Microleakage along Glassix glass fibre posts cemented with three different materials assessed using a fluid transport system.

AIM: To evaluate the microleakage along Glassix fibre posts cemented with three different materials. METHODOLOGY: The root canals of maxillary central incisor teeth were filled and restored with Glassix posts (Harald Nordin sa, Chailly/Montreux, Switzerland) cemented with either a zinc-phosphate Harvard cement (Richter & Hoffmann, Harvard Dental GmbH, Berlin, Germany), Fuji PLUS cement (GC Corporation, Tokyo, Japan) or Variolink II cement (Vivadent, Schaan, Lichtenstein) in three groups of 15 canals each. Twenty unrestored canals served as a control group, 10 filled with gutta-percha and sealer (negative control group), the remaining 10 with gutta-percha only (positive control group). Coronal microleakage was evaluated using a fluid transport system. The movement of an air bubble in a capillary glass tube connected to the apex of the experimental root section was measured over 5-min periods. Measurements were performed four times for each specimen and the mean values recorded. ANOVA and Duncan's test were performed. RESULTS: The positive control group had the highest values of microleakage. Amongst experimental groups, the highest values of microleakage occurred in the group with the posts cemented with Harvard cement, followed by Fuji PLUS and Variolink II cements. Groups with Fuji PLUS, Variolink II and the negative control group had significantly (P < 0.00001) less microleakage compared with the Harvard cement group and the positive control group. CONCLUSION: Canals with Glassix posts cemented with Variolink II and Fuji PLUS cement had the least leakage when assessed using a fluid transport system.

Removal of gutta-percha from root canals using an Nd:YAG laser.

AIM: To examine the use of an Nd:YAG laser in removing gutta-percha fillings from root canals when used in conjunction with eucalyptol, dimethylformamide (DMF) or no solvent. METHODOLOGY: Root-canal fillings (sealer and gutta-percha) were removed with laser irradiation of 20 Hz/1.5 W from 30 roots randomly divided in three groups. In group 1, the solvent was eucalyptol; in group 2, the solvent was DMF; and in group 3, no solvent was used. Laser irradiation was performed until the temperature measured on the root surface increased by 4 degrees C over room temperature. The treatment was deemed complete when the apical foramen was reached with the optical fibre and a reamer. The samples were split longitudinally, and the area of remaining gutta-percha on the root-canal walls was determined with the aid of a computer program. The total number of laser pulses to achieve length and the highest temperature recorded was determined for each tooth. The results were statistically analysed using Student's t-test (P < 0.05) for independent samples. RESULTS: The average temperature increase in group 1 was 9.17 +/- 0.56 degrees C; in group 2, 9.56 +/- 0.28 degrees C; and in group 3, 8.29 +/- 0.41 degrees C. The shortest time to achieve length was in group 3 (6.4 +/- 0.49 min), then in group 1 (6.7 +/- 0.85 min) and group 2 (7.05 +/- 0.79 min). The area of remaining gutta-percha was the largest in group 2 (6.13 +/- 5.76%), whilst the smallest was for group 3 (4.69 +/- 4.03%), but the difference was not statistically significant. The number of pulses was not statistically significant between the groups. CONCLUSIONS: Use of an Nd:YAG laser alone is capable of softening gutta-percha. The addition of solvents did not improve the retreatment, either in terms of the time required for the procedure or in terms of the area of remaining gutta-percha on root-canal walls.

Examination of cytotoxicity and mutagenicity of AH26 and AH Plus sealers.

AIM: To study in vitro the cytotoxic and mutagenic effects of AH26 and AH Plus. METHODOLOGY: Cytotoxic effects on Chinese hamster V79 cells were determined by counting viable cells following incubation with eluations of AH26 and AH Plus. In one set of experiments, the materials were mixed, set for 1 h and then eluted with dimethyl sulphoxide (DMSO) for 1 h, 24 h and 7 days. In the other set, AH26 and AH Plus were mixed and set for 1 h, 24 h and 7 days in physiological saline then crushed and eluted in DMSO for 24 h. The cytotoxic effects of these eluates were evaluated. Three concentrations were chosen to examine the mutagenic effects of AH26 and AH Plus: 5.57, 16.7 and 55.7 microg mL(-1). The structural chromosomal aberration analysis and micronucleus test were performed on human lymphocytes according to standard procedures. RESULTS: Dose-response curves of cell survival were obtained. Both materials were shown to be cytotoxic in doses larger than 55.7 microg mL(-1), except for AH26, after 7 days setting time. AH Plus was also shown to be toxic in concentrations of 16.7 microg mL(-1), except after 7 days setting time. Neither AH26 nor AH Plus induced a significant increase of chromosomal aberrations or micronuclei induction at any setting time or concentration. CONCLUSION: There was no mutagenicity found for AH26 and AH Plus on human lymphocytes in highly controlled conditions in vitro.

