CV
Doctor Junji Tagami, Prof. Emeritus at Tokyo Medical and Dental University(TMDU), achieving his DDS in 1980 and his PhD in 1984. He was appointed to the Professor and Chair of Cariology and Operative Dentistry, Graduate School at TMDU from 1995 to 2021. He continues clinical, academic and educational activities as the director of Aoyama Quartz Dental Clinic and Chulalongkorn University and University of Indonesia as the Visiting Professor. He is a prolific author who has contributed more than 500 papers to per-reviewed international journals and some 200 papers to Japanese academic journals in the fields of cariology, tooth-colored dental restorative systems, the bonding of materials to dental tissues. He was awarded Honorary Degrees from King's College of London and Mihidol University in Thailand, the distinguished scientist award, Wilmer Souder Award, from IADR, and The President’s Award of Japanese Association of Dental Science.
Keys to Obtain the Invisible Margin of Direct Composite Restoration
The invisible margin of the restoration is one of the most important factors for the aesthetic restorations. In the direct composite resin restoration, its margin is frequently located at the labial surface of incisors. The color matching between tooth substance and composite resin is influenced by the shades of the marginal tooth substance and composite resin. The chameleon effect of enamel was confirmed to be higher than that of the composite resins. Also the enamel of young patients exhibited higher chameleon effect than that of the elderly patients. As for the composite resin materials, its chameleon effect is variable among products. the light diffusion effect is a significant factor to determine the chameleon effect of the composite resin. Also the translucency of the material is very effective to reflect the color of the cavity floor. The appropriate selection of the shade of composite resin according to the clinical situation is very important. The structural color effect is utilized for the composite resin materials. Its mechanism and clinical implication are also discussed in the lecture.
Learning objectives
- Photonic characteristics of tooth substance: The photonic characteristics of enamel and dentin are reviewed and the chameleon effect of enamel is discussed. especially the enamel of young patients exhibits higher chameleon effect than that of the elderly patients. Those information helps the clinicians to select the composite resin material
- Photonic characteristics of composite resin material: Composite resins are provided according to their shades. In addition to the shade of the material, its light diffusion effect and light transmission are also significant to obtain the color matching with the surrounding tooth. The structural color effect is also a novel technology in composite resin. Understanding its mechanism will help us to effective implication in the clinic
- Finishing the margin of restoration is an important factor for the invisible margin of the composite resin restoration. However, enamel margin is a very sensitive to the risk of fracture, caused by the preparation procedure and shrinkage stress of the composite resins. Optimum bevel preparation technique and bonding strategy are indicated in the lecture
Aesthetic Direct Composite Restoration Beyond the Biomimetic Concept
The bond strength of the recent adhesives to both enamel and dentin is much higher than the tensile strength of tooth itself. From this, the restored tooth is expected to show higher strength than natural tooth. At the bond interface, the mechanically and chemically reinforced dentin and enamel are created by the excellent adhesive resin materials. The newly created tooth substances are named as the super dentin and super enamel, which are more durable than natural tooth substance. The bonding to the caries affected dentin is also recovered by modifying the smear layer using the deproteinizing treatment. By means of these methods, the so-called hopeless teeth became possible to be survived by adhesive restoration. In the cases of the endo-treated root, the direct crown restoration is also applicable and being reported to exhibit its excellent clinical performance for long period. The factors to affect the clinical result is being clarified. The clinical conditions for the success of the hopeless teeth restoration is discussed in the lecture.
Learning objectives
- Reinforcement of dentin and enamel at the bond interface: The tooth substances including enamel and dentin are modified by the bonding procedures, showing the chemically durable property. The selection of the material to create the super dentin and super enamel is indicated
- The technique to increase the bonding to caries affected dentin is explained. The technique is said as the smear layer deproteinization (SLDP) method. Its procedure and mechanism is demonstrated
- The direct restoration technique for the endo treated root building up the whole crown with composite resin is introduced with a clinical evaluation report. The technique is said as the direct crown restoration. The factors affecting its clinical performance is discussed and the best procedures will be demonstrated. The extended application of direct composite restoration is also discussed from the viewpoint of the Minimally Invasive Dentistry