• Journal of the korean academy of Pediatric Dentistry
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• v.39 no.1
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• pp.36-42
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• 2012

Odontomas generally appear as small, solitary, or multiple radio-opaque lesions found on routine radiographic examinations. It is a comparatively common odontogenic tumor, and may lead to interfere with the eruption of its associated tooth. In general, odontomas occur more often in permanent dentition and are very rarely associated with primary teeth. This report deals with five rare cases of primary teeth impaction associated with odontomas, with spontaneous eruption occurring in all five cases after simple surgical removal of the odontoma. Impacted primary teeth may be associated with defects in development and eruption of their permanent successors, and thus long-term observation is necessary until the permanent successors erupt.

• Journal of Dental Rehabilitation and Applied Science
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• v.30 no.4
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• pp.329-338
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• 2014

Patients who lost molars from dental caries or periodontitis have difficulty in maintaining their vertical dimension because their incisors and premolars also show vertical tooth movement. Missing posterior molars leads to occlusal interference and collapse of occlusal plane due to extrusion of opposite teeth and tipping of adjacent teeth. When this condition persists over long time, mandible moves forward, so it causes mobility and labioversion of upper incisors. This progress cannot be stopped spontaneously and the situation gets worse and worse. Therefore, for a patient with pathologic teeth migration caused by chronic periodontitis, interdisciplinary approach which is including periodontal treatment, orthodontic teeth alignment and prosthetic restoration of missing molars is required. This case report shows successful multidisciplinary approach to a patient who lost vertical dimension due to severe dental caries and periodontitis.

• Restorative Dentistry and Endodontics
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• v.22 no.2
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• pp.519-535
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• 1997

The responses of human pulp fibroblastic cells to Ga-As Semi-Conductor-Dens-Bio Laser (Frequency: 5 Hz~10,000 Hz Model: SD-101A RCA, U.SA)) were examined in vitro using pulp fibroblastic cells obtained from the pulp tissue of human tooth. The mitogenic effect of soft laser was assessed by measuring the MTT assay. The morphologic effect for soft laser showed under the scanning and transmission electron microscopy. The results as follows; 1. The mitogenic response of the soft laser was not observed until 4th time of radiation, while the mitogenic response at 4th time increased mitogenic effect by as much as 1.7 fold compared to the control value. 2. The mitogenic response of the soft laser on pulp fibroblast differ from the mitogenic response on other fibroblasts. 3. In scanning electron microscopic study, The microvilli of cell surface increased gradually with width and length after laser radiation, it demonstrate that development of microvilli have close connection with differentiation of cells. 4. Under the transmission electron microscope, The laser-treated cells maintained their elongated shape and a high degree of cellular polarization. The large cell body containing a well developed Golgi complex, a large number of profiles of rough endoplasmic reticulum, and great numbers of mitochondria. 5. The laser-treated cells maintained the long straight bundles of closely apposed microfilaments or individual filaments forming a cross-linked network. These findings suggest that the laser may have important roles in promotion of pulp healing and consequently may be useful for clinical application in pulp regenerative procedures.

• The Journal of Korean Academy of Prosthodontics
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• v.40 no.6
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• pp.590-596
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• 2002