Salivary levels of vascular endothelial growth factor (VEGF) in recurrent aphthous ulceration.

BACKGROUND: Vascular endothelial growth factor (VEGF) is a multifunctional angiogenic cytokine involved in angiogenesis and wound healing. Its presence in recurrent aphthous ulceration has not been reported to date. The aim of this study was to investigate the association of salivary levels of VEGF with various stages of recurrent aphthous ulceration (RAU). METHODS: VEGF levels were determined in a group of 27 age and sex-matched healthy controls and in 30 patients with minor and major RAU grouped into the three stages: (I) early active stage, (II) active stage, and (III) remission period. VEGF levels (pg/ml; mean +/- SD) in unstimulated whole saliva were determined by enzyme immunoassay. RESULTS: Patients with major RAU - stages I and II - had decreased VEGF values (765 +/- 458 and 341 +/- 109, respectively) when compared both to healthy controls (1652 +/- 567; P < 0.01) and to stage III major RAU (1524 +/- 784; P < 0.005). CONCLUSION: Salivary VEGF levels seemed to be associated with ulcer development in major RAU, showing stage-dependent alterations during the course of this disorder.

Nicotinamide adenine dinucleotide phosphate-diaphorase (NADPH-d) histochemistry detecting NOS in healthy and chronically inflamed pulp.

The aim of this study was to examine the expression of nicotinamide adenine dinucleotide phosphate-diaphorase (NADPH-d) activity in human dental pulps and determine whether there are changes of the activity in chronically inflamed pulp tissue. Nineteen pulps with clinical diagnosis of chronic pulpitis were collected during endodontic treatment. The healthy controls were obtained from teeth extracted for orthodontic therapy. The clinical diagnosis was confirmed by histological analysis. Healthy pulps showed stratified odontoblasts in peripheral parts, while in central area there was normal connective tissue. Chronically inflamed pulps showed less expressed stratification of odontoblasts and infiltration of lymphocytes, polymorphonuclear leukocytes, plasma cells and mastocytes. NADPH-d granular reactivity was assessed semi quantitatively under the light microscope by a single observer and scored on an intensity scale from negative reaction to very strong reaction. In healthy human pulps, NADPH-d activity was strong to very strong in odontoblastic layer. Endothelial cells and Schwann cells showed strong NADPH-d reactivity, while the other parts of central area were weakly positive. Similar distribution of reactivity was expressed also in chronically inflamed pulp; moderate to strong reaction was observed in stromal area as result of positive reaction in inflammatory cells and endothelial cells of abundant newly formed capillaries.

The value of cell proliferation and angiogenesis in the prognostic assessment of ovarian granulosa cell tumors.

