Reduced CT-derived erector spinae muscle area: a poor prognostic factor for short- and long-term outcomes in idiopathic pulmonary fibrosis patients.

AIM: To assess the relationship between idiopathic pulmonary fibrosis (IPF) prognosis, baseline skeletal muscle mass, and attenuation on computed tomography (CT) and clinical parameters. MATERIAL AND METHODS: This retrospective cohort study enrolled 195 patients. The mean follow-up duration was 42.52 months. Erector spinae muscle area (ESMA), pectoralis muscle area (PMA), and the attenuation of the erector spinae muscle at the level of T12 vertebrae were measured. Muscle indexes were obtained by adjusting the measured muscle areas to the patients' heights. The relationship between baseline CT-derived muscle metrics and clinical parameters including short- and long-term mortality were evaluated. RESULTS: There was a moderate correlation between ESMA and PMA and pectoralis muscle index (PMI; r=0.536, p<0001 and r=0.403, p<0.001 respectively). ESMA correlated significantly with forced expiratory volume in 1 second (FEV1; hazard ratio [HR] = 0.488 p<0.001) and forced vital capacity (FVC; HR=0.501, p<0.001). Compared with PMA, ESMA was more strongly associated with 1- and 2-year mortality in patients with IPF (HR=0.957, p=0.022). The survival rate in male patients with sarcopenia was significantly worse (p=0.040). CONCLUSION: ESMA measurements obtained from CT correlated with clinical parameters in IPF patients and were also predictors of short- and long-term survival.

The Influence of the Intraductal Carcinoma of the Prostate on the Short-Term Oncological Outcomes

Aim: The presence of intraductal carcinoma of the prostate (IDC-P) in radical prostatectomy (RP) specimens correlates with adverse prognostic factors such as worse biochemical recurrence-free survival, higher grade and stage disease. This study aimed to investigate the effect of IDC-P in radical prostatectomy specimens on short-term oncological outcomes. Materials and methods: Patients who underwent RP at our clinic for prostate cancer between May 2016 and November 2019 were included in the study. They were divided into two groups based on the presence of IDC-P in RP specimens. Their clinical, pathological, and oncologic data were evaluated retrospectively. Results: A total of 98 patients underwent RP with a mean age of 65.5 years (50-83) and a mean follow-up time of 31.2 months (6-52). Seventy and 28 patients were evaluated in the group without IDC-P and group with IDC-P, respectively. Surgical margin positivity (p=0.307) and lymph node metastasis (p=0.017) rates were higher in the group with IDC-P. Although there were no statistical differences between the groups, at follow-up biochemical recurrence rate (p=0.052) was higher, and mean time to biochemical recurrence rates were lower (p=0.057) in the group with IDC-P. The group with IDC-P was associated with a 3-fold increase in prostate cancer-specific mortality to the group without IDC-P (p=0.037). Conclusions: Patients with IDC-P at RP specimens have more advanced disease, shorter biochemical recurrence-free, and cancerspecific survival than those without IDC-P. Defining the presence of IDC-P in RP specimens is critical in choosing the appropriate treatment strategy and predicting the prognosis (AU)

