Factors affecting the rates of incidental parathyroidectomy during thyroidectomy.

BACKGROUND: The most important factors affecting the development of postoperative hypocalcaemia (PH) include intraoperative trauma to the parathyroid glands, incidental parathyroidectomy (IP), and the surgeon's experience. In this study, we aimed to determine the incidence of IP, evaluate its effect on postoperative calcium levels and investigate the effect of surgeon experience and volume on IP incidence and postoperative calcium levels. METHODS: This retrospective study included 645 patients who underwent thyroid surgery at the Department of General Surgery, Kütahya Health Sciences University between September 2016 and March 2020. All patients underwent surgery at a single clinic by general surgeons experienced in thyroid surgery and their residents (3-5 years). RESULTS: Normal parathyroid glands were reported in 58 (8.9%) of 645 patients. In 5 (8.6%) of 58 patients the parathyroid gland was detected in the intrathyroidal region. PH developed in ten patients (17.2%) with incidental removal of the parathyroid glands. A statistically significant difference was found between the number of incidentally removed parathyroid glands and the development of hypocalcaemia (p<0.05). Normal parathyroid glands were reported in the pathology of 37 (7.9%) patients operated on by general surgeons and 22 (12.6%) patients operated on by their residents. PH developed in 39 (8.2%) patients operated on by general surgeons and in 8 (4.5%) patients operated on by their residents. CONCLUSIONS: We found that the complication rate during the resident training process was the same as that of experienced general surgeons. A thyroidectomy can be safely performed by senior residents during residential training.

The effect of the visceral adiposity index on the severity of COVID-19 disease: results of a cross-sectional study.

OBJECTIVE: Obesity has been identified as a contributing factor that exacerbates the severity of COVID-19 and is associated with an increased risk of mortality among hospitalized patients. Assessing visceral adipose tissue cannot be solely determined by obesity and body mass index (BMI) alone. In our study, we investigated the relationship between the visceral adiposity index (VAI) and the clinical severity of COVID-19. PATIENTS AND METHODS: A total of 315 adult patients hospitalized with COVID-19 were included in the study. The cohort consisted of 146 male patients, and the median age was 60 (48-74) years. Comparative analyses were conducted to evaluate gender-based differences in VAI levels and the impact of VAI on the extent of radiological lung involvement. RESULTS: The median VAI level was significantly higher in women compared to men (6.1 vs. 4.0, p<0.001). Furthermore, patients with radiologically severe lung involvement demonstrated a higher median VAI level compared to those with mild involvement (5.7 vs. 4.2, p=0.003). This difference was particularly notable among male patients, where the median VAI level was significantly higher. Logistic regression analysis revealed that each integer increase in the median VAI value was associated with a 1.1-fold (1.01-1.14) increase in the severity of radiological lung involvement (p=0.011). CONCLUSIONS: Our study highlights a significant correlation between VAI and the clinical severity of COVID-19, particularly among male patients. The findings suggest that VAI, as an indicator of visceral adiposity, holds potential as a valuable tool for assessing COVID-19 severity and identifying high-risk individuals, particularly males.

Reducing oxidative stress by κ-carrageenan and C60HyFn: The post-thaw quality and antioxidant status of Azari water buffalo bull semen.