OBJECTIVES: Most cases of granulosa cell tumors (GCT) of the ovary are characterized by a relatively good outcome. However, some tumors behave aggressively and some tend to recur many years after the initial diagnosis. Tumor growth depends on cell proliferation and angiogenesis. Thus, proliferative indices and microvessel density were studied to determine possible valuable methods to assess the GCT patient's outcome. METHODS AND STUDY DESIGN: Paraffin-embedded tissue blocks were available for 60 patients with primary GCT and were investigated by immunostaining with monoclonal antibodies against PCNA, Ki-67 and factor VIII-related antigen. The follow-up was available for 51 patients and ranged from 25 to 206 months. A clinical follow-up distribution of patients was made: 8 patients with recurrence (group I); 6 patients who lived with no evidence of recurrence for 100 months or more (group II), and 37 patients alive with no evidence of recurrence in the follow-up period of less than 100 months (group III). RESULTS: There was a statistical correlation between PCNA and Ki-67 proliferative indices. A significant increase (P <0.05) of mean PCNA and Ki-67 proliferative indices and mean tumor size was seen in patients of Group I compared to those of Group II. The mean PCNA proliferative index positively correlated with the mean Ki-67 proliferative index for Groups I and II. Mean microvessel density showed a positive correlation with mean PCNA and Ki-67 proliferative indices and with mean tumor size for Group I, whereas it was negatively correlated with PCNA proliferative index and tumor size for Group II. A positive correlation was found between mean mitotic count and both proliferative indices only for Group II. The following features were indicative of a relatively poor prognosis: GCT measuring >9 cm in diameter, PCNA >4.0%, Ki-67 >1.2%, and diffuse, insular and sarcomatoid histologic patterns. CONCLUSIONS: The findings support the importance of proliferative factors, tumor size and histologic patterns as possible prognostic indicators for estimating the biologic behavior of patients with GCT. Unfortunately, angiogenesis did not seem to be a useful determinant parameter of a possible aggressive behavior. However, a longer follow-up period with larger series may be required to assess the value of the parameters in prediction of patient survival.

Improved national Croatian diagnostic and therapeutic guidelines for premalignant lesions of the uterine cervix with some cost-benefit aspects.

The national Croatian improved diagnostic and therapeutic guidelines for premalignant lesions of the uterine cervix are presented: for atypical squamous cells of undetermined significance (ASCUS), for cervical intraepithelial neoplasia (CIN I, CIN II CIN III) and for microcarcinoma (FIGO grade Ia1). Separately are presented the guidelines for abnormal glandular epithelium: atypical glandular cells of undetermined significance (AGCUS) and cervical glandular intraepithelial neoplasia (CGIN). The guidelines are created according to the guidelines of the FIGO. Improved diagnostic and therapeutic guidelines was presented and accepted at the Symposium of the Croatian Society for Colposcopy and Cervical Pathology and of the Croatian Society of Gynecologists and Obstetricians of the Croatian Medical Association, held on November 25th 2000. There are presented the chief differences and the some cost-benefit aspects between the guidelines before and the new one.

DNA ploidy analysis and cell proliferation in congenital sacrococcygeal teratomas.

BACKGROUND: Congenital sacrococcygeal teratoma is the most common germ cell tumor in infants and children. It usually is diagnosed at birth, is benign, and consists of fully differentiated mature tissues. Congenital sacrococcygeal teratomas (SCTs) also may contain immature tissues, most commonly of neural origin. The proportion of malignant teratomas increases with advancing age, but the relation between mature and immature SCTs is not well understood. Thus, it is very important to determine proliferative activity, DNA ploidy, and DNA index to predict biologic behavior of these tumors. METHODS: DNA ploidy and cell proliferation were analyzed by flow cytometry, and the expression of proliferating cell nuclear antigen (PCNA) and Ki-67 were analyzed immunohistochemically on paraffin embedded tissue. RESULTS: All the tumors that were surgically treated within 3 months after birth, including immature teratoma, were diploid. Strongly positive PCNA immunostaining was found in both immature teratomas, and weakly positive PCNA was found in nine cases. Weak positivity for Ki-67 was observed in 2 cases, and moderate positivity was observed in 6 cases including immature teratomas. CONCLUSION: The value of flow cytometry in the prediction of biologic behavior of congenital SCT should be analyzed further. Our results suggest that Ki-67 and especially PCNA may reflect the proliferative activity of these tumors.

The mutagenic potential of AH+ and AH26 by Salmonella/microsome assay.

The aim of this study was to examine the mutagenic potential of canal sealers AH+ and AH26 by Salmonella/microsome assay. The materials were tested immediately after mixing, 1 hr and 1 month later, respectively. The dimethyl sulfoxide extracts of sealers in amounts of 3.0, 1.5, and 0.75 microliters/plate were used. The plated bacterial strains of Salmonella were TA 98 and TA 100. The results showed that AH+ is mutagenic toward strain TA 100 1 hr after mixing. One month after mixing, mutagenic activity was expressed only in TA 98. Paste A showed strong mutagenicity toward TA 100. AH26 was more mutagenic to the TA 100 immediately after mixing, 1 hr later, and 1 month after it was polymerized. Also it was mutagenic toward TA 98 in the polymerized condition. Further examinations should be conducted to establish a definitive conclusion about mutagenic potential for these two endodontic materials.