Objetivo: La presencia de carcinoma intraductal dela próstata (IDC-P) en muestras de prostatectomía radical(RP) se correlaciona con factores de pronóstico adversotales como peor recurrencia bioquímica de supervivenciasin la enfermedad, así como mayor grado y estadío másavanzado de la enfermedad. El objetivo de este estudio erainvestigar el efecto de la IDC-P en muestras de prostatectomía radical en resultados oncológicos a corto plazo.Materiales y procedimientos: En este estudio hansido incluidos los pacientes que fueron sometidos a una RPdebido a cáncer de próstata en nuestra clínica entre mayodel 2016 y noviembre del 2019. Fueron divididos en dosgrupos según la presencia de IDC-P en sus muestras RP.Sus datos clínicos, patológicos y oncológicos fueron evaluados retrospectivamente.Resultados: Un total de 98 pacientes fueron sometidos a una RP con una edad media de 65,5 años (50-83) ycon un periodo de seguimiento medio de 31,2 meses (6-52). Se evaluaron 70 y 28 pacientes en el grupo sin IDCP y en el grupo con IDC-P, respectivamente. Dentro delgrupo con IDC-P, las tasas de positividad de margen quirúrgico (p=0,307) y metástasis en nodos linfáticos (p=0,017)son más elevadas. A pesar de no haber diferencias estadísticas entre ambos grupos, la tasa de recurrencia químicadurante el seguimiento (p=0,052) es más elevada y la tasadel tiempo medio hasta la recurrencia química (p=0,057)es menor en el grupo con IDC-P. El grupo con IDC-P hasido asociado a un aumento de la moralidad específica delcáncer de próstata 3 veces superior al del grupo sin IDC-P(p=0,037).Conclusiones: Los pacientes con IDC-P en las muestras RP se encuentran en en estadío de la enfermedad másavanzada, así como una recurrencia bioquímica sin la enfermedad y una supervivencia específica más cortas que aquellos sin IDC-P. La determinación de la presencia de IDC-Pen muestras RP es crítica a la hora de elegir una estrategiade tratamiento adecuada y la predicción del pronóstico (AU)

Assesment of accessory branches of canalis sinuosus on CBCT images.

BACKGROUND: The aim of this study is to describe the presence, to reveal the frequency and characteristics of accessory canals (ACs) of the canalis sinuosus (CS) by cone beam computed tomography (CBCT). MATERIAL AND METHODS: A total of 326 CBCT examinations were scanned retrospectively. The anatomical views were evaluated on sagittal, axial, coronal and cross sectional imaging. The following parameters were recorded: age, sex, presence or absence of ACs, location in relation to the adjacent teeth and distance to the nasal cavity floor (NCF), alveolar ridge crest (ARC) and buccal cortical bone (BCB), and incisive canal. All the collected data were statistically analyzed. RESULTS: 113 patients (34,7%); presented ACs in total 214 foramina of the sample. There were no statistically significant changes in the presence of ACs regarding age groups excluding 80-89 years. But there is a statistically significant difference regarding the frequency of ACs and the gender. The prevalence for male patients was higher than female patients. Curved-shape configuration of CS prevalence is found as 69,15%. The prevalence of vertical tracing is 26,16% and Y-shape configuration of CS prevalence is 4,67%. Diameter of the foramens of the CS branches was 1.30 mm. The mean distance of the AC to the NCF, BCB, and ARC were found 13,83 mm, 6,60 mm and 5,32 mm, respectively. CONCLUSIONS: In the anterior palatal region, ACs are mostly related to CS's branches. So; knowing the course of CS branches in surgical planning and radiographic evaluations in this region is extremely important for preventing complications and avoiding misdiagnosis.

Randomized clinical trial of short or long interval between neoadjuvant chemoradiotherapy and surgery for rectal cancer.

BACKGROUND: The optimal timing of surgery following preoperative chemoradiotherapy (CRT) is controversial. This trial aimed to compare pathological complete response (pCR) rates obtained after an interval of 8 weeks or less versus more than 8 weeks. METHODS: Patients with locally advanced rectal adenocarcinoma situated within 12 cm of the anal verge (T3-4 or N+ disease) were randomized to undergo total mesorectal excision (TME) within 8 weeks (classical interval, CI group) or after 8 weeks (long interval, LI group) following CRT. RESULTS: Among the 327 included patients (CI 160, LI 167), the pCR rate was significantly higher in the LI group than in the CI group (10·0 versus 18·6 per cent; P = 0·027). The highest pCR rate (29 per cent) was observed between 10 and 11 weeks. There was statistically significant disease regression in the LI group, with better stage (P = 0·004) and T category (P = 0·001) than in the CI group. There was no significant difference in surgical quality (rates of tumour-positive margins, TME quality, anastomotic leakage and intraoperative perforation) between the groups. The overall morbidity rate was 22·5 per cent in the CI group and 19·8 per cent in the LI group (P = 0·307). Regression analysis including sex, age, clinical stage, tumour location, tumour differentiation, TME quality, concomitant chemotherapy and interval to surgery revealed no statistically significant predictors of pCR. CONCLUSION: Disease regression and pCR rate are increased with an interval between CRT and surgery exceeding 8 weeks. Registration number: NCT03287843 (http://www.clinicaltrials.gov).