Azeri water buffalo is a species of great interest due to the high quality of its products such as milk. Due to the decreasing trend of its number and risk of extinction in the future, our attention is directed towards ensuring the preservation of its genetic reserves by keeping its sperm. Using antioxidants in semen extender is one of the ways to reduce the detrimental effects of freezing process on post-thawed quality of spermatozoa. This study was conducted to determine the effect of κ-carrageenan (k-CRG) and C60HyFn supplemented semen extender on the quality of post-thawed Azari water buffalo spermatozoa. A total of 30 semen samples were obtained from three buffaloes using an artificial vagina (twice a week for five weeks = 10 replicates). The samples (n = 3) from each replicate were pooled and divided into equal aliquots to prepare 14 extender groups, including control (C), k-0.2, K-0.4, K-0.6, K-0.8 (containing 0.2, 0.4, 0.8 mg K-CRG/mL, respectively), C-0.1, C-0.2, C-0.4, C-0.8, C-1, C-5, C-10, C-20, and C-40 (containing 0.1, 0.2, 0.4, 0.6, 0.8, 1, 5, 10, 20, 40 µM C60HyFn, respectively), and then frozen. After thawing, motility and velocity parameters, plasma membrane integrity (PMI) and functionality (PMF), DNA damage, Hypo-osmotic swelling (HOS) test, malondialdehyde (MDA), total antioxidant capacity (TAC), glutathione peroxidase (GPx), superoxide dismutase (SOD), catalase glutathione activities and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging were evaluated. In vivo fertility was compared between k-0.6, C-1 and control groups. 60 buffalo were inseminated 24 h after the onset of estrus. The diagnosis of pregnancy was performed rectally at least 60 days after fertilization. Total and progressive motility and velocity parameters were improved by k-0.4, k-0.6, k-0.8, C-0.4, C-0.8, C-1, C-5, and C-10 groups) compared to the other groups. Plasma membranes integrity and PMF were improved by k-0.4, k-0.6, C-0.4, C-0.8, C-1, C-5, and C-10 groups compared to other groups, while in terms of sperm DNA damage K-0.4, K-0.6, K-0.8, C-0.2, C-0.4, C-0.8, C-1, C-5, and C-10 groups showed better results compared to the control group. The evidence also showed that k- 0.4, k-0.6, k-0.8, C-0.4, C-0.8, C-1, C-5, and C-10 groups could improve TAC, and decrease MDA levels. Also, k-0.4, k-0.6, k-0.8, C-0.2, C-0.4, C-0.8, C-1, C-5, and C-10 groups could improve GPx, CAT, and GSH levels, but no significant difference was found regarding SOD compared to the other groups. DPPH scavengers were tested by K-0.6, K-0.8 and C-1, C-5, C-10, C-0.8, C-0.4 and C-0.2 groups and compared to other groups improved. The fertility rate [70% (14/20)] was higher in C-1 than other groups. To conclude that k-CRG and C60HyFn supplementation can increase the quality parameters of cryopreserved buffalo semen after thawing and that 1 M C60HyFn can increase in vivo fertility of buffalo semen.

Dose Dependent Effects of Aqueous Extract of Garcinia cambogia Desr. Against Letrozole Induced Polycystic Ovarian Syndrome in Female Adult Rats With Possible Mechanisms Exploration.

Background: Polycystic ovarian syndrome (PCOS) is an endocrine metabolic disorder of women. Purpose: This study aimed to explore the potential of aqueous extract of Garcinia cambogia Desr. (AEGC) in PCOS. Methodology: The HPLC was used to determine the phytoconstituents present in Garcinia cambogia. Thirty adult female albino rats were divided into 6 groups: Normal control (NC) disease Control (PCOS; letrozole 1 mg/kg), plant extract (AEGC 100, 300, 500 mg/kg) and standard (metformin; 20 mg/kg). Disease was confirmed by vaginal smear cytology. After 10 weeks, animals were euthanized, ovaries dissected for histopathology, blood collected for hormonal and biochemical analysis. Results: HPLC analysis showed the presence of phenolic contents; chlorogenic acid, gallic acid, coumaric acid while flavonoid contents were quercetin, kaempferol, and rutin. After treatment, there was dose dependent reduction of weight, ovarian cysts, improvement of follicle growth. DPPH radical scavenging percentage was 67.89%. Hormonal analysis showed a significant improvement (P < .05) in follicle stimulating hormone (FSH), estrogen, and progesterone while a reduction in testosterone, luteinizing hormone (LH) and insulin level. Antioxidant enzymatic markers were significantly (P < .05) increased. Lipid profile and LFTs were also improved. Conclusions: The study validated the potential of Garcinia cambogia in the management of PCOS.

