Autologous bone graft is a gold standard for bone augmentation and is routinely applied. As methods for bone augmentation in the dental field, GBR, distraction osteogenesis, bone substitutes of calciumphosphate materials and PRP have already been applied clinically. Furthermore, clinical results of the applications of recombinant proteins of BMP and various growth factors, and the applications of the cells from bone marrow and periostium have been reported. A new method for bone augmentation is thus likely to appear. Society accepts medical treatments that are “effective”, “safe”, “simple” and “economical”. Taking the initials of these words, this paper proposes the concept of “2E2S”. Based on recent studies of bone augmentation from the viewpoint of “2E2S”, the author will predict bone augmentation in the near future.

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Bone augmentation or the alveolar ridge augmentation procedure is inevitable for functional and esthetic prosthetic oral rehabilitation. In this article, conventional alveolar ridge augmentation methods are clinically demonstrated and are reviewed with reference to literature. In addition, distraction osteogenesis (DO), which has drawn considerable attention as a regenerative medicine, was clinically demonstrated. Then, the conventional augmentation methods and distraction are compared. Indications, advantages, and disadvantages of conventional augmentation methods including bone grafts, guided bone regeneration (GBR) and GBR with titanium micromesh (TIME technique) are demonstrated. Next, the mechanisms, indications, and advantages of DO are demonstrated and compared with conventional methods. Although conventional augmentation methods are well established, there are some problems including donor site morbidity and risks of wound dehiscence and infection. DO seems to have advantages compared to conventional augmentation methods. However, there still have some clinical problems such as difficulty in vector control and technique sensitivity. For less morbidity and better efficacy in alveolar ridge bone augmentation, tissue engineering offers potential in the future. However, further basic and clinical study will be necessary for clinical application.

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Bone regeneration is currently considered to be most significant in implantology as regenerative therapy is directly involved and essential in dental prosthetics. The following factors, however, must be clarified before prosthetic treatment can be performed;
1. Necessity of bone regeneration and recovery with individual method
2. Change of regenerated bone
3. Analysis of dynamics which will affect bone resorption
Though these factors are important in prosthetics, dynamic analysis is not performed well even in the existing bone. Clinical follow-ups so far indicate that not only infection but also excessive loading influence most of the cases whose progress is not good. Moreover, there are many challenges to be solved for bone generated by regenerative therapy such as the timing of placing the implant, the timing of loading, conditions for loading and occlusal control.

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Patient: The patient was a 56-year-old female, suffering from severe burning pain in the left maxillary alveolar area. The pain was initiated by periodontal curettage under no local anesthesia. No abnormal local findings in dental X-ray images and no abnormal central nervous system findings in brain magnetic resonance images were observed. Extraction of the tooth temporarily abated her pain, however the pain recurred gradually. Since the observed signs and symptoms of the patient agreed well with the diagnostic standard for continuous neuropathic pain (atypical alveolar pain) of Graff-Radford & Solberg (1992), medications (tricyclic antidepressant, non-steroidal anti-inflammatory drug (NSAID), anxiolytics, topical application of capsacin cream) and supportive psychological therapy have been administered continuously. To measure symptom severity over a long term, daily amounts of taken NSAID and anxiolytics were recorded continuously by the patient in a simple table diary for 7 years. As a result, the total amount of the drugs per month gradually decreased with the passage of time.
Discussion and Conclusions: Clinical evidence regarding the prognosis of continuous neuropathic pain in the orofacial region is obviously insufficient, making it difficult to inform such patients of their prognosis of the disorder on the basis of clinical evidence. In this report, we have plotted the total amount of drugs taken per month by the patient as a good reference for the pain severity and the results clearly suggest that pain severity decreased with time. This kind of information may help both clinicians and patients for case-based explanation of the disorder.

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Purpose: This study examined how the occlusal force is related to the marginal leakage of an abutment tooth where a crown is luted.
Methods: Abutment teeth of the same standard were prepared from extracted human molars and crowns were luted using six kinds of cement.Cyclic loading was then applied to the load point of each tooth under water, at an angle of 45 degrees to the tooth axis in the direction towards the outside or the inside of the occlusal surface with a force of 30 kgf, frequency of 1Hz, and 100, 000 times. After the test, the specimens were immersed for 2 hours in 0.5% basic fuchsin solution and the area of the marginal penetration of each abutment tooth was measured and compared.After loading, the cement at the margin of the crown was observed under a scanning electron microscope (SEM).
Results: Elite Cement 100 (EL) showed severe penetration in the control group.As for Fuji I (FI), Vitremer Luting Cement (VT), Fuji Luting S (FL), and Panavia Fluoro Cement (PF), the marginal penetration directly under the load side of the crown was significantly (p<0.01) greater than at other measurement conditions when the load was applied in the direction towards the outside of the occlusal surface.Panavia Fluoro Cement with the AD gel method (AD) and Relay-X ARC (RX) showed excellent marginal closure even after loading.For SEM observations after loading, Fl and FL showed cohesion failure in the cement and VT and PF showed detachment at the dentin interface.AD and RX did not vary from those in the control group.
Conclusions: This study concluded that the crown luting components of Panavia Fluoro Cement with the AD gel method and Relay-X ARC provide excellent durability against occlusal force.