Leakage of five root canal sealers.

AIM: The aim of this study was to examine the apical sealing ability of five root canal sealers using a fluid transport model. METHODOLOGY: A comparison of root canal scalers AH26, AH Plus, Diaket, Apexit, and Ketac-Endo were tested on 60 single-rooted teeth. The coronal part of each tooth was removed at the amelo-cemento junction, and also 3 mm of the root tip. Root canals were instrumented using the 'step-back' technique with Gates Glidden drills and irrigated with 2.5% NaOCl. The specimens were divided into five groups of 10 samples each and filled with test materials and gutta-percha points by the cold lateral condensation technique. Ten teeth were used as a control group, out of which five served as negative and five as positive controls. The leakage was measured by the movement of an air bubble in a capillary glass tube connected to the experimental root section. RESULTS: The differences in leakage amongst Ketac-Endo (0.318 microL: SD 0.084), AH26 (0.319 microL; SD 0.075), AH Plus (0.330L; SD 0.085) Apexit (0.360 microL; SD 0.127) and Diaket (0.387 microL; SD 0.140) were not statistically significant (P > 0.05). CONCLUSIONS: Under the conditions of this study, all five sealers produced a satisfactory seal.

Computer-based teaching of pathology at the Zagreb University School of Medicine.

AIM: To review the experience gained in transferring USA computer-based teaching system of medical school pathology to Croatia. METHODS: Computer-based teaching program of pathology developed at the University of Kansas School of Medicine, Kansas City, Kansas, USA, was transferred to the University of Zagreb School of Medicine, Zagreb, Croatia. The experimental group of 49 students was enrolled into this computer-based program. Their performance was compared with that of 195 classmates enrolled in the standard course. Objective (performance on the examinations) and subjective data (students' interviews and written evaluations of the course) were analyzed. RESULTS: The computer program was operational 5 months from the inception of the transfer. It was well received by the students, even though many initially complained that it required more effort and a continuous commitment. The major problems concerned scheduling, reflecting various requirements i mposed on students by other departments teaching in parallel with the Pathology course. Objective data gathered so far indicate that the students enrolled in the computer-based program took the first midterm examination at a significantly higher rate than the rest of the class (p<0.001), and passed the examination with significantly better grades (p<0.001). CONCLUSION: Computer-based teaching programs can be readily transferred to other countries. Full implementation of the program, however, may require significant changes in the existing curriculum in the medical school to which such a program has been transferred or considerable modifications in the program adopted for transfer. It appears that the students enrolled in the computer-based program perform better than students in the standard pathology course.

Morphology of gonads in pure XY gonadal dysgenesis.

The authors gathered 20 patients having Swyer's syndrome and performed a bilateral gonadectomy and carried out a pathohistologic evaluation of the streak gonads. A more frequent occurrence of streak gonad tumors was found together with the possibility of tracing the merge gonadoblastoma into dysgerminoma (the youngest patient was 15 years old). In 95% of the streak gonads checked an ovary-like stroma was found. In 11 of the patients (55%) one of the above mentioned tumors was found. A frequent finding was the presence of Leydig-type cells, calcifications and the remains of Wolffian canals. In three streak gonads, the corpora albicans-like formations were found.

Erythema nodosum of dental origin.

This paper describes the case of a patient who had erythema nodosum which disappeared following teeth extraction.

Effects of tamoxifen on steroid hormone receptors and hormone concentration and the results of DNA analysis by flow cytometry in endometrial carcinoma.

