• The Journal of Korean Academy of Prosthodontics
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• v.31 no.4
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• pp.580-610
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• 1993

The purpose of this study was to analyse the deflection and stress distribution at the supporting bone and it's superstructure by the alteration of angulation between implant and it's implant abutment. For this study, the free-end saddle case of mandibular first and second molar missing would be planned to restore with fixed prosthesis. So the mandibular second premolar was prepared for abutment, and the cylinder type osseointegrated implant was placed at the site of mandibular second molar for abutment. The finite element stress analysis was applied for this study. 13 two-dimensional FEM models were created, a standard model at $0^{\circ}$ and 12 models created by changing the angulation between implant and implant abutment as increasing the angulation mesially and distally with $5^{\circ}$ unittill $30^{\circ}$. The preprocessing decording, solving and postprocessing procedures were done by using FEM analysis software PATRAN and SUN-SPARC2GX. The deflections and von Mises stresses were calculated under concentrated load (load 1) and distributed load(load 2) at the reference points. The results were as follows : 1. Observing at standard model, the amount of total deflection at the distobuccal cusp-tip of pontic under concentrated load was largest of all, and that at the apex of implant was least of all, and the amount of total deflection at the buccal cusp-tip of second premolar under distributed load was largest of all, and that at the apex of implant was least of all. 2. Increasing the angulation mesially or distally, the amounts of total deflection were increased or decreased according to the reference points. But the order according to the amount of total deflection was not changed except apex of second premolar and central fossa of implant abutment under concentrated load during distal inclination. 3. Observing at standard model, the von Mises stress at the distal joint of pontic under concentrated load was largest of all, and that at the apex of implant was least of all. The von Mises stress at the distal margin of second premolar under distributed load was largest of all, and that at the apex of Implant was least of ail. 4. Increasing the angulation of implant mesially, the von Mises stresses at the mesial crest of implant were increased under concentrated load and distributed load, but those were increased remarkably under distributed load and so that at $30^{\circ}$ mesial inclination was largest of all. 5. Increasing the angulation of implant distally, the von Mises stresses at the distal crest of implant were increased remarkably under concentrated load and distributed load, and so those at $30^{\circ}$ distal inclination were largest of all.

• Journal of the Korean Academy of Esthetic Dentistry
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• v.19 no.1
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• pp.22-26
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• 2010

• 대한치과보철학회:학술대회논문집
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• 2000.04a
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• pp.67-67
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• 2000

• 대한치과보철학회:학술대회논문집
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• 2003.04a
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• pp.96-96
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• 2003

• The Journal of the Korean dental association
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• v.37 no.4 s.359
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• pp.246-249
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• 1999

상악 전치부 임프란트 보철환자에서 screw-retained보철과 cement-retained 보철의 비교분석(Screw-retainde vs. cement-retained implant prosthesis in anterior edentulous area)

• 대한치과보철학회:학술대회논문집
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• 2004.04a
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• pp.88-88
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• 2004

• The Journal of Korean Academy of Prosthodontics
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• v.40 no.4
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• pp.374-385
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• 2002

A total of 605 implant fixture prosthesis delivered by 3 clinics and 2 laboratories were examined in this study, The object of this study was to determine the proper length of screw head. The depth of access hole were measured and compared to the type of fixture, abutment, gold screw and prosthesis. The results were as follows : 1 The average number of fixtures per patient were 2.97. 2. The number of fixture installed in the upper posterior area are 327(55.56 %), the upper posterior area 171 (28.25%). 3. The depth of access hole is 4.23 mm in shallow area, and 5.46 mm in deep area and the differences were 1.23 mm. 4. The average depth of the aceess hole of the UCLA abutment were 5.02 mm. 5. The number of 4-5 mm access hole depth were 60(22.39%) in abutment screw level and the number of 4-5 mm depth in fixture level were 101 (29.19%). 6. In the shape of screw head, hexed type were 576(95.21%), slotted type were 29(4.79%).

• Journal of Technologic Dentistry
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• v.30 no.2
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• pp.57-63
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• 2008

Statement of problem: Conventional techniques for implant framework fabrication produce significant error that is inconsistent with passive-fit requirement for osseointegrated implants. One of the etiologic factors which cause the errors is a sprue which may deform the framework during solidification and contraction. Purpose: This study was aimed to evaluate objectively effect of the sprue design on the accuracy of fit of implant prosthesis. Materials and method: Three different designs were considered relative to effect of casting accuracy. The first design had straight sprues and a button of excess alloy at the non-casting end of the sprues. The second was runner bar design(with the button). The last was straight sprues design(without the button). Gold cylinder and laboratory analogue had been used to diminish variables affecting to casting accuracy. Gold alloy and pressure-vacuum casting machine had been used. Marginal gap had been measured by SEM. One-way ANOVA and Duncan test had been used for statistical analysis. Results: The first design showed $79.87{\pm}13.95{\mu}m$ marginal gap. The second and third were $40.17{\pm}15.8{\mu}m$ and $35.17{\pm}9.95{\mu}m$ respectively. Conclusion: Straight sprues without button and runner bar designs were more accurate than straight sprues with button design(P<.05).

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.29 no.6
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• pp.444-449
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• 2003

Distraction osteogenesis is a biologic process in which new bone is formed between bone fragments being separated by a tractional force. This technique has the advantage of initiating new bone growth without bone transplantation and promoting the growth of soft tissue. Mandibular distraction osteogenesis has shown to be effective to treat congenital or acquired mandibular hypoplasias. On the basis of positive results with implant-supported prostheses, the use of implants in the distracted site can significantly help stabilize the prosthesis. We obtained good result in the patient with mandibular deficiency due to trauma, who have been reconstructed with distraction osteogenesis and implant. We report our experiences with literature view.

• The Journal of Advanced Prosthodontics
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• v.13 no.3
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• pp.172-179
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• 2021

Purpose. This intra-patient retrospective study of up to 10 years evaluated the clinical success and risk factors of 6- and 8-mm long implants and their respective prostheses. Materials and Methods. The sample consisted of patients treated at a Military Polyclinic dental service, who received both 6- and 8-mm long tissue level implants in the posterior region of the same arch. Data were collected from the dental charts, clinical and radiographic exams, self-report of sleep bruxism, measurement of maximum occlusal force, and clinical crown-to-implant (C/I) ratio. Data were analyzed by descriptive and inferential statistics with univariate and hierarchical multivariate models, at the 0.05 significance level. Results. The 30 patients (27 women) had 85 implants and 83 prostheses. Two implants were lost before prosthesis installation (implant survival: 97.6%). Ten events of prosthetic complication (screw tightening loss) occurred in five patients (success rate: 87.9%) in a single moment. Only the variable C/I ratio had a significant effect for repairable prosthesis complication (P<.05). Conclusion. The results suggest that 6- and 8-mm long implants have similar long-term clinical success for implants and prostheses.