Functional and Radiologic Results of Posteromedial Limited Surgery in Developmental Dysplasia of the Hip.

PURPOSE OF THE STUDY In treatment algorithm of developmental dysplasia of the hip, posteromedial limited surgery is placed between closed reduction and medial open articular reduction. The aim of the present study was to assess the functional and radiologic results of this method. MATERIAL AND METHODS This retrospective study was performed in 37 Tönnis grade II and III dysplastic hips of 30 patients. The mean age of the patients at operation was 12.4 months. The mean follow-up time was 24.5 months. Posteromedial limited surgery was applied when sufficient stable concentric reduction was not achieved by closed technique. No pre-operative traction was applied. Postoperatively, human position hip spica cast was applied for 3 months. Outcomes were evaluated regarding modified McKay functional results, acetabular index and presences of residual acetabular dysplasia or avascular necrosis. RESULTS Thirty-six hips had satisfactory and one hip had poor functional result. The mean pre-operative acetabular index was 34.5 degrees. It improved to 27.7 and 23.1 degrees at the postoperative 6th month and the last control X-Rays. The change in acetabular index was statistically significant (p<0.05). At the last control, 3 hips had findings of residual acetabular dysplasia and 2 hips had avascular necrosis. CONCLUSIONS Posteromedial limited surgery for developmental dysplasia of the hip is indicated when closed reduction remains insufficient and medial open articular reduction remains unnecessarily invasive. This study, in line with the literature, provides evidences that this method might decrease the incidences of residual acetabular dysplasia and avascular necrosis of the femoral head. Key words: developmental dysplasia of the hip, posteromedial limited surgery, closed reduction, medial open reduction.

WEIGHT LOSS AND BEYOND, ASSESSMENT OF QUALITY OF LIFE AFTER LAPAROSCOPIC SLEEVE GASTRECTOMY USING BAROS IN PATIENTS WITH OBESITY IN TURKEY.

Context: Sleeve gastrectomy is an effective method for management of obesity. The Bariatric Analysis and Reporting Outcome System (BAROS) is a comprehensive and standard system for the assessment of outcomes of weight loss surgery. It is consisted of weight loss, changes in obesity-related comorbidities and quality of life measurements. We investigated results of the sleeve gastrectomy based on the BAROS. Material and Methods: Outcomes of laparoscopic sleeve gastrectomy surgery was studied in 45 patients with obesity (11 male, 34 female), after 45 months in Turkey. Results: Total weight loss was 26.4±0.1% of body weight at 45 months. Weight regain was seen in 97.8% of the patients with an average 14.5 kg and 13.7% body mass index points. The surgery caused 76% decrease in incidence of obstructive sleep apnea, 73% decrease in type 2 diabetes, 63% decrease in hyperlipidemia and 62% decrease in hypertension. Significant improvement is observed in all quality-of-life parameters. The final score of the BAROS was 4.23±1.02. Conclusion: Based on BAROS, sleeve gastrectomy provides significant improvements in weight loss, incidence of medical comorbidities and quality of life after surgery. Future studies should address prevention of weight regain after the surgery.

Evaluation of mean gray values of a cat with chronic renal failure: case report / [Avaliação dos valores médios de cinza em um gato com insuficiência renal crônica: relato de caso]

In this case, a 12-year-old female domestic cat with chronic renal failure (CRF), which had lived longer than the mean survival time for cats with that condition, was monitored to evaluate the effects of treatment and mean gray value (MGV) changes. The cat has lived for nearly four years since the diagnosis. Probiotics have been used as an additional, classical supportive therapy since the beginning of treatment. The temporal changes in renal MGV were statistically evaluated in the last year of the four-year period. The cat had a comfortable existence and good body condition all her life and probiotic therapy may have had a positive influence post-CRF diagnosis. Ultrasonography (US) examination is a commonly used tool for monitoring the CRF situation, but it is not particularly sensitive. Therefore, MGV may be more useful for the quantitative evaluation of the extent of renal failure. Also, to the best of our knowledge, this is the first report for a long-term clinical evaluation of MGV in a cat with CRF. The aim of this case report was the evaluation of the relationship between MGV and clinical and biochemical changes in a cat with chronic renal failure.(AU)