OBJECTIVES: Tamoxifen is a nonsteroidal triphenylethylene derivate with a predominant antiestrogen activity, used in the endocrine treatment of breast and endometrial cancer. It is not known which endometrial carcinomas will respond favorably to tamoxifen and which ones will not. The aim of this study was to find out whether tamoxifen has an effect on hormone steroid receptors, hormone concentration, DNA content, and proliferative activity in endometrial cancer and to correlate the tamoxifen-induced changes with pathologic parameters such as clinical stage, tumor differentiation, depth of invasion, and histologic type. METHODS: Thirty postmenopausal women with endometrial carcinoma were treated with 30 mg of tamoxifen daily for 7-10 days after curettage. Steroid hormone receptors (estrogen and progesterone receptors), levels of follicle-stimulating hormone, luteinizing hormone, prolactin, estradiol, progesterone, testosterone, dehydroepiandrosterone sulfate, sex hormone binding globulin, and DNA ploidy and proliferative activity were determined before and after therapy. The patients were also divided into favorable and unfavorable prognosis groups according to classical histological parameters. The patients in the favorable group consisted of patients with stage I disease, well and moderately differentiated tumors, favorable histologic type, and a depth of myometrial invasion of less than (1/3). The patients with only one of the unfavorable parameters (clinical stage II or III, poorly differentiated tumors, unfavorable histologic types, and deeper invasion of myometrium) were included in the unfavorable prognosis group. RESULTS: After the treatment, there was a net increase in the progesterone receptors and sex hormone binding globulin and a significant decrease in the estrogen receptors. The increase in progesterone receptors and decrease in estrogen receptors occurred in the patient group with favorable prognosis regarding histologic type, degree of differentiation, and clinical stage, but also in the unfavorable prognosis group regarding the depth of myometrial invasion. Statistically significant decrease in the follicle-stimulating hormone concentration was observed in the groups with favorable prognosis regarding histologic type, depth of myometrial invasion, and grade of differentiation. Concentration of sex hormone binding globulin was significantly increased in groups with favorable prognosis if histologic type and grade of differentiation were taken into account. On the other hand, there was a significant decrease in the concentration of luteinizing hormone in the group with unfavorable histologic type and also a decrease in progesterone concentration in patients with unfavorable prognosis regarding the grade of differentiation. There was no statistical significance either in the concentrations of other hormones measured or in the DNA analysis by flow cytometry. CONCLUSIONS: Our results revealed that tamoxifen can increase progesterone receptors and decrease estrogen receptors in endometrial cancer. The effect was most pronounced in tumors with favorable clinicopathologic parameters. We conclude that tamoxifen therapy can induce progesterone receptor synthesis even in tumors with low initial progesterone receptor levels, making such tumors potentially responsive to additional hormonal therapy with progesterone.

[Tumoral angiogenesis--hot topic in science again]. / Tumorska angiogeneza--ponovno vruca znanstvena tema.

Angiogenesis is the formation of new capillary blood vessels. It has a very important role not only in physiological conditions but in the process of malignant tumors growth. Weak muscular layer, chaotical branching and irregular shape, are the characteristics of newly formed tumorous vessels. The number and arrangement of blood vessels differ between benign and malignant tumors. Latest data suggesting that drugs inhibiting angiogenesis can stop growth of malignant tumors made the research on tumorous angiogenesis a hot topic recently. Although reliable in differentiating benign from malignant tumors, two-dimensional ultrasound with color and pulsed Doppler, can not make spatial image of vascular architecture. Three-dimensional (3D) ultrasound with color Doppler allows the investigator to have a three-dimensional architectural picture of tumorous vascular network, and according to the findings it is possible to detect malignant tumors even in doubtful cases.

Congenital anomalies of the central nervous system at autopsy in Croatia in the period before and after the Chernobyl accident.

In this study, we analyzed the frequency, type and sex distribution of congenital anomalies of the central nervous system (CNS) at autopsy in the period prior to and after the Chernobyl accident in northwest Croatia, one of the areas with the highest exposure to nuclear contamination from Chernobyl. All autopsies in both periods were performed by the same technique, i.e. dissection of the trunk and head, and inspection of the extremities. There were 53 infants with congenital anomalies of the CNS in the period prior to, and 99 in the period after the Chernobyl accident. Our results showed a statistically significant increase in the incidence of CNS anomalies in general (chi 2 = 4,719, p < 0.05, D. F. = 1) and of neural tube defects (chi 2 = 5.380, p < 0.05, D. F. = 1) in the period after the Chernobyl accident. Differences in the incidence of various CNS anomalies, in all types of anomalies, and in sex distribution were not statistically significant. Studies of the association between the Chernobyl accident and congenital anomalies showed no clear changes in the prevalence of anomalies at birth which might have been associated with the accident. This study provided some additional data on the frequency of CNS anomalies in the period after the Chernobyl accident in one of the areas with the highest exposure to the nuclear contamination from Chernobyl. We suggest that the frequency of all anomalies, including CNS, in the period after the Chernobyl accident should be carefully monitored.

