Pulpal necrosis with sickle cell anaemia.

AIM: To investigate radiographic manifestations of sickle cell anaemia (SCA) and whether or not a pulpal necrosis may develop without a pathological history. METHODOLOGY: Thirty-six patients with homozygous SCA were evaluated, and a further 36 individuals without SCA were included in the study as a control group. All 72 patients participating in the study ranged between the ages of 16 and 40 years. General and dental histories of the individuals were recorded. Electrical pulp test, percussion and thermal tests were applied to all the teeth having no restorations. Orthopantomograms of all the subjects were taken. Data obtained from questionnaires, sensitivity tests and radiographic examinations were evaluated by chi-square and Fischer's exact test. RESULTS: Fifty-one (6%) of the teeth having no restorations or history of trauma were determined as being nonvital in the SCA group. In 30 (83%) of these patients orofacial and dental pain with no obvious cause was detected and in 24 (67%) of the patients the quality of the bone tissue as examined radiologically had deteriorated. In eight (22%) of the patients cortical thinning and irregularity in the mandible was noted. A statistically significant difference between the SCA and control groups (P < 0.05) was found in terms of pulpal sensitivity and radiological findings. CONCLUSION: SCA is a genetic and systemic disease which may cause pulp necrosis without necessarily having an identifiable aetiology. SCA causes radiographically observable differences in jaw structure especially in the mandible.

Twenty-four-month clinical evaluation of different posterior composite resin materials.

BACKGROUND: In a 24-month clinical trial, the authors compared three brands of light-cured composite resins that were used to restore the posterior teeth of 38 patients. METHODS: A total of 88 Class I and 32 Class II restorations were made using Z100 (3M Dental Products Div.), Clearfil Ray-Posterior (Kuraray Co. Ltd.) and Prisma TPH (Caulk/Dentsply). Quadrant impressions were taken using a polyvinyl siloxane impression material, and stone casts were obtained every six months for indirect evaluations of anatomical form and marginal adaptation. The restorations were evaluated directly by three clinicians using the Ryge criteria. RESULTS: The authors statistically evaluated parameters at each recall period, using a chi 2 test; compared baseline scores with the recall scores, using a McNemar test; and evaluated changes in the parameters, using the Cochran Q test. Color match, cavosurface margin discoloration and secondary caries remained unchanged at the end of the 24-month recall period for all materials (P > or = .05). A total of 11.5 percent of the Z100 restorations and 16.7 percent of the Prisma TPH restorations showed a slight crevice along the margin (P < or = .05). The surface texture was scored as Bravo only for Clearfil Ray-Posterior restorations at the end of the study (P < or = .05). The authors found that the indirect evaluation results were different from the direct evaluations for Z100 and Prisma TPH. CONCLUSIONS: According to these findings, all the materials used are suitable for posterior restorations. The difference between the two evaluation methods can be attributed to the level of sensitivity. CLINICAL IMPLICATIONS: With the improvement in materials, careful case selection and application of the restorative techniques, posterior composites placed under appropriate conditions and monitored routinely can be expected to last 10 years or longer.

The penetration of root canal sealers into dentinal tubules. A scanning electron microscopic study.

The purpose of this study was to evaluate the effect of smear layer on penetration of four root sealers into dentinal tubules. Sixty-four, recently extracted, human maxillary and mandibular incisors were used. Following removal of the crowns, the pulps were extirpated and the root canals instrumented. The teeth were then divided into two groups. The teeth in the control group were irrigated with saline solution and the experimental group treated with EDTA and NaOCl. Each main group was then divided into four sub-groups and the root canals filled with Diaket, N2 Universal, SPAD and Forfenan as recommended by the manufacturers. The teeth were split longitudinally and examined using scanning electron microscopy. A quantitative assessment was made of sealer penetration into the dentinal tubules in the coronal, middle and apical parts of each root canal. It was observed that the smear layer obstructed the penetration of the tubules by the sealers. However, in the experimental group, the penetration into dentinal tubules was better with Diaket, N2 and SPAD, than with Forfenan (P < 0.01). It was concluded that this penetration could be affected by physical and chemical properties of root canal filling materials.

Neural changes in ulcerative and hyperplastic pulpitis: a transmission electron microscopic study.

The purpose of this study was to examine at ultrastructural level the neural changes in human apical pulps of teeth clinically diagnosed as having ulcerative or hyperplastic pulpitis. Seventeen specimens were prepared from six teeth with ulcerative or hyperplastic pulpitis and four specimens from two sound teeth. After routine procedures the specimens were examined under an electron microscope for changes in the structure of myelinated and unmyelinated nerve fibres. Although the teeth used in this study responded positively to vitality test, the results revealed that moderate to severe degenerative changes occurred in the nerve fibres of the apical pulps of the teeth showing these two diseases.

Smear layer removal with different concentrations of EDTA-ethylenediamine mixtures.

The purpose of this study was to observe the effectiveness of EDTA and ethylenediamine mixtures in removing the smear layer from prepared root canal walls following instrumentation. Thirty-five freshly extracted, single-rooted maxillary anterior teeth were used. After the preparation of access cavities and establishing the working length, the apical foramen of each canal was sealed with casting wax. All canals were then sequentially enlarged with K-type files to size 50. The sample was divided into seven groups of five teeth. The teeth in the control group were irrigated with saline solution. The specimens in the other groups were irrigated with 10 and 20 ml of three different EDTA-ethylenediamine mixtures. A scanning electron microscopic evaluation of the canal walls following irrigation showed that the superficial layer was totally removed and the openings of the dentinal tubules were patent. Only at the coronal third of the teeth in group 4 and the apical thirds in groups 2 and 4 was a moderate smear layer observed. The most favorable results were obtained with groups 5, 6, and 7. The results show that the smear layer can be totally removed by using 10 ml of a four-to-three by volume mixture of EDTA and ethylenediamine for irrigation of instrumented root canals.

Sealing ability of cermet ionomer cement as a retrograde filling material.

An in vitro dye leakage study was performed to compare the sealing ability of high copper amalgam with cavity varnish and cermet ionomer cement with and without varnish when used as retrofilling materials. The root canals of 54 maxillary anterior teeth were instrumented and obturated with gutta-percha and sealer. The apical 3 mm of the roots were resected and apical class I cavity preparations were made. The roots were then randomly divided into three groups and retrofilled with one of the experimental materials. After 72 h of immersion in India ink, the roots were cleared and evaluated for leakage with a stereomicroscope. Statistical analysis indicated that the cermet ionomer cement with varnish group had significantly less leakage than the amalgam group (P < 0.0014) and the cermet ionomer cement without varnish group (P < 0.001). There was no significant difference between the other two groups (P > 0.05).

The penetration of smear material into dentinal tubules during instrumentation with surface-active reagents: a scanning electron microscopic study.

Thirty freshly extracted, single-rooted anterior teeth were used. They were divided into three groups and instrumented conventionally with #10 to 50 K files. During instrumentation, the K files in the first group were moistened with saline solution, in the second group with 50% sodium dodecylbenzenesulfonate solution, and in the third group with Sulfapon (sodium salt of sulfonated condensation product of ethylen oxide with a fatty acid) solution. After the experimental procedure the specimens were examined in a scanning electron microscope to observe packing of smear material into dentinal tubules. Results showed the surface-active reagents cause the deeper penetration of the smear material into the dentinal tubules. These findings support the hypothesis that the phenomenon of the packing of smear material into the dentinal tubules is by capillary action and fluid dynamics.