This study proposed a protocol of prognostic evaluation system for the purpose of improving the quality of implant technology. Cases were divided into tumor and non-tumor cases according to the criteria proposed by Katagiri (2002). The biopsy factor / five items (B1 to B5) shown below were extracted, and each item was scored on a four-point scale (0 to 3) and evaluated.
B1: Presence or absence of peri-implant inflammation (nonspecific reaction), and the severity
B2: Presence or absence of specific reactions suspected of severe infection or allergy, and the severity
B3: Presence or absence of involvement of peri-implant epithelium, and the severity
B4: Presence or absence of bone resorption and destruction, and the severity
B5: Presence or absence of implant instability, and the severity [however, the key point for a clinically stable state is evaluated by whether bony encapsulation dominates over fibrous encapsulation]
Considering the cost-effectiveness in the choice of staining methods necessary for evaluation, HE staining and Azan staining are effective for studying general morphology, PAS reaction and Grocott staining for demonstrating fungi and general bacteria, and immunostainig (AE1/AE3) for confirming epithelial or immune cells.

View full abstract

For the purpose of improving caries detection and enhancing the quality of caries treatment including prognosis and prevention, we used a transilluminating caries detection method by applying a spotlight from the light guide of a multi-purpose K-dental fiberscope proposed by Katagiri (1980), in bright field and dark field. To validate the usefulness of this method, we studied the second deciduous molar and obtained useful findings from the transilluminating effect.
1. According to the differences in conditions of illumination and incidence accompanying qualitative changes of the teeth studied, the images can be divided into the following: (1) general reflection image (bright field range, shadowless lamp illumination alone from the front at an illumination angle of 0 to less than 20°), (2) irregular reflection image (intermediate range, spot light illumination alone from the front at 0 to less than 45°), (3) general transillumination image (dark field range, incidence from the inside at 0 to less than 20°), (4) type I irregular transillumination image (intermediate range, illumination from the front at 45 to 90°), and (5) type II irregular transillumination image (bright field range under shadowless lamp, incidence from the insideat 45 to less than 90°).
2. The type I irregular transillumination image shows not only the transillumination image but also effect image resembling irregular reflection image, and type II irregular transillumination image shows not only irregular reflection image but also transillumination effect weaker than type I. Both provide useful images of illumination effects.

View full abstract

Caries are treated by conservative restoration, but expansion and development of caries may cause pulpitis or periodontitis, and caries is considered a multi-factorial disease sharing many interrelating risk factors with the above dental diseases. These diseases usually start from the deciduous dentition to mixed dentition stage. Except some cases showing rapid progression, in most patients these diseases become chronic from the permanent dentition stage, and expand or progress over a prolonged period until the teeth are lost ending with an edentulous jaw. The conventional rotational cutting tool commonly used in the narrow buccal cavity has a high risk of causing damage to the oral mucosa of the tongue, lips, gingival, cheek and mouth floor in elderly patients seeking dental care who have delayed reflex, or conversely in small children who tend to move without warning. To solve this problem, we combined the conventional rotational cutting tool with an ultrasonic cutting system as well as a nondestructive caries detector using the transillumination effect provided by the guide portion of a multipurpose K-dental fiberscope. In this study, we validated this novel system using an in vitro simulation model and obtained useful clinical findings.

View full abstract

Previously, we reported that the structure of new bone formed around implants and the crystalline structure differed from the cortical bone. Furthermore, we analyzed the crystallization of new bone in a small region after implantation, and detected CaCO₃ (calcite and aragonite) in the new bone. Then, we analyzed the cortical bone of a normal rabbit tibia by Imaging Plate-Micro-X-ray diffraction (IPMicro-XRD), and detected CaCO₃ (calcite) in the normal bone. The involvement of CaCO₃ in the normal bone suggests that it is important to re-evaluate the mechanism of the bone.

View full abstract

Dental pulps have recently been recognized as potential bio-resources for the regeneration of mineralized and neuronal tissues. In this study we estimated the expression of mRNA and protein of bone morphogenetic proteins (BMPs) in human dental pulps. The dental pulps, which were obtained from adult third molars, showed the expression of BMP-2, -4, -6, and -7 mRNAs by RT-PCR. In addition, the mRNA expressions of other hard tissue-related proteins, such as alkaline phosphatase (ALP), osteocalcin (OCN), osteopontin(OPN), dentin sialoprotein (DSP), and dentin matrix protein 1 (DMP1), were detected by RT-PCR. The lysate of human dental pulps gave a main band at 50 kDa and several minor bands at 32 to 16 kDa by immunoblotting with anti-BMP-2 antibody. The construct of human BMP-2 with FLAG epitope was prepared, and the fusion protein was expressed in COS-7 cells. The FLAG-tagged BMP-2 gave an identical band at 62kDa by immunoblotting using both anti-FLAG and anti-BMP-2. These results suggest that anti-BMP-2 is highly specific to human BMP-2, and that BMP-2 is mainly present as an immature high molecular weight precursor in normal, adult dental pulps.

View full abstract

The laboratory generally used method to identify a kind of bacterium by culture result using for example selective mediums, and PCR analysis. We examined a simple method, which doesn’t need advanced specialized technique. The intraoral bacterium from a human patient was cultured in an anaerobic environment. The result of the intraoral bacterium is reported here.

View full abstract

The purpose of this study was to evaluate synthetic calcium phosphates and animal bones using Raman spectroscopy, and explore the possibility of its application in characterizing newly formed bone around implants. Synthetic calcium phosphates (monobasic calcium phosphate, dibasic calcium phosphate and tribasic calcium phosphate), hydroxyapatite and rabbit bones with and without implants were analyzed in this study. Slight differences in the Raman bands among the 3 types of synthetic calcium phosphate and hydroxyapatite were observed. Furthermore, a 3cm^-1 difference was noted in the bands of the main PO₄^3- in rabbit’s bone formed around the implant compared to the existing bone, suggesting a difference in the molecular structure between the existing and newly formed bone.

View full abstract

We obtained interesting results when analyzed the bones of the aged rats by the Micro-XRD. The samples were in a rat thighbone after 96 weeks and in rat thighbone after 8 weeks and 48 weeks as control group. The samples were analyzed ten points and 1,800 sec by the Micro-XRD. The crystal after 96 weeks was worse than control group.

View full abstract