The purpose of this study was to examine the microtensile bond strength of a single-step self-etch adhesive system (Clearfil tri-S Bond and One-Up Bond F Plus) to bovine dentin. Adhesive was applied to a flat dentin surface, and resin composite was bonded according to the manufacturers' instructions. After 24 h storage in distilled water at 37°C, hourglass-shaped specimens were produced. These were subjected to microtensile bond strength testing at a cross-head speed of 1.0 mm/min. The results were analyzed using Student's t-test at a significance level of 0.05. Field-emission scanning electron microscopy (FE-SEM) observations of the fractured specimens and the adhesive-treated dentin surfaces were also conducted. The bond strength of Clearfil tri-S Bond was not significantly different from that of One-Up Bond F Plus, 41.1 ± 10.1 versus 42.3 ± 6.0 MPa. Mode of failure analysis for Clearfil tri-S Bond revealed an equal distribution between the three types of failure, and the predominant mode of failure was adhesive for One-Up Bond F Plus. FE-SEM observations of dentin to which adhesive had been applied revealed that the smear layer had been removed and the collagen fibers exposed. (J. Oral Sci. 49, 183-189, 2007)

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The purpose of this study was to evaluate the effects of functional monomers contained in the primers, as well as alumina particle abrasion on bonding between stainless steel and acrylic resin. SUS XM27 steel was primed with one of the following materials; Alloy Primer, Estenia Opaque Primer, M. L. Primer, and Super-Bond Liquid. Steel disks were either ground flat or alumina-blasted, primed with one of the four agents, and bonded with an acrylic resin (Unifast Trad). Bond strength was determined both before and after thermocycling (2,000 or 20,000 cycles). Among the four priming agents, the Alloy Primer and Estenia Opaque Primer, both of which contain 10-methacryloyloxydecyl dihydrogen phosphate (MDP), exhibited better bonding performance than the others. Alumina air-borne particle abrasion considerably improved the durability of bonding between the steel and the resin material. It can be concluded that alumina blasting followed by priming with an MDP agent is recommended for bonding the resin and SUS XM27 steel. (J. Oral Sci. 49, 191-195, 2007)

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This study evaluated the biologic width in a Chinese population. Ten autopsy specimens of human jaws from 5 male Han Chinese cadavers were collected. Block sections of the jaws were dissected at autopsy. Six-μm-thick, mesio-distal and bucco-lingual sections were cut and stained with hematoxylin and eosin. The widths of the junctional epithelium and connective tissue were measured with a micrometer microscope at the middle of the mesial, distal, buccal, and lingual sites. Differences in biologic width among the 4 measured sites as well as between anterior and posterior teeth were compared. The mean biologic width was 2.17 mm. The width of the junctional epithelium was 1.07 mm, and that of the connective tissue 1.10 mm. The biologic width varied among the 4 sites and the width of the posterior teeth was greater than that of the anterior teeth. (J. Oral Sci. 49, 197-200, 2007)

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Porphyromonas gingivalis gingipains is suspected to be one of the most important causative agents of periodontitis. We postulated that the inhibition of gingipains may reduce the pathogenic nature of P. gingivalis. Anti-P. gingivalis egg yolk antibody (IgY-GP) was isolated from the yolks of hens immunized with purified gingipains. We applied IgY-GP gel subgingivally in periodontitis patients who harbored P. gingivalis in their subgingival flora. Five pairs of contralateral anterior single-rooted teeth were selected. One tooth in each contralateral pair was randomly treated with IgY-GP and subgingival scaling and root planing, whereas the other tooth was treated with SRP alone. The number of P. gingivalis bacteria was assessed by real-time PCR. Bacterial levels were expressed as the percentage of total bacteria. The IgY-GP group had a significant reduction in probing depth. BOP significantly decreased in the IgY-GP group compared to the control group at week 4. The levels of P. gingivalis significantly increased in the control group at week 4, whereas the reduction in the levels of P. gingivalis was sustained in the IgY-GP group. Within the limitations of the present study, IgY-GP was shown to be an effective immunotherapeutic agent in the treatment of periodontitis. (J. Oral Sci. 49, 201-206, 2007)

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The purpose of this study was to compare a high-speed handpiece to an ultrasonic device regarding the time taken for cavity preparation in bovine incisor teeth (n = 12), and to evaluate microleakage after the restorations. Two cylindrical cavities each were prepared on the labial surfaces of 12 teeth. One of them was made with a diamond tip in group 1 (G₁ = 12) coupled with a high-speed handpiece, and the other with a chemical vapor deposition (CVD) tip in group 2 (G₂ = 12) coupled with an ultra-sound device (n = 24). The time taken for each preparation was measured with a stopwatch. The cavities were treated with adhesive (Scotchbond Multipurpose, 3M), restored with composite (Filtek Z250, 3M), finished and polished, and then the prepared teeth were immersed in a 50% silver nitrate solution. The samples were cut in the mesio-distal direction and evaluated for microleakage. Data were analyzed using the Wilcoxon test (P < 0.01). The results revealed that the time taken to prepare cavities was 7.9 times shorter in G₁. There was no microleakage in 100% of the samples indicated by the absence of dye penetration in G₁, and 46% in G₂. It was concluded that the performance of the high-speed handpiece was better than that of the oscillatory system, in terms of both the time taken for preparation and the microleakage. (J. Oral Sci. 49, 207-211, 2007)

