnekler her bir ışık kaynağının standart modu ile polimerize edildi. Üniversal Girişli Gelişmiş Tarayıcı / Alarm Cihazına (E-680, Elimko Co., Turkey) bağlı bir Ltipi termokapl kablosu (Fe-Const.) polimerizasyon sırasında dentin altındaki ısı değişimlerini kaydetmek için kullanıldı. Veriler iki-yönlü varyans analizi ve Tukey testle değerlendirildi. Bulgular: Tüm ışık kaynakları arasında en yüksek ısı artışı halojen ışık kaynağı kullanımı ile kaydedilirken LED irradiasyon en düşük ısı artışına neden oldu. En yüksek ısı artışı Admira and Tetric Flow kompozitlerde gözlemlenirken, en düşük ısı artışı Premise için belirlendi. Sonuç: Test edilen tüm koşullarda ısı artışları pulpa hasarı için literatürde bildirilen kritik değerin altında bulundu. Dolayısıyla test edilen bu ışık kaynakları önceden belirtilen klinik koşullarda güvenle kullanılabilir. Anahtar kelimeler: Kompozit, polimerizasyon, ısı artış

The bite force and craniofacial morphology in patients with acromegaly: a pilot study

Objectives: Acromegaly is a metabolic disorder caused by increased growth hormone secretion. As a consequence of acromegaly some typical craniofacial morphology changes appear. This pilot study was conducted to compare the bite force and the characteristic size and shape of the craniofacial components of acromegalic patients with the healthy Turkish individuals. In additon, the correlations between bite force and craniofacial morphology of patients with acromegaly and control individuals were evaluated. Study Design: The maximum bite force of the participants was recorded with strain-gage transducer. Lateral xray scans were made under standard conditions, in centric occlusion. On cephalograms, the linear and angular measurements was performed. Results: Patients with acromegaly showed increased anterior and posterior total face height, ramus length, width of frontal sinuse, gonial angle and a negative difference between maxillary and mandibular protrusions. In addition, females with acromegaly showed larger lower anterior face height and sella turcica, decreased facial angle, increased mandibular plane angle. The cephalometric measurements, except one did not showed correlation with the bite force in acromegalic patients. In control group, significant correlations were observed between anterior total face height and anterior lower face height, mandibular plane angle and gonial angle. Conclusions: The greater changes were observed in the mandible. The maximum bite force of patients with acromegaly showed no difference from healthy individuals. The non-significant difference of bite force between healthy participants and acromegalic patients provide important information for dental treatment and prosthetic rehabilitation of acromegalic patients

Torus mandibularis varlığında kısmi dişsiz bir hastanın protetik rehabilitasyonu: olgu sunumu

The torus mandibularis is the one of the most common intraoral exostoses. It is often bilateral, occurs at the canin to premolar region on the lingual aspect of the mandible. It has been reported that the factors such as genetic and environmental factors, masticator hiperfunction, nutrition, race and ethnic groups might play role in occurence of them. Such type of bony protuberances may present many challenges when fabricating a removable partial or complete dentures. In this case report, after a general knowledge about mandibular tori, the prosthetic rehabilitation of a partially edentulous patient had bilaterally mandibular tori has been presented. ÖZET Torus mandibularis ağız içinde en sık görülen eksostoz türlerinden biridir. Genellikle, mandibulanın lingual yüzeyinde, kanin ve premolar bölgesinde yerleşim göstermesiyle karakterizedir. Etyolojisinde kalıtım, çevresel faktörler, artmış çiğneme fonksiyonu, beslenme, ırk ve etnik grup farklılıklarının etkili olduğu düşünülmektedir. Bu tür kemik büyümeleri hareketli parsiyel veya tam protez yapımında güçlüklere neden olabilir. Bu olgu sunumunda kısmi dişsiz ve çift taraflı mandibular torusa sahip bir hastanın protetik tedavisi bildirilmiş ve toruslar hakkında genel bilgi verilmiştir. Anahtar sözcükler: Torus mandibularis, kısmi dişsiz hast

Kompozit rezin materyallerin farklı ışık kaynaklarıyla polimerizasyonu sırasında oluşan ısısal değişikliklerin incelenmesi

