Adhesiveness between the resin shell and composite resin was examined. As the resin shell, SR-PE-ISOCETTE, made from thermosetting crown and bridge resin, was used. The shear bond strengths between the resin shell and photocurable composite resin bonded by various methods were measured after 1-day of immersion in water at 37°C.
Super-bond C & B treatment to the resin shell effectively improved the adhesiveness, giving a bond strength of about 14 MPa. Clearfil new bond, Clearfil porcelain bond, Unifast and MMA/TBBO treatment gave almost the same bond strengths of about 7-9 MPa. Silane coupling agents were not effective for improving the bond strength. It was revealed that 4-META was necessary for obtaining good adhesion between SR-PE-ISOCETTE and composite resin.

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Age is known to be one of the factors which affect the rate of collagen and protein turnover in the connective tissues of the periodontium. The aim of the present study was to determine the levels of hydroxyproline (Hyp) and total protein in both the gingiva and gingival crevicular fluid (GCF) of periodontally healthy human subjects of two different age groups. The subjects of the young group were selected from among patients scheduled for extraction of upper and lower first or second premolars for orthodontic reasons. The second (older) group included individuals whose teeth were to be extracted for endodontic reasons. GCF was obtained before gingival sampling. The tissues surrounding the sockets were harvested immediately after extraction of the indicated teeth. All samples were analyzed biochemically. No significant difference was found in gingival and GCF levels of Hyp (which is unique to collagen) between the groups. Total protein levels in gingiva were significantly higher in the young group than in the older group. GCF total protein levels showed no significant difference between the groups. The higher gingival protein levels in the younger group seem to conform to previous findings.

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In this study, surface corrosion of carved and polished specimens of conventional and high-copper amalgams was investigated. The specimens were studied to detect surface corrosion after immersion in artificial saliva for 48 h or 1 year, and later investigated by SEM. Corrosion was greatest in 1-year-immersed carved conventional amalgam specimens. The surface was very rough with the contours of the particles visible and deep holes opening at the surface. High-copper amalgam specimens showed less corrosion than conventional amalgam specimens.

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An investigation was undertaken to determine whether analgesics and their derivatives (13 compounds), and anti-inflammatory drugs (4 compounds) had mutagenicity. Rec-assay was used to clarify specific DNA-damaging properties, and the Ames test was used to find back-mutations, using S-9 fractions obtained from the liver of 4 animal species pretreated with polychlorobiphenyl.
In the Rec-assay, salicylic acid (2 mg), aspirin (5 mg), benzoic acid (4 mg), sulpyrine (0.4 mg), indomethacin (0.1 mg), oxyphenbutazone (0.1 mg) and diclofenac sodium (0.1 mg) showed a DNA-damaging tendency.
In the Ames test, mutagenicity of methyl salicylate was demonstrated using the Salmonella typhimurium TA98 strain upon addition of hamster S-9 mixture. Weak mutagenicity was also found using the TA100 strain with rat S-9 mixture for salicylic acid, sulpyrine, indomethacin and oxyphenbutazone, and with hamster S-9 mixture for methyl salicylate, acetaminophen and phenacetine.

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A series of studies was conducted on the synthesis of polyfunctional cyclophosphazene monomers having radiopacity and a polymerization group in the same molecule, and their properties and applicability to composite resin were examined. Using octachlorocyclotetraphosphazene, P₄N₄Cl₈ (4PNC), monomers were synthesized by replacing the 1-4 of chlorine (Cl) with p-bromophenol (BrC₆H₄OH, BrPh), and replacing the residual number of C 1, 7-4, with 2-hydroxyethyl methacrylate [CH₂ : C (CH₃) COOCH₂CH₂OH] (HEMA), so as to obtain four kinds of transparent monomer having radiopacity and a polymerization group in the same molecule. We then analyzed these monomers and examined their physical properties after bulk-polymerization. Next, we prepared an organic composite filler using 4PN- (BrPh) ₃- (EMA) ₅ monomer, which showed comparatively good radiopacity, to produce a new experimental radiopaque composite resin.
Although radiopacity improved in accordance with the increase in the number of BrPh molecules replaced, the mechanical properties of the polymer became poorer. Similarly it was proved that the radiopacity of composite resin made with 4PN- (BrPh) ₃- (EMA) ₅ monomer was equivalent or even superior, compared with the radiopacity of the front tooth.
Consequently, it was shown that these synthesized monomers can be applied to visible light-cured radiopaque composite resin.

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Blood flow to the maxillary and mandibular gingivae was determined in 9 subjects under both normal conditions and in inflammation using the ¹³³Xe clearance technique. A total of 36 sites (18 healthy and 18 inflamed) were selected for ¹³³Xe injection. The clearance of radioactivity was monitored by a gamma camera. The calculated mean blood flows were 51.1 ± 11.4 and 48.7± 6.7 m1/100 g/min to the normal maxillary and mandibular gingivae, respectively. In inflamed gingiva, the corresponding mean blood flows were 55.0± 13.0 and 54.7± 11.7 ml/100 g/min, respectively. A statistical comparision of the healthy and diseased sites was done according to the paired t and Student's t tests. The difference between the sites was not significant (p > 0.05) in the maxilla, but significant (p < 0.05) in the mandible. There was no significant difference (p > 0.05) when the total healthy and diseased sites were compared.

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A case of adenocarcinoma arising in the lip of a 20-year-old Japanese man is reported. After electro-irradiation therapy with a dose of 30 Gy, one third of the upper lip, including part of the cheek, was excised. Immediate reconstruction using transpositional flaps of the buccal skin and mucosa, and a functional neck dissection were performed. Nineteen months after surgery, there was no local recurrence or distant metastasis, and desirable results were obtained both functionally and cosmetically.

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Special techniques of skeletal intermaxillary fixation are described, which may be used in edentulous patients or those with many missing teeth or multiple fractures of the jaw. Two such cases are described in which the usual fixation techniques could not provide sufficient stabilization because of linguoversion and mesioversion or lack of teeth, resulting in inability to maintain a vertical interocclusal relationship.
Two long eight-hole Champy miniplates were therefore used distally to the canines on both sides. In the first case, they provided fixation following a sagittal ramus osteotomy to advance the mandible, and in the second case they were used in the treatment of a mandibular fracture.

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