No presente caso, uma gata doméstica de 12 anos com insuficiência renal crônica (IRC), que viveu mais do que o tempo médio de sobrevivência para gatos nessa condição, foi monitorada para avaliar os efeitos do tratamento e as alterações do valor cinza médio (MGV). A gata viveu quase quatro anos desde o diagnóstico. Os probióticos têm sido usados como uma terapia de suporte clássica adicional desde o início do tratamento. As alterações temporais do MGV renal foram avaliadas estatisticamente no último ano do período de quatro anos. A gata teve uma existência confortável e boas condições corporais durante toda a vida e a terapia com probióticos pode ter tido uma influência positiva após o diagnóstico de IRC. O exame de ultrassonografia (US) é uma ferramenta comumente usada para monitorar a situação da IRC, mas não é particularmente sensível. Portanto, o MGV pode ser mais útil para a avaliação quantitativa da extensão da insuficiência renal. Além disso, até onde se sabe, este é o primeiro relatório de uma avaliação clínica de longo prazo de MGV em um gato com IRC. O objetivo deste relato de caso foi avaliar a relação entre o MGV e as alterações clínicas e bioquímicas em um gato com insuficiência renal crônica.(AU)

The effect of blue thermal treatment on endodontic instruments and apical debris extrusion during retreatment procedures.

AIM: To determine the effect of blue thermal treatment on Reciproc (VDW, Munich, Germany) endodontic instruments and the amount of apically extruded debris during retreatment procedures. METHODOLOGY: Thirty extracted mandibular molar teeth having mesial roots with a degree of curvature less than 20° and having an initial apical size equivalent to a size 10 K-file were selected. The mesial roots of the teeth were removed from the cementoenamel junction to obtain a 15-mm root length. The mesiobuccal canals were prepared to size F2 using the ProTaper Universal system (Dentsply Sirona, Ballaigues, Switzerland), filled with gutta-percha and 2Seal (VDW) using the lateral compaction technique and then randomly divided into two groups (n = 15). The root fillings were removed with one of the following instruments using a crown-down preparation technique: M-Wire Reciproc or Reciproc Blue (both VDW). Apically extruded debris was collected in pre-weighed Eppendorf tubes. The Eppendorf tubes were then stored in an incubator at 70 °C for five days to evaporate the distilled water. The data were analysed using the Mann-Whitney U test (P = 0.05). RESULTS: Reciproc Blue (1.42 ± 0.4491 mg) extruded significantly less debris apically than M-Wire Reciproc (2.56 ± 1.0232 mg) (P < 0.05). CONCLUSIONS: Blue thermal treatment of Reciproc instruments was associated with less debris extrusion during retreatment procedures.

Assessment of successful pregnancy using granular oocytes in ICSI treatments.

SummaryDifferent parameters affect the success of assisted reproduction technology (ART) treatments. One of the advantages of using intracytoplasmic sperm injection (ICSI) is that it also enables the assessment of the oocyte morphology. To date there has not been a clear conclusion on aberrant oocyte morphology and its consequences on the success of ART treatments. Therefore, in this study, we aimed to investigate the fertilization, embryo development and pregnancy rates in patients who have oocytes with granular cytoplasm. Additionally, we investigated if there were more aneuploid embryos obtained from abnormal cytoplasmic morphology. In total, 5704 oocytes were collected and, of these, 4036 were metaphase II (MII) oocytes. The morphology of these oocytes was assessed following denudation and 970 oocytes were observed to have granular cytoplasm. There was no difference in the fertilization rates between the oocytes with normal cytoplasm (89%) and oocytes with granular cytoplasm (72%). Cleavage of embryos and the number of embryos that reached the blastocyst stage were also similar in these two groups. The aneuploidy rates between the two groups were also similar. However, clinical pregnancies were significantly lower in embryos obtained from oocytes with granular cytoplasm (37.5% vs 70%, P<0.05). Therefore, the morphology of the oocyte is as important as morphology of the sperm. Even though normal fertilization and cleavage were achieved from oocytes with granular cytoplasm, their implantation potential was significantly compromised.