The resin : metal interface is at the basis of most bonding failures in resin-bonded prosthesis. Although debonding has been a problem with adhesive fixed partial dentures, various dentists classify them as long-term restorations. The advantages of resin-bonded fixed partial dentures include minimal tooth reduction and the possibility of rebonding. if resin-bonded protheses can be easily rebounded, it is of clinical importance to know if the lutingagents rebond as well the second time as they did originally. Several retentive systems for resin-to-metal bonding have recommended. Treatments such as electrolytic etching and silicone coating, despite the good result of bond strength, have proved to be time-consuming and technique-sensitive. Therefore a simple and more reliable method is desirable. This study evaluated the effect of metal surface treatments on the rebond strength of panavia 21 cement to a nickel-chromium(Ni-Cr) alloy. The samples were received the following surface treatments : Group No.1 (control or served as the control) treatment with sandblasting with 50um aluminum oxide and ultrasonically cleaned for 10minutes in double-deionized water, Group No.2 were no surface treatments. Group No.3 were treated with metal primer. Group No.4 were treated with sandblasting as previously described, and then metal priming. From the analysis of the results, the following conclusions were drawn. 1. Sandblasting and metal priming appears to be an effective method for treatment of metal after accidental debonding. 2. Group without surface treatment had significantly lower bond strengths compared with other groups. 3. The combination of sandblasting and metal priming may not develop superior bonding strengths compared with other techniques that used the Ni-Cr alloys. 4. Combination of cohesive and adhesive failures were the most common type observed. The results support the use of sandblasting as a viable procedure when rebonding accidentally lost adhesive partial denture. We concluded that sandblasting and metal priming of metal surface before bonding could provide the adequate bond strength during rebonding of resin-bonded fixed partial denture.

• The Journal of Korean Academy of Prosthodontics
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• v.45 no.3
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• pp.295-302
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• 2007

Statement of problem. Fracture of the tooth-colored superstructure material is one of the main prosthetic complications in implant-supported prostheses. Purpose. The purpose of this in vitro study was to compare the fracture strength between the cement-retained implant-supported metal-ceramic crowns and the indirect composite resinveneered metal crowns under the vertical compressive load. Material and methods. Standard implants of external type (AVANA IFR 415 Pre-mount; Osstem Co., Busan, Korea) were embedded in stainless steel blocks perpendicular to their long axis. Customized abutments were fabricated using plastic UCLA abutments (Esthetic plastic cylinder; Osstem Co., Busan, Korea). Thirty standardized copings were cast with non-precious metal (Rexillium III, Pentron, Walling ford, Conn., USA). Copings were divided into two groups of 15 specimens each (n = 15). For Group I specimens, metal-ceramic crowns were fabricated. For Group II specimens, composite resin-veneered (Sinfony, 3M-ESPE, St. Paul, MN, USA) metal crowns (Sinfony-veneered crowns) were fabricated according to manufacturer's instructions. All crowns were temporary cemented and vertically loaded with an Instron universal testing machine (Instron 3366, Instron Corp., Norwood, MA, USA). The maximum load value (N) at the moment of complete failure was recorded and all data were statistically analyzed by independent sample t-test at the significance level of 0.05. The modes of failure were also investigated with visual analysis. Results. The fracture strength of Sinfony-veneered crowns ($2292.7{\pm}576.0N$) was significantly greater than that of metal-ceramic crowns ($1150.6{\pm}268.2N$) (P < 0.05). With regard to the failure mode, Sinfony-veneered crowns exhibited adhesive failure, while metal-ceramic crowns tended to fracture in a manner that resulted in combined failure. Conclusion. Sinfony-veneered crowns demonstrated a significantly higher fracture strength than that of metal-ceramic crowns in cement-retained implant-supported prostheses.

• Journal of Periodontal and Implant Science
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• v.38 no.2
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• pp.225-230
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• 2008

Purpose: Many clinical studies have reported that higher success rates are achieved with teeth that have immature roots than other autotransplanted teeth that have more immature root. However, based on date published recently, the success rate of autotransplantation of teeth with complete root formation was higher. The purpose of this study was to examine the long term(2 to 6 years follow-up) success rate of autotransplantation of third molar with complete root formation and to discuss some conditions and prerequisites for success. Materials and Methods: 26 sites of 24 patients aged 26 to 55 (mean age 40.8) were autotransplanted with third molars with complete root formation. These cases were followed for 2 to 6 years after surgery. The success criteria included (1) no discomfort during functioning (2) absence of progressive root resorption and alveolar bone resorption. Result: Of 26 teeth 5 teeth were failed, therefore success rate is 81%(21/26 teeth). The results suggested that higher success rate is acquired from (1) extraction socket due to dental caries (2) mandibular recipient site (3) patient younger than 40 years old. Autotransplantation of third molar to replace molars with advanced periodontal disease also showed considerably high success rate(84%). Conclusion: With appropriate case selection, autotransplantation of third molar with complete root formation remains a viable alternative for replacing a missing molar tooth.

