Treatment of a vertical root fracture.
This case report presents the successful non-surgical treatment of a vertically fractured tooth by cementation with adhesive resin.
Humans↗
Biomedical subjects
A Funato
Publications and source records attributed to A Funato.
Study of microleakage at Class I cavities prepared by Er:YAG laser using three types of restorative materials.
OBJECTIVE: The purpose of this in vitro study were to investigate microleakage at class I cavities filled with amalgam, composite resin, or glass-ionomer after preparation by Er:YAG laser and to compare the results with those by a conventional method using an air turbine. SUMMARY BACKGROUND DATA: There has been no report of a study of microleakage on class I cavities prepared by Er:YAG laser. METHODS: Ninety-six extracted human premolar and molar teeth were used in this study. Forty-eight class I cavities were prepared by Er:YAG laser and 48 class I cavities by air turbine. After preparation, each of the 2 groups was further subdivided into 3 groups, respectively, and cavities in each of these subgroups were filled by 1 of 3 types of restorative materials. Microleakage at the restored cavities was assessed by the dye penetration method and scanning electron microscopy (SEM). RESULTS: Minimal or moderate leakage was evident at most of the composite resin or glass-ionomer restorations, whereas moderate or severe leakage was observed at most of the amalgam restorations as shown by the dye penetration method. There was significant difference among the 3 restorative materials (p < 0.05), but there was no significant difference in microleakage between the cavities prepared by Er:YAG laser and those by air turbine (p > 0.05). SEM evaluation demonstrated good adaptation with most of the composite resin or glass-ionomer restorations, but amalgam restorations showed slightly poorer adaptation. CONCLUSION: These results suggest that Er:YAG laser is useful for class I cavity preparation from the viewpoint of microleakage.
Composite Resins↗
Mandibular central incisor with two root canals.
A case report of a mandibular central incisor with two root canals and two separate apical foramina is presented. The tooth showed inadequate endodontic treatment and a periapical radiolucent lesion. The lesion healed following endodontic retreatment and proper obturation of both root canals.
Adult↗
Evaluation of calcium hydroxide-containing root canal sealers with an improved rabbit ear chamber.
An improved rabbit ear chamber was used to evaluate calcium hydroxide-containing root canal sealers on their potential to induce dystrophic calcification in connective tissue. Four sealers and two control materials were introduced into the chambers and the effects of these materials on the living vascular tissue were observed continuously under a biomicroscope up to 9 weeks. Conventional histopathological investigation and examinations with a scanning electron microscope and an X-ray microanalyzer were done to supplement the results. Sealapex and Calvital (Ca(OH)2 + iodoform) revealed almost the same tissue reaction as calcium hydroxide-saline paste; they rapidly made a precipitate-barrier of calcium phosphate in the connective tissue, inducing calcification. However, Dentalis KEZ (ZnO-Ca(OH)2 + eugenol) caused mild disorders of microcirculation without calcification, as well as Canals (ZnO + eugenol). New A (Ca(OH)2 + fatty acid) had good compatibility with microvessels as well as New B (ZnO + fatty acid), however they induced no calcification and disintegrated rapidly in the tissue. These sealers were reclassified according to what they actually bring about in the tissue, not according to what they include.
Animals↗
Inhibitory influence of sympathetic nerves on afferent nerve-induced extravasation in the rat incisor pulp upon direct electrical stimulation of the tooth.
Previous studies have shown that sympathetic nerve stimulation reduces afferent nerve-induced vasodilation by mechanisms unrelated to vasoconstriction in the rat incisor pulp. The present investigation concerned whether similar modulatory mechanisms might also influence neurogenic plasma extravasation in dental pulp. Rat mandibular incisors were electrically stimulated and blood flow reactions in the pulp were recorded by laser Doppler flowmetry. Plasma extravasation in the incisor pulp, gingiva and lip were indirectly assessed by the Evans-blue method. Stimulation of teeth with 50 microA (5 min) did not cause increased dye accumulation in the stimulated pulps whereas stimulation with 100 microA significantly increased the dye content in ipsilateral pulps by 32% as compared to controls; 100 microA stimulation was without effect in unilaterally denervated animals. Tooth stimulation with 50 microA (5 min), in the presence of either the alpha-adrenergic blocker phenoxybenzamine (3 mg/kg), or the alpha 1-adrenergic antagonist prazosin (50 micrograms/kg), as well as in chronically sympathectomized animals, significantly increased the Evans-blue content in the stimulated pulps by 47, 83 and 86%, respectively. Application of short trains of impulses (same number of impulses as for the continuous stimulation but producing minimal vasoconstriction) resulted in some dye accumulation, which was enhanced in the ipsilateral pulps in the presence of prazosin (100 micrograms/kg) or after acute resection of the superior cervical sympathetic ganglion by 70 and 64%, respectively. The Evans-blue content in the lip and gingiva was uninfluenced by the tooth stimulation. The results indicate that activation of sympathetic nerves inhibits the afferent nerve-induced plasma extravasation in rat incisor pulp and this effect is mediated by alpha-adrenoceptors not associated with vasoconstriction.
Animals↗
Bio-microscopical observation of dystrophic calcification induced by calcium hydroxide.