Cabergoline treatment in prolactinoma: Amelioration in obstructive and central sleep apneas.

A 44-year-old male patient was admitted to the otolaryngology department with a history of progressive snoring, excessive daytime sleepiness, and reduced libido for the last 6 months. Polysomnography demonstrated the presence of moderate obstructive sleep apnea (OSA) with an apnea-hypopnea index (AHI) of 24.6 events/h, consisting of 77 obstructive and 59 central apneas. The marked number of central apneas in the sleep study and urologic complaints prompted the performance of brain magnetic resonance imaging (MRI), which indicated a pituitary macroadenoma (prolactinoma). Three months after treatment with cabergoline, a control MRI showed a significant reduction in the size of the macroadenoma. The AHI was also significantly decreased (to 11.6 events/h), as were the numbers of obstructive and central apneas. The patient's complaints regarding libido were also regressed. During this treatment period, CPAP therapy has not been tolerated by the patient. Cabergoline treatment reduced the severity of both obstructive and central sleep apneas in this patient.

Common coeliacomesenteric trunk: a computed tomography radiological study.

BACKGROUND: There is an increasing trend for administration of invasive radiological interventions, laparoscopic surgery, and transplantation procedures in recent years, and determining the vascular variations prior to these procedures is crucially important. Coeliacomesenteric trunk (CMT) is among these variations. This study aimed to retrospectively evaluate this rare anomaly by computed tomography (CT). MATERIALS AND METHODS: A total of 1000 CT angiography images were analysed retrospectively, and the patients with mesenteric and coeliac arteries arising from the abdominal aorta with a single root were identified. The level that CMT arose, and its branching patterns were determined individually for all patients. RESULTS: Ten patients (6 males and 4 females) with a mean age of 50.2 years (17-87 years) had CMT in CT images. CONCLUSIONS: The knowledge of variations in the CMT prior to vascular or laparoscopic interventions will contribute to early intervention in case of a complication, or to avoid from a potential damage.

Cyclic fatigue resistance of new reciprocating glide path files in 45- and 60-degree curved canals.

AIM: To compare the cyclic fatigue resistance of R-PILOT and WaveOne Gold Glider files in curved artificial canals. METHODOLOGY: A total of 60 new R-PILOT and WaveOne Gold Glider files were tested in artificial canals with 45° and 60° angles of curvature. Fifteen new files of each brand were tested in both canals. Cyclic fatigue resistance was determined by recording the time to file fracture in the artificial canals. The length of each fractured fragment was also recorded. An independent sample t-test was used to analyse the data. RESULTS: In the canal with a 45° angle of curvature, no significant differences were observed between the R-PILOT and WaveOne Gold Glider files (P > 0.05). In the canal with a 60° angle of curvature, WaveOne Gold Glider files had greater cyclic fatigue resistance than R-PILOT files (P < 0.05). There was no difference between the files in terms of the lengths of fractured fragments in canals with 45° and 60° angles of curvature (P > 0.05). CONCLUSIONS: WaveOne Gold Glider files exhibited greater cyclic fatigue resistance than R-PILOT files in artificial canals with a 60° angle of curvature.

The force required to fracture endodontically roots restored with various materials as intra-orifice barriers.