• Journal of Dental Rehabilitation and Applied Science
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• v.29 no.2
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• pp.195-202
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• 2013

The relationship between occlusion and periodontal health has been studied extensively. Despite this, there are few reports on the effects of intentional passive eruption (IPE) using an occlusal reduction. The aim of this clinical report was to present the favorable long-term results of IPE using an occlusal reduction combined with scaling and root planing. After periodontal examination, teeth were diagnosed as moderate chronic periodontitis with intrabony defects and mobility. IPE was performed using periodic occlusal reduction combined with initial periodontal therapy. All teeth examined healed uneventfully and the patients did not complain of discomfort. It has been clinically well maintained during 8 years after completion of IPE. Overall, these results suggest that the IPE would be helpful in improving periodontal health.

• Journal of the korean academy of Pediatric Dentistry
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• v.25 no.1
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• pp.197-208
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• 1998

This study was carried out to compare the amount of the maxillary bone remodeling and tooth displacement in each three maxillary superimposition methods, Ricketts, Best-fit, Structural method. Forty cases of the lateral cephalometric radiographs from 27 boys and 13 girls who had been treated to correct anterior cross-bite were selected for the study. The initial radiographs were taken at about 8-year-old and the second radiographs were taken in about 3.3 years later. Followings were the results: 1. With the Structural method, backward movement was shown in PNS, while forward movement was observed in ANS and point A. With the Ricketts method, however, all structures were shown significant backward movement comparing with Structural method(P<0.05). With the Best-fit method, the amount of horizontal movement was similar to that of the Structural method(P>0.05). 2. The palate seemed to be moved downward with Structural method, but there was no measured downward remodeling on nasal floor with Ricketts and Best-fit method(P<0.05). 3. Comparing with Structural method, Ricketts and Best-fit method significantly underestimated the eruption of the teeth by 20% to 30% (P<0.05). 4. The Structural method showed the anteroinferior rotation (43%) and posteroinferior rotation(57%) of the palatal plane, while the Best-fit method showed mostly anterosuperior rotation(87%), but no change was found in the Ricketts method. 5. With the Structural method, there was a statistically significant correlation between the amount of the rotation of the palatal plane and that of N-S line(r=0.86). 6. The measured angles of the long axis of the incisors and molars showed no significant difference in each 3 methods(P>0.05).

• Journal of the korean academy of Pediatric Dentistry
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• v.32 no.3
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• pp.537-542
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• 2005

Dentofacial trauma can result in tooth fracture, avulsion, facial bone fracture. The Unites states and Japan mandated the use of mouthguards for contact sports. But, Korean didn't. Mouthguards divided into ready-made type and custom-made type. Mouthguards protect the lips, intraoral soft tissues, teeth and provide the mandible with resilient support to prevent jaw fracture and dislocations. Sports-related accidents have been reported to be one of the most common causes of dentofacial trauma. Sports trauma of involving teeth with incomplete root formation cause long chair time, multiple visit, economic considerations, additional dental services. So, mouthguards can offer considerable protection against sports-related trauma.

• Journal of Dental Rehabilitation and Applied Science
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• v.32 no.4
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• pp.307-313
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• 2016

Overdenture is one of the methods of patients with severely worn dentition. Remaining natural teeth help preserve alveolar bone and proprioception and provide rigid support. Also, overdenture distributes the concentrated stress applied to the abutment tooth and denture supporting tissues. There is an advantage that it can provide long-term stability to denture. In this case, the patient with only a few teeth due to severe wear and caries was satisfied with good function and favorable esthetics by using overdenture.