Calcium hydroxide paste was introduced into a rabbit ear chamber, and the effect of calcium hydroxide on the vascular tissue was observed under a bio-microscope continuously up to 14 weeks. Many precipitates were observed at the border of living tissue, after the dissolution of microvessels around the paste. They increased both in size and number to combine like a river bank in the first 48 h. After 1 week, microcirculation recovered, and newly-formed capillaries approached the precipitate-bank, the edge of which became smoother as weeks went by. The bank was stable and compatible to microvessels during the observation period. By SEM observation, the width of the bank was from 200 to 400 microns, and the tissue-side of the bank appeared like amorphous lamellae, while the inner-side showed particle-like appearance. EDX examination revealed high peaks of Ca and P similar to calcium phosphate at the tissue-side of the bank, but only Ca peak at the inner-side. The precipitates seemed to have the potential to induce dystrophic calcification by absorbing Ca and P from the tissue.
Animals↗
Activation of sympathetic nerves exerts an inhibitory influence on afferent nerve-induced vasodilation unrelated to vasoconstriction in rat dental pulp.
In order to elucidate a possible influence of the sympathetic nervous system on afferent nerve function, rat mandibular incisors were electrically stimulated and blood flow changes monitored in the incisor pulp of untreated and sympathectomized animals by a laser Doppler flowmeter. Monopolar electrical stimulation of the tooth (200 microA, 5 ms, 40 Hz, 1 s) in normal animals resulted in a transient reduction in pulpal blood flow (PBF) (16% reduction, n = 10) followed by a small but long-lasting increase (11% increase). After administration of phenoxybenzamine or phentolamine (3 mg kg-1, i.v.) the initial dip in PBF was reduced by 59% (P < 0.001) while the subsequent increase was enhanced by 185% (P < 0.001). Similarly, infusion of prazosin (50 micrograms kg-1, i.v.) and idazoxan (0.5 mg kg-1, i.v.) significantly enhanced the increase in PBF by 118 and by 79%, respectively. In chronically sympathectomized animals the increase in PBF was 250% larger than that seen in untreated animals (P < 0.001). This increase in PBF was not further enhanced after alpha-adrenergic blockade. Acute resection of the superior cervical sympathetic ganglion, also resulted in some enhancement (by 56%) of the stimulation-induced increase in PBF (P < 0.01, n = 6). The increase in PBF was unaffected by infusion of timolol (150 micrograms kg-1) and atropine (1 mg kg-1) but was totally abolished by intravenous pre-treatment with capsaicin (1-3 mg kg-1). The present results suggest that activation of sympathetic nerves exerts inhibitory effects on the afferent nerve-induced vasodilation in the rat incisor pulp unrelated to sympathetic vasoconstriction.
Adrenergic alpha-Antagonists↗
A study on the removal of the melanin pigmentation of dog gingiva by CO 2 laser irradiation.
Removal of melanin pigmentation of the gingiva with CO 2 laser irradiation was investigated. The melanin-pigmented gingiva of 5 dogs were classified according to the degree of gingival pigmentation (slight, moderate, severe) and its extent (local, extensive). CO 2 laser was irradiated on the surface of the pigmented gingiva under the following conditions; defocused beams of spot size 4 mm, irradiation time 0.2(S), output 6-8(W)). That is, the irradiation energy density was 9.6-12.8 J/cm 2. The irradiated gingiva was examined macroscopically and histopathologically. The histopathological changes were investigated by hematoxylin-eosin staining and Masson staining for the differential diagnosis of melanin pigmentation cells. These examinations were done one week and three weeks after the laser irradiation. Immediately after irradiation, the gingiva surface showed white color and bulla-like appearance. One week after irradiation, the pigmentation of the lased gingiva disappeared in all cases macroscopically. Histologically, the pigmented-laden cells could not be found and no inflammatory cell infiltration was observed. Three weeks after irradiation, no reappearance of pigmentation was observed in either macroscopical or microscopical investigations excluding severe/extensive cases. These findings suggested that it is possible to remove gingival melanin pigmentation by CO 2 laser irradiation.
Animals↗
Effects of Nd:YAG laser irradiation on microcirculation.
Changes in microcirculation after irradiation by Nd:YAG laser were evaluated using the "rabbit ear chamber" method. Morphological changes of the vascular network related to time elapsed after irradiation was observed by a microscope-video system. Findings such as vascular shrinkage, degeneration, coagulation, and stasis associated with irradiation were recognized shortly after the Nd:YAG laser was applied. Damage increased with irradiation energy increase. Expansion of the stasis region and appearance of hemorrhagic spots decreased, and vascularization began. On the seventh to tenth days, the damaged region was restored by a newly formed capillary network. When no change was noticed microscopically in the case of low-energy irradiation, transient increase of blood flow, determined by laser Doppler flowmeter, was observed. The results suggest that the effects of Nd:YAG laser irradiation are primarily thermal. It has good hemostatic and coagulation ability and some of the changes are nerve-mediated by low-energy irradiation.
Animals↗
Effects of Nd:YAG laser irradiation on microcirculation.
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Animals↗
Scanning electron microscopic study of dentin walls of the pulp chamber by a replica technique.
Precise replicas of the pulp chamber were made with a low-viscosity synthetic resin and examined with a scanning electron microscope. As a result, it was confirmed that the pulp horns and the pulp roof were clearly observed at both low and high magnification by this replica technique. Furthermore, interesting findings were made. That is, a vessel-like linear ridge or groove, measuring 5 micron in diameter, was observed on the surface of the replica. The ridge or groove ran across the top of the pulp horn to the pulp roof in the direction of the other horns. Such a linear ridge or groove was found in 32 of 50 specimens (64%). It may be interpreted that there was a stringy structure embedded in the calcospherites beneath the predentin. However, the origin of these structures could not be determined in this experiment.
Dental Pulp↗