<p><strong>Purpose:</strong> This in vitro study investigated the effect of three light curing units on the temperature rise under 2 mm thick dentin during polymerization of different resin composite materials.</p> <p><strong>Material and Methods:</strong> Three different light sources were used: A conventional halogen lamp (QTH), a plasma arc (Apollo 95E Elite) and a light-emitting diode (LED) light curing units. 90 dentin discs in 8 mm diameter and 2 mm thickness were obtained from freshly extracted premolar teeth. Fifteen disc-shaped specimens from each resin composite material (Admira, Filtek 60, Premise, Tetric Flow, Tetric Ceram and Filtek 250), 6 mm in diameter and 2 mm in depth, were placed on dentin discs in teflon molds (n=5). The specimens were irradiated with Standard mode of each light curing unit. A type-L thermocouple wire (Fe-Const.) connected to data logger (E-680) was used to record temperature rise which under dentin during polymerization by three different light sources. Data were analyzed by two-way ANOVA and Tukey tests.</p> <p><strong>Results:</strong> Among all light curing units, the highest temperature rise was recorded with use of the halogen LCU, and the LED irradiation led to the lowest temperture rises. The highest temperature rise was observed for Admira and Tetric Flow resin composites, whereas the lowest temperature rise was for Premise.</p> <p><strong>Conclusion:</strong> In all conditions tested, the temperature elevations were found to be lower than the critical value for pulpal injury reported in literature. Therefore, the LCUs used in this study could be safety for clinical situations mentioned before.</p> <p> </p> <p><strong>ÖZET</strong></p> <p><strong>Amaç:</strong> Bu in vitro çalışma üç farklı ışık kaynağının farklı rezin kompozit materyallerin polimerizasyonu sırasında 2 mm dentin altında oluşan ısı artışına etkisini araştırdı.</p> <p><strong>Gereç ve Yöntem:</strong> Üç farklı ışık cihazı, bir halojen (QTH), bir plazma ark (Apollo 95E Elite) ve bir light-emitting diode (LED) kullanıldı. Yeni çekilmiş premolar dişlerden 8 mm çapında ve 2 mm kalınlığında 90 adet dentin disk hazırlandı. Her bir rezin kompozit materyalden (Admira, Filtek 60, Premise, Tetric Flow, Tetric Ceram and Filtek 250), 6 mm çap ve 2 mm derinlikte 15 örnek teflon moldda dentin üzerine yerleştirildi (n=5). Örnekler her bir ışık kaynağının standart modu ile polimerize edildi. Üniversal Girişli Gelişmiş Tarayıcı / Alarm Cihazına (E-680, Elimko Co., Turkey) bağlı bir Ltipi termokapl kablosu (Fe-Const.) polimerizasyon sırasında dentin altındaki ısı değişimlerini kaydetmek için kullanıldı. Veriler iki-yönlü varyans analizi ve Tukey testle değerlendirildi.</p> <p><strong>Bulgular:</strong> Tüm ışık kaynakları arasında en yüksek ısı artışı halojen ışık kaynağı kullanımı ile kaydedilirken LED irradiasyon en düşük ısı artışına neden oldu. En yüksek ısı artışı Admira and Tetric Flow kompozitlerde gözlemlenirken, en düşük ısı artışı Premise için belirlendi.</p> <p><strong>Sonuç:</strong> Test edilen tüm koşullarda ısı artışları pulpa hasarı için literatürde bildirilen kritik değerin altında bulundu. Dolayısıyla test edilen bu ışık kaynakları önceden belirtilen klinik koşullarda güvenle kullanılabilir.</p> <p><strong>Anahtar kelimeler:</strong> Kompozit, polimerizasyon, ısı artışı</p&gt

Structure-property relation of a soft liner material used in denture applications

With a view to understanding the structure-property relation of a silicone-based soft lining denture material after polymerization, its chemical composition and viscoelastic properties were investigated. Chemical compositions of the cured and uncured polymers of a commercial silicone permanent soft liner were determined by infrared spectroscopic analysis, nuclear magnetic resonance (NMR), and X-ray photoelectron spectroscopy. Dynamic mechanical analysis (DMA) method was used to investigate the viscoelastic behavior of the cured polymer of liner

The effect of Esthetic fibers on impact resistance of a conventional heat-cured denture base resin

This study was conducted to observe the changes in impact resistance of a denture base resin reinforced with five types of fiber. E-glass, polyester, rayon, nylon 6, and nylon 6/6 fibers were cut into 2, 4, and 6 mm lengths and added into the resin at a concentration of 3% by weight. Five test specimens for each formulation, as well as control specimens without fiber, were prepared using a mold including a V-shaped notch with 55 x 10 x 10 mm dimensions. Impact tests were carried out using a Charpy-type tester. Additionally, surfaces of the impact sections were observed under a scanning electron microscope (SEM). Results indicated that impact energy tended to increase with fiber length, and that the highest value was recorded for rayon fiber-reinforced specimens of 6 mm length. E-glass fiber reinforcement produced relatively stable, high values for each length, whereby good interfacial strength between polymer matrix and glass fibers was confirmed by SEM analysis

Evaluation of laser treatment on reline-base composites

The effects of different laser treatments on some mechanical properties of acrylic resin and soft liner were investigated. A total of 60 test specimens were fabricated according to test requirements. The specimens were roughened with Potassium-ticanyl-Phosphate (KTP), Er:YAG, and Nd:YAG lasers before application of soft liner. The flexural, peel, and tensile bond strengths were measured using a universal testing machine. Fourier transform infrared spectroscopy with attenuated total reflectance (FTIR-ATR) spectra of surfaces were also obtained to evaluate changes on the lased surfaces. No significant difference was apparent between the tensile bond strength values of the groups. Although peel strength values obtained for each of the laser types were lower than those of the control group, flexural strength values were higher than those of the control specimens. The spectra of specimens showed that lasing led to some chemical changes on the resin surfaces. Physical changes on the treated surfaces were visualized by scanning electron microscopy (SEM) analysis. Results of this study suggest that such treatments may be warranted because of the increase in flexural strength