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A study was conducted to evaluate in vitro the effect of root surface conditioning with basic fibroblast growth factor (b-FGF) on morphology and proliferation of fibroblasts. Three experimental groups were used: non-treated, and treated with 50 μg or 125 μg b-FGF/ml. The dentin samples in each group were divided into subgroups according to the chemical treatement received before application of b-FGF: none, or conditioned with tetracycline-HCl or EDTA. After contact with b-FGF for 5 min, the samples were incubated for 24 h with 1 ml of culture medium containing 1 × 10⁵ cells/ml plus 1 ml of culture medium alone. The samples were then subjected to routine preparation for SEM, and random fields were photographed. Three calibrated and blind examiners peformed the assessment of morphology and density according to two index systems. Classification and regression trees indicated that the root surfaces treated with 125 μg b-FGF and previously conditioned with tetracycline-HCl or EDTA presented a morphology more suggestive of cellular adhesion and viability (P = 0.004). The density of fibroblasts on samples previously conditioned with EDTA, regardless of treatment with b-FGF, was significantly higher than in the other groups (P < 0.001). The present findings suggest that topical application of b-FGF has a positive influence on both the density and morphology of fibroblasts. (J. Oral Sci. 49, 213-220, 2007)

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This study was designed to survey the incidence of Enterococcus faecalis infection in symptomatic and asymptomatic root canals of necrotic teeth using PCR and to isolate the bacterium for further screening. Sixty patients categorized according to their clinical symptoms were used for sampling by insertion of paper points into the root canals and absorbing all the fluids present within them. The samples were incubated in 1.0 ml 2xYT (containing 16 g bacto tryptone, 10 g yeast extract and 5.0 g NaCl per liter) for 24 h at 37°C without aeration prior to multiplex PCR analysis. To assist the isolation of E. faecalis, sub-samples were further grown in the same medium supplemented with 6.5% NaCl and back-inoculated into bile esculin. Using multiple cultivation-dependent and PCR analyses, 6 cases (10%) of E. faecalis were identified. Four isolates were obtained from asymptomatic cases of chronic apical periodontitis, and the other two were associated with phoenix abscess and acute apical abscess, respectively. No E. faecalis infection was found in 5 patients with acute apical periodontitis or in 9 with chronic suppurative periodontitis. Our results indicate that there is no significant difference in the incidence of E. faecalis between symptomatic and asymptomatic necrotic dental root canals (P > 0.05). (J. Oral Sci. 49, 221-227, 2007)

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A retrospective analysis was conducted on patients diagnosed with and treated for keratocystic odontogenic tumor (KCOT) at Mashhad School of Dentistry between 1996 and 2006. The patients comprised 44 men and 30 women with a mean age of 27.08 years. Among the total of 83 lesions, 56 (67.5%) occurred in the mandible and 27 (32.5%) in the maxilla. Swelling tended to be the most common complaint (45.8%), while 24.1% of the lesions were diagnosed incidentally. Six patients (8.1%) with a total of 15 lesions had nevoid basal cell carcinoma syndrome; 28 lesions (33.7%) were associated with an impacted tooth, and 12 (14.5%) presented daughter cysts. Sixty-six KCOTs were treated by enucleation [5 recurrences (7.6%)], 6 by marsupialization [2 recurrences (33.3%)] and 11 by marsupialization followed by enucleation (no recurrences). KCOTs in the mandible showed a higher recurrence rate than those in the maxilla (10.7% vs 3.7%). Although the demographics of Iranian patients are closely similar to those of other nationalities, in this series KCOTs tended to develop in younger patients with a peak in teenagers. The posterior region of the mandible showed the highest likelihood of KCOT occurrence and recurrence. Marsupialization followed by enucleation resulted in the lowest recurrence rate. (J. Oral Sci. 49, 229-235, 2007)

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Autologous blood injection around the articular capsule and/or into the articular cavity, which is one of the treatments for recurrent temporomandibular joint dislocation, was recently reintroduced. Here, we present the management of recurrent temporomandibular joint dislocation by autologous blood injection in an 84-year-old female. After the treatment, although the right condylar process had settled just beneath the articular tubercle, the dislocation had improved and the patient was able to close her mouth without difficulty. (J. Oral Sci. 49, 237-239, 2007)

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Dentinogenesis imperfecta (DI) type II or hereditary opalescent dentin is inherited in simple autosomal dominant mode with high penetrance and low mutation rate. It generally affects both the deciduous and permanent dentitions. DI type II corresponds to a localized form of mesodermal dysplasia, observed in histodifferentiation. Early diagnosis and treatment are therefore, fundamental, aiming at obtaining a favourable prognosis since late intervention makes treatment more complex. We present two cases of DI type II with the disease affecting three generations of a family in India, and briefly highlight the molecular basis of this disease. (J. Oral Sci. 49, 241-244, 2007)

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Abnormal morphology of the root canal may exist in any tooth, even a maxillary central incisor. In this paper we report endodontic treatment for a rare example of a maxillary central incisor with one root and three root canals. (J. Oral Sci. 49, 245-247, 2007)

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Ectopic eruption into the dental environment is common, whereas eruption into other sites is rare. Diverse anatomical locations such as the mandibular condyle, coronoid process, palate, maxillary sinuses and nasal cavity can infrequently be the site of ectopic tooth eruption. One of the nondental sites for ectopic eruption is the maxillary sinus. Here, we present a case of dentigerous cyst with an ectopic maxillary canine tooth located below the floor of the right maxillary sinus in a 37-year-old man. (J. Oral Sci. 49, 249-252, 2007)

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