The relationship between the second-to-fourth digit ratios and lifelong premature ejaculation: a prospective, comparative study.

To investigate the relationship between the fetal androgen exposure and lifelong premature ejaculation by using the ratio of the second (index)-to-fourth (ring) digits (2D : 4D) which is the marker for higher prenatal androgen exposure. Totally 65 patients with lifelong premature ejaculation and 65 control cases without any ejaculatory complaints were enrolled in the study. A detailed medical history was obtained and self-estimated intravaginal ejaculatory latency times were recorded. Ejaculation function was evaluated by Premature Ejaculation Diagnostic Tool. The lengths of the second and fourth digits of both hands were measured and 2D : 4Ds were calculated. The mean 2D : 4D values were 0.964 ± 0.024 vs. 0.978 ± 0.032 (p = 0.004) for the right hand and 0.966 ± 0.023 vs. 0.979 ± 0.032 (p = 0.006) for the left hand in lifelong premature ejaculation and control groups, respectively. Significant correlations were observed between the digit ratios and self-estimated intravaginal ejaculatory latency time (r = 0.258, p = 0.003 for right hand; r = 0.240, p = 0.06 for left hand), and between the digit ratios and total Premature Ejaculation Diagnostic Tool scores (r = -0.263, p = 0.003 for right hand; r = -0.238, p = 0.06 for left hand). Individuals with lower digit ratios have higher risks of shorter intravaginal ejaculatory latency times. These results suggest that increased fetal androgen exposure may be a new risk factor for the development of lifelong premature ejaculation.

Comparison of Bone Resorption Rates after Intraoral Block Bone and Guided Bone Regeneration Augmentation for the Reconstruction of Horizontally Deficient Maxillary Alveolar Ridges.

Purpose. Bone atrophy after tooth loss may leave insufficient bone for implant placement. We compared volumetric changes after autogenous ramus block bone grafting (RBG) or guided bone regeneration (GBR) in horizontally deficient maxilla before implant placement. Materials and Methods. In this retrospective study, volumetric changes at RBG or GBR graft sites were evaluated using cone-beam computed tomography. The primary outcome variable was the volumetric resorption rate. Secondary outcomes were bone gain, graft success, and implant insertion torque. Results. Twenty-four patients (28 grafted sites) were included (GBR, 15; RBG, 13). One patient (RBG) suffered mucosal dehiscence at the recipient site 6 weeks after surgery, which healed spontaneously. Mean volume reduction in the GBR and RBG groups was 12.48 ± 2.67% and 7.20 ± 1.40%, respectively. GBR resulted in significantly more bone resorption than RBG (P < 0.001). Mean horizontal bone gain and width after healing were significantly greater in the GBR than in the RBG group (P = 0.002 and 0.005, resp.). Implant torque was similar between groups (P > 0.05). Conclusions. Both RBG and GBR hard-tissue augmentation techniques provide adequate bone graft volume and stability for implant insertion. However, GBR causes greater resorption at maxillary augmented sites than RBG, which clinicians should consider during treatment planning.

Effects of losartan on experimental varicocele-induced testicular germ cell apoptosis.

