Examination of paramolar tubercles in Turkish population using cone beam computed tomography / Estudio de los tuberculos paramolares en una población turca mediante tomografía computarizada de haz cónico

SUMMARY: Paramolar tubercle (PT) is an additional cusp occuring on buccal surface of both upper and lower permanent molars. PT is also known as parastyle when tubercle is present in upper molars, as protostylid when tubercle is present in lower molars. The aim of this study was to evaluate prevalence of PTs in Turkish population with cone beam computed tomography (CBCT). Presence of PT in molar teeth were evaluated retrospectively using CBCT images of 210 patients (102 male, 108 female) between 18-77 years old. A total of 909 teeth were analyzed. Because of various reasons some teeth were excluded and final analyze was done with 653 teeth. Prevalence of PT was found as 2.76 % (18 out of 653). Highest frequency of PT was detected 5 in #27, 4 in #17, 2 in #48 among all molar teeth respectively. In two cases; 2 PTs were on the same tooth, bilateral PT was found only in one case. PT was undetected on upper first molars. Prevalence of PTs on permanent molars is a rare phenomenon in the studied population. Use of CBCT in such anatomic variations will provide valuable and detailed information during treatment modalities. Since this pilot study represents Turkish subpopulation, comprehensive studies with increased number of cases should be undertaken to clarify the prevalence of paramolars in Turkish population. Advanced imaging techniques like CBCT will be more helpful in understanding and detecting exact morphological and anatomical variations of PTs during treatment modalities.

RESUMEN: El tubérculo paramolar (TP) es una cúspide adicional que está en la superficie vestibular de los molares permanentes superiores e inferiores. El objetivo de este estudio fue evaluar la predisposición de TP en la población turca con tomografía computarizada de haz cónico (TCHC). Presencia de TP en dientes molares se evaluaron retrospectivamente utilizando imágenes de tomografia de 210 pacientes (102 hombres, 108 mujeres) entre 18-77 años de edad. Se analizó un total de 909 dientes. Por varias razones, algunos dientes fueron excluídos y el análisis final se realizó con 653 dientes. Prevalencia de PTP se encontró en el 2,76 % (18 dientes de 653). La frecuencia más alta de TP se detectó: 5 en # 27, 4 en # 17, 2 en # 48, entre todos los dientes molares, respectivamente. En dos casos, 2 de los TP fueron observados en el mismo diente; TP bilateral sólo se encontró en un caso. El TP no fue detectado en los primeros molares superiores. La prevalencia de TP en los molares permanentes es un fenómeno poco frecuente en la población estudiada. El uso de la TCHC en tales variaciones anatómicas, proporcionará información valiosa y detallada para definir la aplicación de diferentes modalidades de tratamiento. Dado que este estudio piloto representa a una subpoblación turca, estudios exhaustivos con un mayor número de casos deben llevarse a cabo para determinar la prevalencia en la población turca total. Técnicas avanzadas de imagen como TCHC serán más útiles para detectar variaciones morfológicas y anatómicas exactas de TP durante diversas modalidades de tratamiento.

Color Stability of Composites After Short-term Oral Simulation: An in vitro Study.

BACKGROUND: Although most of the studies investigated color stability of different restorative materials, evaluation of color stability of composites after immersion in multiple beverages in the same day by an in vitro oral simulation study is unclear. OBJECTIVE: To assess color change of different restorative materials at the end of days 1, 14, and 30 of immersion in multiple liquid types to mimic the oral environment in vitro. METHOD: Ten disc-shaped specimens were made from each of four different resin composites (Filtek Z250, Voco x-tra base, Beautifil Flow Plus, Beautifil II). Baseline color value of each sample was measured using a spectrophotometer. Each composite was respectively immersed in coffee, an orange/pomegranate juice mixture, black tea, and a mouth rinse on the same day to mimic daily liquid consumption of individuals. Color measurements were taken after 1, 14, and 30 days by spectrophotometer and color change values were calculated. Statistical analyses were executed by one-way ANOVA/Tukey HSD and repeated-measures ANOVA. RESULTS: All materials showed significant color change after 1, 14, and 30 days (P < 0.01) of immersion in liquids, with the lowest color alteration observed at the 1st day and the highest observed after the 30th day. Among the materials tested, at each time point (1, 14, and 30 days), the lowest color alteration was detected in Filtek Z250 and the highest color alteration was detected in Beautifil II. CONCLUSION: Color alteration of composite resins is affected by composite type and storage time. With the exception of 1 day of storage, color changes of all materials were substantial and clinically unacceptable.

Influence of operator experience on in vitro bond strength of dentin adhesives.