OBJECTIVE: To evaluate the effect of various materials as intra-orifice barriers on the force required fracture roots. MATERIALS AND METHODS: One hundred-thirty five mandibular premolars were decoronated and prepared up to size #40. The root canals were filled and randomly divided into two control and seven experimental groups (n = 15), as follows: Positive control group (the intra-orifice barrier cavity was not prepared), negative control group (the intra-orifice barrier cavity was prepared, but not filled), filling using glass ionomer cement, nano-hybrid composite resin, short fiber-reinforced composite, bulk-fill flowable composite, MTA Angelus, Micro Mega MTA or Biodentine. A fracture strength test was performed, and the data were analyzed using one-way ANOVA and Tukey's post hoc tests. RESULTS: Nano-hybrid composite, short fiber-reinforced composite, bulk-fill flow able composite, and glass ionomer cement increased the force required fracture the roots compared to the positive and negative control groups (P < 0.05). While MTA groups did not increase the force required fracture the roots compared to the control groups, Biodentine increased significantly. CONCLUSIONS: Within the limitations of the present study, the use of nano-hybrid composite, short fiber-reinforced composite, bulk-fill flowable composite, and glass ionomer cement as an intra-orifice barrier may be useful in reinforcing roots. MTA placement (MTA Angelus or Micro Mega MTA) did not significantly increase the fracture resistance of endodontically treated roots compared to the control groups, however Biodentine did.

Effects of thiocolchicoside, a commonly used myorelaxant, on the acoustic reflex.

OBJECTIVE: To determine whether thiocolchicoside, a commonly used myorelaxant, may impair the acoustic reflex. METHODS: Forty-two patients scheduled to receive thiocolchicoside treatment for different reasons were enrolled in the study. Acoustic reflex thresholds at 500, 1000, 2000 and 4000 Hz were determined and analysed statistically pre-treatment and on the 5th day of treatment. RESULTS: Increases were observed in the mean acoustic reflex thresholds on the 5th day of treatment compared to pre-treatment, at all frequencies, except right contralateral thresholds at 500 and 2000 Hz. These increases were statistically significant for right ipsilateral thresholds at 2000 and 4000 Hz, left ipsilateral thresholds at 500, 1000, 2000 and 4000 Hz, and left contralateral thresholds at 2000 and 4000 Hz (p ≤ 0.05), but not at other frequencies (p > 0.05). CONCLUSION: Muscle relaxant drugs, especially those affecting the central nervous system, may weaken the stapedial muscle so that the ability of noise to cause acoustic trauma may become evident. For this reason, physicians should advise their patients to avoid loud noises when muscle relaxant therapy is prescribed.

New inflammatory parameters in laryngopharyngeal reflux.

OBJECTIVES: To investigate new inflammatory markers in patients with laryngopharyngeal reflux and determine whether these inflammatory parameters change in response to laryngopharyngeal reflux treatment. METHODS: Complete blood count was evaluated to obtain platelet count and mean platelet volume and calculate neutrophil-to-lymphocyte ratio and platelet-to-lymphocyte ratio. Laryngopharyngeal reflux patients underwent three-month lansoprazole treatment. RESULTS: The study included 45 laryngopharyngeal reflux patients (9 men (20 per cent); mean age, 37.4 ± 11.6 years) and 35 healthy age- and sex-matched controls (7 men (20 per cent); mean age, 38.6 ± 8.9 years). The study group had significantly higher platelet-to-lymphocyte ratios and lower mean platelet volumes than the control group (p = 0.004 and p = 0.047, respectively). There was a significant correlation between platelet-to-lymphocyte ratios and initial inflammatory symptoms (reflux symptom index, p = 0.025; reflux finding score, p = 0.013). There was also a significant correlation between mean platelet volume increase and symptom resolution in the first and third months of treatment (p = 0.04 and p = 0.03, respectively). CONCLUSION: Platelet-to-lymphocyte ratio, a new inflammatory marker of chronic inflammation, was significantly higher in laryngopharyngeal reflux patients. Moreover, these patients had significantly lower mean platelet volume values, which increased with post-treatment symptom improvement.