To investigate the potential protective effects of losartan on varicocele-induced germ cell apoptosis, 24 adult male Sprague Dawley rats were divided into three groups: a sham operation was performed in SHAM group, and experimental left varicocele was created in VAR and VAR + LOS groups. Additionally, in VAR + LOS group, losartan was administered for 30 days starting on the day of surgery. At the end of 30 days, all animals were sacrificed and left orchiectomy was performed. Testicular injury and spermatogenesis were evaluated according to Johnsen scoring system. To assess the nitrosative stress, immunohistochemical staining for endothelial nitric oxide synthase was used and evaluated by H-score and apoptotic index (AI) of germ cells was analysed by TUNEL method. A significant decrease in the mean Johnsen score (JS) was observed in VAR group compared with SHAM (p < .001). The mean H-score and AI were significantly higher in VAR group compared with SHAM (p < .001). After losartan administration, mean JS was significantly increased (p < .001) and mean H-score and AI were significantly decreased compared with VAR group (p < .001 and .01, respectively). Findings of this suggest that losartan acts as a potent protective agent against varicocele-induced germ cell apoptosis.

Soft tissue augmentation of ridge defects in the maxillary anterior area using two different methods: a randomized controlled clinical trial.

OBJECTIVES: To test whether or not vascularized interpositional periosteal-connective tissue grafts are as successful as free subepithelial connective tissue grafts in augmenting volume defects in the anterior maxilla. MATERIAL AND METHODS: Twenty subjects with Seibert class 1 ridge defects in the anterior maxilla were randomly, equally assigned to augmentation by vascularized interpositional periosteal-connective tissue graft (test) or free subepithelial connective tissue graft (control). Clinical periodontal parameters at teeth adjacent to the gap were recorded, and conventional impressions were taken prior to surgery (baseline = t(0)) and 1 (t(1)), 3 (t(3)) and 6 (t(6)) months after surgery. The casts were optically scanned, digitized and analyzed for ridge contour changes in the augmented area. Data were subjected to nonparametric statistics. RESULTS: The contour changes in labial distance between baseline and follow-up for the control group were (median, range) 1 mm, 0.37-1.45 (t(0)-t(1)); 1.18 mm, 0.39-1.40 (t(0)-t(3)); and 0.63 mm, 0.28-1.22 (t(0)-t(6)) and for test group 1.21 mm, 0.74-2.47 (t(0)-t(1)); 1.26 mm, 0.50-1.71 (t(0)-t(3)); and 1.18 mm, 0.16-1.75 (t(0)-t(6)). Significantly less shrinkage of the graft was observed in the test group after 6 months (P = 0.03). Clinical periodontal parameters at the neighboring teeth were stable over the follow-up period and did not differ between groups. CONCLUSIONS: Augmentation of single tooth gaps with moderate ridge defects in the anterior maxilla was successfully performed using both techniques. However, after 6 months, sites treated by the pediculated graft were superior in maintaining the initially augmented volume and showed less shrinkage of the graft. This could be attributed to better perfusion of the pediculated graft.

Prognostic factors of survival and recurrence pattern in differentiated thyroid cancer: a retrospective study from Western Turkey.

OBJECTIVES: The aim of this study was to determine prognostic factors in patients with well-differentiated thyroid cancer (WDTC). METHODS: This retrospective study included 181 well-differentiated thyroid cancer patients who were operated between Decembers 1996-2007. Total of 181 patients [139 (76.8%) women and 42 (23.2%) men with a mean age of 46.3 years] who were subjected to a complete follow-up, were enrolled in the study. The mean follow-up period was 7.1 years (range 3.1 to 14.9 years). Medical records were reviewed regarding to age, gender, extent of surgery, tumor size, multifocality, clinical stage, capsule infiltration, extracapsular invasion, histological type, lymph node metastasis, distant metastasis, radioactive iodine treatment and prognosis. RESULTS: During follow-up, in 41 (22.6%) patients locoregional recurrences were detected and 5 (2.7%) patients passed away. Determined statistically significant prognostic factors were as follows; tumor size (histopathologically), extent of surgery, histological type, lymph node metastasis, tumor invasion (capsule and extracapsular) and clinical stage. CONCLUSIONS: Well-differentiated thyroid cancer is a disease with good prognosis when detected early and appropriate treatment applied. Despite the prognosis, it is good to apply the right treatment and reduce recurrence and mortality rates, prognostic factors are well known and must be considered in patient management.