PURPOSE: To examine the influence of operator experience level on shear bond strength (SBS) of a self-etching adhesive (Clearfil SE Bond [CSE], Kuraray) and an etch-and-rinse adhesive (Single Bond [SB], 3M ESPE). MATERIALS AND METHODS: Flat dentin surfaces were created on 120 extracted human third molars. Bonding agents and composite resin were applied and light cured according to manufacturers' directions (n = 15). Four operators with different levels of experience in operative dentistry performed the same specimen preparation steps independently: group 1: specialist in operative dentistry; group 2: post-graduate student; group 3: undergraduate dental student; group 4: private general practitioner. Specimens were stored in distilled water for 24 h at 37°C before SBS testing. Statistical analyses were carried out with Mann-Whitney U- and Kruskall-Wallis tests. RESULTS: For CSE, mean SBS and standard deviations were: (1) 54.4 ± 15.6(a), (2) 55.3 ± 7.6(a), (3) 49.4 ± 10.5(ab), (4) 41.6 ± 13.1(b). For SB, they were: (1) 28.6 ± 10.3(c), (2) 32.7 ± 11.2(c), (3) 17.5 ± 5.6(d), (4) 24.4 ± 9.5(cd). Groups with the same superscript letters are not significantly different. CSE showed higher bond strengths than SB in all groups (p < 0.05). There was no significant difference in mean bond strengths between groups 1 and 2 for each adhesive (p > 0.05). Depending on the adhesives, groups 3 and 4 were significantly different from groups 1 and 2, but not different from each other. CONCLUSION: Operator experience influences dentin bond strength values of dentin adhesives. An increased level of experience with a specific adhesive system and the associated application procedures correlates with higher SBSs.

Evaluation of cytotoxic effects of six self-etching adhesives with direct and indirect contact tests.

This study evaluated the cytotoxicity of self-etching primers/adhesives by direct contact and dentin barrier tests. The three two-step self-etching systems Clearfil SE Bond (CSE), Clearfil Protect Bond (CPB), Prime&Bond NT/NRC (PB) and one-step self-etching systems Reactmer Bond (RB), Clearfil Tri-S Bond (CTS), and Adper Prompt L-Pop (AP) were examined. In direct contact tests, L929 cells were cultured in the presence of diluted solutions (50, 20, 10, and 1%) of primer/conditioner of adhesive systems. For dentin barrier tests, each system was applied onto 0.5 or 1.5 mm thick human dentin assembled in a simple pulp chamber device and incubated for 24 h at 37°C to make the diffusive components contact the L929 cells placed at the bottom of the chamber. The cytotoxic effects were assessed by MTT assay. Cell culture without application of any primers/adhesives served as the control for both tests. One-way ANOVA and Tukey HSD tests were used for statistical analyses. The direct contact tests demonstrated that CSE and CPB were less toxic than the other materials at all dilutions. In the dentin barrier tests, toxic effects of materials were reduced with an increase in thickness of intervening dentin. CSE and CPB showed less cytotoxicity than the other adhesives (p<0.05) when applied to 0.5 mm-thick dentin, and CSE was the least toxic in the 1.5 mm-dentin group (p<0.05). Dentin thickness positively affected biocompatibility of the tested bonding systems. Two-step self-etching systems with HEMA-based primers were more biocompatible than other self-etching adhesives.

Effect of different finishing techniques for restorative materials on surface roughness and bacterial adhesion.

STATEMENT OF PROBLEM: The formation of biofilm and bacterial accumulation on dental materials may lead to the development of gingival inflammation and secondary caries. PURPOSE: The purpose of this study was to examine the effect of different surface finishing and polishing methods on surface roughness and the adhesion of S. mutans bacteria to 2 new-generation indirect composite resins, 1 direct composite resin, and 1 ceramic material. MATERIAL AND METHODS: Forty specimens (10 x 10 x 2 mm) of each material, indirect composite resins (SR Adoro, Estenia), direct composite resin (Tetric), and a ceramic material (VITABLOCS Mark II), were fabricated. Specimens were divided into 4 groups (n=10) that were treated with 1 of the following 4 surface finishing techniques: diamond rotary cutting instrument, sandpaper discs (Sof-Lex), silicone-carbide rubber points (Shofu), or a felt wheel with diamond paste. Surface roughness was measured with a profilometer. Test specimens were covered with artificial saliva and mucin to produce pellicle. Bacterial suspension (10(9) CFU/ml) was then added to the pellicle-coated specimens, and bacterial adhesion was determined using a confocal laser microscope and image analyzing program. Data were analyzed with 2-way ANOVA, followed by Tukey HSD test, Pearson correlation, and regression analysis (alpha=.05). RESULTS: The highest surface roughness values were recorded in SR Adoro and diamond rotary cutting instrument groups. The lowest vital S. mutans adhesion was seen in the ceramic group and in SR Adoro indirect composite resin (P<.05). CONCLUSIONS: Bacterial adhesion to indirect composite resin materials differed from that to ceramic material after surface treatments. A positive correlation was observed between surface roughness and the vital S. mutans adhesion.