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Purpose: Most of the mouthguards on the market are inferior in fit and occlusion related to feeling and injury prevention capacity.Therefore, it is necessary to use appropriate custom-made mouthguards. This research aimed to obtain data for the selection, improvement, and spread of mouthguards in the future.A questionnaire survey of dentists who had made four kinds of mouthguard was conducted in a mouthguard seminar.
Methods: The questionnaire survey concerning “feeling”, “difficulty of production”, and “selection when considering use and spread” was done for four kinds of mouthguard.The evaluations were made using a ten-point method with the Kruskal-Wallis test and Mann-Whitney U-test.
Results: Concerning the feeling: The laminated mouthguard was evaluated the highest, followed in order by improvement type, vacuum, and boil & bite. Concerning the production: The evaluation differed from other questionnaire items.No significant difference was found among all four kinds of mouthguard, so there was no difference in the fabrication difficulty. Concerning the selection and spread: The evaluation was almost the same as for the feeling. The laminated mouthguard was assessed to be the best mouthguard.
Conclusions: The boil & bite mouthguard which is widespread was evaluated the lowest in all items except production. Therefore, it is necessary to encourage players to use an appropriate custommade type in view of safety, wearing feeling, and dental occlusion.

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Purpose: This study investigated both the setting expansion and compressive strength of dental gypsum mixed with slightly acidic hypochlorous acid water for the prevention of hospital infection.
Methods: Slightly acidic hypochlorous acid water (PURESTER^® Mp-240 B, Morinaga Milk Industry) was used to mix each of three types of gypsum (model plaster, dental stone and high strength dental stone), and both the setting expansion and compressive strength of these gypsum products were analyzed in comparison with those mixed with tap water.
Results: 1. With regard to the setting expansion, a significant difference was not observed between gypsum products mixed with the two types of water, except for both the model plaster and dental stone 30 minutes after the start of mixing. 2. Regarding the compressive strength, a significant difference was not observed between gypsum products mixed with the two types of water, except for the model plaster 90 minutes after the start of mixing.
Conclusions: From the results of the study, it was revealed that both the setting expansion and compressive strength of gypsum products using the slightly acidic hypochlorous acid water showed almost the same characteristics as those using tap water.

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Purpose: Local application of vascular endothelial growth factor (VEGF) was examined to determine whether it is effective in promoting bone regeneration.
Methods: We operated on live 6-week male SD rat mandibular bone tissue to prepare bone defects in order to attempt the guided bone regeneration (GBR) method.Laboratory animals were divided into 3 groups: the control group, the fibrin group, and the VEGF group.Both radiological observation using soft x-ray and histological observation were performed respectively on the 10th, 20th and 30th days after the operations.
Results: After10days, there was no apparent radio-photographic changes in the bone defects. However, after 20 days there were quite apparent changes, and after 30 days there were even more remarkable changes. The fibrin and VEGF groups changed more than the control group. In our histological observation, we observed rich capillary formation most notably in the VEGF group. This VEGF group also exhibited regeneration in the bone tissue.
Conclusions: Histological and soft x-ray radiological observations indicated that VEGF was effective for blood vessel formation, and VEGF offers potential for bone regeneration.

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Purpose: The aim of this study was to evaluate whether substantial airflow changes occur by changing both jaw position and body posture in normal subjects and patients with obstructive sleep apnea syndrome (OSAS).
Methods: Fifteen normal controls (9 males and 6 females) and 15 male OSAS patients participated in this study. For all subjects their maximum forced inspiratory flow (FIF_25-75) curve was measured in seven positions as follows: a) 0% jaw forward-upright position, b) 0% jaw forward-supine position, c) 50% jaw forward-supine position, d) 75% jaw forward-supine position, e) 0% jaw forwardlateral position, f) 50% jaw forward-lateral position, and g) 75% jaw forward-lateral position.
Results: Although FIF_25-75 was increased by changing the body posture from supine to lateral in normal subjects, it was not increased by increasing the jaw forward position of them.On the other hand, the more forward the jaw position, the more FIF_25-75 increased in OSAS patients.However, it was not increased by changing the body posture of them.There were no significant differences between the 50% forward and 75% forward jaw positions in both groups.
Conclusions: In normal subjects, change of jaw position was more effective than that of body posture for FIF_25-75. However, in OSAS patients, change of body posture was more effective than that of jaw position for FIF_25-75. It was suggested that the treatment effect in the 50% forward position was similar to that in the 75% forward position.

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Patient: The patient was 60-year-old male whose chief complaint was esthetic problem due to median diastema.After orthodontic treatment, an adhesion-fixed metal splint was placed to retain 3+3. After 11 months, the metal retainer on 3 partially debonded.The retainer on 3 was removed and 3 was connected to Al with an adhesion-mechanically fixed metal splint.Six months later, 13 was separated from 2+2 and connected to 14 5 with the conventional crown restoration.
Discussion: The prognosis is good. This result is attributed to the decrease of splint length and the application of the adhesion-mechanical retainer. These seemed to increase the rigidity and prevent deformation of the splint, thus reducing tensile or shear stress applied to the adhesion interface and improving the bonding durability.
Conclusion: This clinical case suggested that the range of splinting and design of retainer affect the durability of adhesion-fixed metal splints.

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