Extending the Lincoln-Petersen estimator for multiple identifications in one source.

The Lincoln-Petersen estimator is one of the most popular estimators used in capture-recapture studies. It was developed for a sampling situation in which two sources independently identify members of a target population. For each of the two sources, it is determined if a unit of the target population is identified or not. This leads to a 2 × 2 table with frequencies f11 ,f10 ,f01 ,f00 indicating the number of units identified by both sources, by the first but not the second source, by the second but not the first source and not identified by any of the two sources, respectively. However, f00 is unobserved so that the 2 × 2 table is incomplete and the Lincoln-Petersen estimator provides an estimate for f00 . In this paper, we consider a generalization of this situation for which one source provides not only a binary identification outcome but also a count outcome of how many times a unit has been identified. Using a truncated Poisson count model, truncating multiple identifications larger than two, we propose a maximum likelihood estimator of the Poisson parameter and, ultimately, of the population size. This estimator shows benefits, in comparison with Lincoln-Petersen's, in terms of bias and efficiency. It is possible to test the homogeneity assumption that is not testable in the Lincoln-Petersen framework. The approach is applied to surveillance data on syphilis from Izmir, Turkey.

Effects of different surface treatments on bond strength between resin cements and zirconia ceramics.

This study compares the bond strength of resin cement and yttrium-stabilized tetragonal zirconia polycrystalline (Y-TZP) ceramic with different surface conditioning methods. Two hundred presintered Y-TZP ceramic specimens were prepared, sintered (4 × 4 × 4 mm), and randomly assigned to four equal groups as control (C, no conditioning); airborne particle abraded (APA, air abrasion with 11 µm Al2O3); tribochemical silica coating/silane coupling system (TSC, Rocatec, air abrasion with 110 µm Al2O3, 30 µm silica-coated Al2O3 and silane); and laser (L, Er:YAG laser irradiation treated at a power setting of 200 mJ). After specimen preparation, composite resin cylinders were prepared and cemented with resin cements (Clearfil Esthetic, Panavia F 2.0, Rely X-U100, Super Bond C&B, and Multilink Automix) on the ceramic surfaces and kept in an incubator at 37°C for 60 days. All specimens were tested for shear bond strength with a universal testing machine, and fractured surfaces were evaluated by environmental scanning electron microscopy. Statistical analysis was performed using Kruskal-Wallis and Mann-Whitney U-tests (α=0.05). The bond strengths for C and L groups were not significantly different according to adhesive resin cement. APA and TSC resulted in increased bond strength for Panavia F 2.0 and Rely X-U100 resin cements. Additionally, TSC presented higher bond strength with Multilink Automix. Adhesive fracture between the ceramic and resin cement was the most common failure. Complete cohesive fracture at the ceramic or composite cylinders was not observed. Regardless of the adhesive resin cement used, laser treatment did not improve resin bond strength.

Diagnosing metabolic syndrome in type 2 diabetic Turkish patients: comparison of AHA/NHLBI and IDF definitions.

OBJECTIVES: The objective of this study was to determine the percentage of metabolic syndrome (MetS) in a Turkish population with type 2 diabetes mellitus (T2DM) according to the American Heart Association/National Heart, Lung, and Blood Institute (AHA/NHLBI) and International Diabetes Federation (IDF) definitions and to assess the agreement among these definitions. BACKGROUND: It is essential to identify the prevalence of MetS in diabetic patients, as MetS is a stronger risk factor for cardiovascular disease in patients with T2DM than in non-diabetic subjects. METHODS: 235 consecutive patients with T2DM were included in the study. The MetS was defined according to AHA/NHLBI and IDF definitions. Cohen's kappa was used as a measure of agreement between the two definitions. Logistic regression analysis was performed to calculate the odds ratios. RESULTS: The percentage of MetS was 85.1% by AHA/NHLBI and 87.2% by IDF criteria. The agreement between AHA/NHLBI and IDF was fairly good (kappa = 0.55). Females were more affected than males. When the frequencies of each individual feature of the MetS according the definitions were assessed, hypertension was the most common feature in males, whilst abdominal obesity was in females. Serum triglyceride and waist circumference had the highest predictive ability for MetS according to AHA/NHLBI and IDF definitions, respectively. CONCLUSION: The MetS is a common condition among diabetic patients. Since diabetic patients carry a cluster of cardiovascular risk factors, correct identification of the MetS among this population is of great importance, for an integrated approach to reduce the high costs and the associated disabilities (Tab. 5, Fig. 2, Ref. 54).