Effects of prenatal diclofenac sodium exposure on newborn testis: a histomorphometric study.

Diclofenac sodium (DS) is used primarily to treat fever and to alleviate pain and inflammation. We investigated the effects of DS exposure during gestation on the testes of rat pups to investigate the safety of its use during the prenatal period. Pregnant rats were separated into control, saline, low dose, medium dose and high dose groups. DS was given between weeks 15 and 21 of gestation. Total numbers of spermatogonia and Sertoli cells were counted in the testes of 7-day-old male rats using the physical disector method. By the end of the study, the total number of Sertoli cells was decreased significantly in a dose dependent manner in the medium and high dose groups compared to controls. No significant differences were found in the total number of spermatogonia in the control, saline and low dose DS groups. Medium and high dose DS administration reduced the total number of spermatogonia compared to other groups. We suggest that prenatal administration of DS can cause deleterious effects on the testis development, especially in high doses.

Influence of different surface treatments on push-out bond strengths of fiber-reinforced posts luted with dual-cure resin cement.

OBJECTIVES: The objective was to evaluate whether fiber postsurface conditioning with air abrasion or erbium:yttrium-aluminum-garnet (Er:YAG) laser would influence the bond strength of dual-cure resin cement to the fiber-reinforced (FRC) posts. MATERIALS AND METHODS: Twenty-one FRC posts were divided into three groups according to surface treatment methods as follows: An untreated control group air abrasion with Al2O3group, and Er:YAG laser treated group with 150 mJ parameter. Fiber posts were then built up to dual-cure resin cement. Eighteen specimens were set and sectioned perpendicularly along the long axis of the post using a saw. Two disks (thickness of 2 mm) were obtained from each specimen (n = 12). Remaining three posts were stored for scanning electron microscopic evaluation. Push out test was performed on the each specimen and the values were recorded as MPa. The data were analyzed using one-way analysis of variance and Tukey post-hoc tests (P < 0.05). RESULTS: The bond strength values for the groups were as follows: Control (15, 28 MPa), air abrasion group (19, 73 MPa), and Er:YAG group (17, 84 MPa). Air abrasion affected the bond strength significantly (P < 0.05). CONCLUSION: Air abrasion attained higher bond strengths when FRC posts were luted to dual-cure resin cement. Additional studies should be designed with different types and parameters of laser devices to understand the effect of these devices on bond strength.

Incidence of dentinal cracks after root canal preparation with ProTaper Gold, Profile Vortex, F360, Reciproc and ProTaper Universal instruments.

AIM: To assess the effect of root canal preparation using ProTaper Gold, Profile Vortex, F360, Reciproc and ProTaper Universal instruments on dentinal crack formation. METHODOLOGY: Ninety mandibular central incisor teeth with mature apices and straight canals (<5° ) were selected and stored in distilled water. Fifteen teeth were left unprepared (control group) and the remaining 75 teeth were assigned to the five root canal shaping groups (n = 15): ProTaper Gold, ProFile Vortex, F360, Reciproc and ProTaper Universal. All the roots were sectioned perpendicular to the long axis at 3, 6 and 9 mm from the apex with a low-speed saw under water cooling. The slices were then viewed through a stereomicroscope at 25×  magnification. The presence of dentinal cracks was determined by photographing all samples using a digital camera. RESULTS: All the experimental groups, except F360, produced significantly more cracks than the control group (P < 0.05). No significant difference was observed amongst the groups at the 6 and 9 mm levels (P > 0.05). The ProTaper Universal group produced significantly more cracks than the control, ProTaper Gold, ProFile Vortex, F360 and Reciproc groups at the apical section (3 mm) (P < 0.05). CONCLUSION: All the systems that were tested produced dentinal cracks. There was no significant difference between the control and F360 groups in terms of dentinal crack formation.