Some periodontological parameters in patients with oesophagogastric passage insufficiency.

The aim of this study was to examine the state of oral hygiene (OHI), the presence of tooth calculus and the condition of the gingiva on the group of 101 patient with oesophagogastric passage insufficiency. The control was group of 78 examines without clinical signs of oesophagogastric disease. The plaque was visualised by plaque revelator and recorded on each tooth. The calculus and condition of gingiva was determined according to the modified instruction of WHO, 1987. Both parameters were determined for each sextant of upper and lower jaw. The results of the OHI on the patients with oesophagogastric passage insufficiency (0.3, SD 0.126) was statistically different (p < 0.01) in comparison with control group (0.51, SD 0.25). Pathological changes of gingiva were more prominent in patient with insufficiency and that difference was statistically significant (p < 0.05). Calculus was more evident in control group but statistically insignificant (p < 0.1). The data show that insufficiency of oesophagogastric passage can cause pathological changes of gingiva while the lower OHI and less prominent calculus could be explained probably by better oral hygiene of patients because of bad taste in mouths.

Occupational tooth-wear in clothing industry workers.

A research on tooth-wear was done in a clothing factory, focusing on the teeth of the inter-canine sector in 59 workers who had volunteered for the research. The subjects were in the habit of cutting the thread with their teeth instead of using scissors as was prescribed in the production process. In 53 (89.83%) of the subjects, damages of the incisal portion of the tooth were found, whereas in the remaining 6 (10.17%) there were no such changes. No significant difference could be established in the incidence of tooth-wear between the women workers who cut the thread with their teeth constantly and those who only did that occasionally (p > 0.05). Because of the action of pulling a thread across the incisal edge of the incisor, defects--in the form of solitary, oval or multiple cuts (attributed the values 1, 2 and 3)--had been inflicted on the incisal portion of the teeth. Most frequently those were the defects of the enamel (type 2, 1), but in some cases dentin (type 3), also was affected. A somewhat more severe degree of damage was observed from workers biting the purely polyester-made thread (p < 0.05) than from biting the regular sewing type of thread. Education of the workers seems to be the only useful prevention, since we are dealing with only a bad habit. Therefore, the workers should be warned that the seemingly innocent cutting of thread with their teeth could lead to esthetic, functional and restorative problems.

Loop excision of the transformation zone (LETZ) as an outpatient method of management for women with cervical intraepithelial neoplasia: our experience.

Between March 1996 and July 1998, 90 patients were treated with diathermy loop excision (LETZ) for cytologically, colposcopically and histologically verified cervical intraepithelial neoplasias (CIN), at the outpatient clinic. In average, the patients were 30.22 years of age, and 61.1% of them were nulliparas. In 80 surgical samples (88.9%), the exocervical and endocervical margins were histologically free of disease. From the total of 65 patients with CIN III diagnosis, 58 (89.2%) had free margins samples. In the post-operative period the patients had a changed vaginal discharge for 16 days. A slight feeling of pain in the abdomen lasted for 2.5 days on the average, and most patients did not take analgetics. Moderate postoperative hemorrhage from the excision site occurred in 5 (5.5%) patients, and was outpatiently treated with electrocoagulation, with no need for blood replacement. In 65 patients (90.3%), the cytological control results were normal. During the follow-up period, 9 patients became pregnant, which resulted in 6 terminal deliveries so far; 2 pregnant women are about to deliver, and one is in the first trimester of pregnancy. Cerclage cervicis has not been performed on any of the patients. LETZ is a safe and simple procedure which can be done at outpatient clinics, it is relatively easily mastered, it is short, quite bearable for patients if done only under local analgesia, the equipment costs are acceptable, and the treatment can be used both diagnostically and therapeutically, since an adequate surgical sample is obtained for histological assessment. Cytological and colposcopical check ups are imperative in the postoperative period.