Smoking and matrix metalloproteinases, neutrophil elastase and myeloperoxidase in chronic periodontitis.

OBJECTIVES: To investigate possible relationship between smoking and serum concentrations of matrix metalloproteinase-8,-9 (MMP-8, MMP-9), tissue inhibitor of matrix metalloproteinases-1 (TIMP-1), neutrophil elastase (NE), myeloperoxidase (MPO) in chronic periodontitis (CP) patients relative to periodontally healthy subjects. METHODS: Serum samples were obtained from 111 subjects before initiation of any periodontal intervention. Fifty-five CP patients (39 non-smokers, 16 smokers) and 56 periodontally healthy subjects (39 non-smokers, 17 smokers) were recruited. Serum concentrations of MMP-8 were determined by IFMA and MPO, MMP-9, TIMP-1, NE concentrations by ELISA. ANCOVA and Pearson correlation analysis was utilized for statistical analysis. RESULTS: Serum MPO, NE concentrations were higher in smoker CP than non-smoker CP patients (P=0.002 and P<0.001, respectively), whereas these were similar in smoker, non-smoker periodontally healthy groups (P > 0.05). TIMP-1 concentration was higher in non-smoker CP than smoker CP group (P<0.05). MMP-9/TIMP-1 ratios were higher in smoker CP than non-smoker CP group (P=0.01). MMP-8 concentrations, MMP-8/TIMP-1 and MMP-9/TIMP-1 ratios in CP group were not significantly different from those in periodontally healthy group (P>0.05). CONCLUSIONS: Our findings of significantly elevated serum MMP-9, MPO, NE together with decreased TIMP-1 in smoker CP patients than non-smokers support that smoking together with periodontal destruction may expose/predispose to cardiovascular diseases.

Plasma osteoprotegerin levels are decreased in smoker chronic periodontitis patients.

BACKGROUND: The aim of this study was to evaluate plasma levels of soluble receptor activator of nuclear factor-kappa B ligand (sRANKL) and osteoprotegerin (OPG) in smoker versus non-smoker chronic periodontitis patients. METHODS: Plasma samples were obtained from 13 smoker and 31 non-smoker systemically healthy chronic periodontitis patients, as well as 13 smoker and 29 non-smoker systemically and periodontally healthy subjects. Before commencing any periodontal intervention, venous blood samples were obtained and whole-mouth clinical periodontal measurements were recorded. sRANKL and OPG concentrations in plasma samples were determined by enzyme-linked immunosorbent assay (ELISA) technique. Data were tested statistically by student's t test, Wilcoxon matched pairs test, and Spearman's correlation analysis. RESULTS: All clinical periodontal measurements were significantly higher in chronic periodontitis groups than the healthy controls (p < 0.05). Smoker and non-smoker chronic periodontitis patients exhibited similar values in all clinical periodontal measurements and plasma sRANKL, OPG concentrations (p > 0.05). Smoker chronic periodontitis patients exhibited significantly lower (p = 0.007) plasma OPG concentrations and higher sRANKL/OPG ratio (p = 0.01) than smoker healthy controls. CONCLUSIONS: Within the limits of this study, periodontal inflammation in smoker chronic periodontitis patients seems to lower plasma osteoprotegerin levels and thereby increase the RANKL/OPG ratio, and possibly play a role in the increased susceptibility for alveolar bone destruction in smoker subjects.

Effectiveness of HERO 642 versus Hedström files for removing gutta-percha fillings in curved root canals: an ex vivo study.

AIM: To compare the effectiveness of gutta-percha removal and the maintenance of canal anatomy when using the HERO 642 system or Hedström files (H-files) in mandibular molar teeth. METHODOLOGY: The root canals of 40 mandibular molar teeth were instrumented using H-files and filled with gutta-percha and sealer. After 1 year in storage, the roots were sectioned horizontally to provide apical, middle and coronal root thirds. Sections were photographed, and an individual muffle was produced for each tooth. Teeth were randomly divided into four groups (n = 10) and the gutta-percha removed using either the HERO 642 system or H-files, with or without solvent. Digital images of the root canals were then re-taken. Root thirds were inspected for lateral perforations, and the percentage of the residual canal filling was determined on postoperative images. Transportation and centring ratio were calculated using preoperative and postoperative images of the cross-sections of root thirds. RESULTS: H-files groups were associated with less filling material than the HERO 642 system (H-files-HERO 642 P = 0.056, H-files-HERO 642+solvent P = 0.041, H-files + solvent-HERO 642 P = 0.018, H-files + solvent-HERO 642 + solvent P = 0.016). The percentage of residual filling material was similar in the apical thirds, and the contribution of solvent to canal debridement was not statistically significant (P > 0.05). Perforation occurred mesiobuccally in 48% of specimens in the apical sections of mesial roots. There were no significant differences for centring ratio, transportation and perforation rate between groups. CONCLUSIONS: H-files left less gutta-percha overall; however, there was no difference in the apical third. The effect of solvent was not remarkable. Both instrument systems created a large number of perforations.

Boron removal from aqueous solutions by ion-exchange resin: column sorption-elution studies.

A column sorption-elution study was carried out by using a strong base anion-exchange resin (Dowex 2 x 8) for the removal of boron from aqueous solutions. The breakthrough curve was obtained as a function of feed flow rate and the total and breakthrough capacity values of the resin were calculated. The boron on the resin was quantitatively eluted with 0.5M HCl solution at different flow rates. Three consecutive sorption-elution-washing-regeneration-washing cycles were applied to the resin in order to investigate the reusability of the ion-exchange resin. Total capacity values remained almost the same after three sorption-elution-regeneration cycles. The Thomas and the Yoon-Nelson models were applied to experimental data to predict the breakthrough curves and to determine the characteristic column parameters required for process design. The results proved that the models would describe the breakthrough curves well.

Digital analysis of mouthrinses' staining characteristics on provisional acrylic resins.

Provisional restorations are expected to be both aestethically and physically durable during the preparation of permanent restorations. In this study, the staining properties of mouthrinses containing chlorhexidine gluconate, benzydamine hydrochloride and a hybrid mouthrinse were investigated on light and dark shades of a provisional acrylic resin. Totally 80 specimens were prepared and were photographed digitally to obtain the baseline L*, a*, b* values. Each sample was immersed in test solutions for 12 h which was equivalent time to 1 year of mouthrinse use, and the post-treatment images of the test materials were acquired. All L*, a*, b* values were analysed by a graphic software, and the total colour change (DeltaE*) of each specimen was calculated. Also the same colour analyses were performed on all test solutions to establish their colour parameters. Analysis of variance and Tukey's tests were used for statistical analyses and alpha was 0.05. All test solutions produced perceptible staining on the provisional material, with DeltaE values over 3.7. In both shades, hybrid rinse caused the highest staining (DeltaE=5.705), and was followed by chlorhexidine gluconate rinse, with DeltaE value of 4.120. The third highest staining was observed with benzydamine hydrochloride rinse (DeltaE=3.959), whereas the control caused the least staining (DeltaE=3.095). The lighter shade provisional material resulted with clinically observable staining even when immersed in distilled water; however, the dark shades showed clinically perceptible staining solely with the hybrid mouthrinse. In this study, the shade of the acrylic material was the determinator of the staining process.