• Title/Summary/Keyword: double tooth

Search Result 100, Processing Time 0.025 seconds

Rational designing of double-sided nail plate joints using the finite element method

  • Zhou, Tinozivashe;Guan, Z.W.
    • Structural Engineering and Mechanics
    • /
    • v.28 no.2
    • /
    • pp.239-257
    • /
    • 2008
  • Double-sided punched metal plate timber fasteners present projections on both sides, which offer improved joint fire resistance and better joint aesthetics. In this paper, 3-D nonlinear finite element models were developed to simulate double-sided nail plate fastener timber joints. The models, incorporating orthotropic elasticity, Hill's yield criterion and elasto-plasticity and contact algorithms, are capable of simulating complex contact between the tooth and the timber and between the base plate and the timber in a fastener. Using validated models, parametric studies of the double-sided nail plate joints was undertaken to cover the tooth length and the tooth width. Optimal configuration was assumed to have been attained when increase in nail plate tooth width did not result in a raise in joint capacity, in conjunction with the optimum tooth length. This paper presents the first attempt to model and optimise tooth profile of double-sided nail plate fastener timber joints, which offers rational designs of such fasteners.

Effect of splinting on abutment tooth movement when a distal extension partial denture used(II) (유리단국부의치(遊離端局部義齒) 사용시(使用時) 지태치(支台齒) 동요(動搖)에 대한 Splingting의 효과(效果)(II))

  • Jung, Jong-Hyun
    • Journal of Technologic Dentistry
    • /
    • v.8 no.1
    • /
    • pp.85-90
    • /
    • 1986
  • The effect of splinting on aqbutment tooth distal movement was performed in vitro study. An acrylic resin mandibular model with missing 2nd premolars, molars and a removable partial denture framework were constructed. The roots of the canines, 1st premolars and edentulous ridges were coated with silicone rubber. A modified Ney Surveyor was used for vertical load appkication, and abutment tooth distal movement were measured with a dial gauge with four conditions of splinting methods were tested by applying unilateral vertical loadings. The results are follows; 1. The magnitude of abutment tooth distal movement on the non-load side was less 40$\sim$69% than that occurred on the load side. 2. On the load side, reducing effect of splinting on abutment tooth movement in the condition of load side double abutment(30%), non-load side double abutment(10%), double abutments of both sides(40%) was compared with single abutments of both sides. 3. On the non-load side, reducing effect of splinting on abutment tooth movement in the condition of load side double abutment(5%), non-load side double abutment(22%), double abutments of both sides(59%) was compared with single abutments of both sides. 4. The magnitude of abutment tooth distal movement in the condition of double abutments of both sides was less 40$\sim$59% than that in the condition of single abutments of both sides.

  • PDF

TREATMENT OF DOUBLE TOOTH IN MANDIBULAR LATERAL INCISORS (하악 영구 측절치 Double tooth의 치험례)

  • Kim, Sang-Bae;Lee, Kwang-Soo
    • Journal of the korean academy of Pediatric Dentistry
    • /
    • v.27 no.3
    • /
    • pp.383-387
    • /
    • 2000
  • Fusion is defined as union of two separate tooth buds at some stage in their development with confluence of dentin and characterized by separate root canal and large single crown, while gemination is defined as an attempt of the single tooth bud to incompletely divide and usually result in a single root with one root canal and two completely or incompletely separated crowns. It is sometimes difficult to decide whether an abnormally large tooth is the result of fusion of a normal and a supernumerary tooth, or of gemination; use of the term 'Double tooth' may make the clinicians avoid this difficulty(Brook & Winter). Commonly there are no symptoms, but the problems associated with these anomalies include esthetics, possible loss of arch length and delayed or ectopic eruption of the permanent teeth, caries along the line of demarcation, and periodontal disease. Commonly, it dose not need to be treated in primary dentition but in case of permanent dentition, it may be requested to be treated due to esthetics and other problems. In our case, a 8 years old girl showed a Double tooth, we attained the favorable results by performing hemisection with apexification.

  • PDF

Dentigerous Cyst with Double Teeth in a Dog

  • Park, Sang-hun;Park, Hyunjung;Yun, Youngmin;Cheong, Jongtae
    • Journal of Veterinary Clinics
    • /
    • v.39 no.1
    • /
    • pp.23-27
    • /
    • 2022
  • An 11-year-old spayed female Maltese dog presented with mass in oral cavity. On conscious oral examination, the right maxillary canine tooth was not visible, and a lesion has been suspected of mass existed in canine tooth area. The adjacent maxillary first premolar was buried in the lesion, with a little part of the tooth exceptions. On radiographic examination, the canine tooth was buried horizontally in the lesion, and the root part was adjacent to the first premolar tooth. Extraction was performed for a treatment. When the lesion was incised, the canine tooth was horizontal with the concave surface facing the palatal, and formed double teeth by fusing with the premolar tooth at the roots parts of the teeth. This report described the double teeth in the dentigerous cyst rarely reported in dogs.

Mandibular lateral incisor with four root canals: A unique case of double tooth diagnosed using multidetector computed tomography

  • Gupta, Sunil Kumar;Gupta, Jaya;Acharya, Shashi Rashmi;Ather, Amber
    • Imaging Science in Dentistry
    • /
    • v.43 no.2
    • /
    • pp.123-128
    • /
    • 2013
  • Double tooth is a dental anomaly consequent to fusion of two or more teeth or gemination of a single tooth. This report describes a unique case of double tooth in relation to a mandibular lateral incisor exhibiting the presence of four root canals. The role of conventional radiography and advanced three-dimensional imaging techniques in the better assessment of complex root canal systems and their aid in endodontic management has also been highlighted.

Clinical outcomes of rigid and non-rigid telescopic double-crown-retained removable dental prostheses: An analytical review

  • Seo, Jeong-Gyo;Cho, Jin-Hyun
    • The Journal of Advanced Prosthodontics
    • /
    • v.12 no.1
    • /
    • pp.38-48
    • /
    • 2020
  • PURPOSE. The objective of this literature review was to analyze the cumulative survival rates (CSRs) of rigid and non-rigid double-crown-retained removable dental prostheses. MATERIALS AND METHODS. Screening of the literature published from January 1995 to December 2019 was performed by using electronic data base (Pubmed) and manual search. The CSRs of rigid and non-rigid double crown removable dental prostheses were investigated. RESULTS. A total of 403 articles were reviewed and 56 relevant articles of them were selected. Subsequently, 25 articles were included for data extraction. These articles were classified according to rigid and non-rigid type double crowns and further subdivided into teeth, implants, and teeth-implant combination types. The CSRs of rigid type double crown ranged from 68.9% to 95.1% of 5 to 10 years in tooth abutments, 94.02% to 100% over a 3-year mean observation periods in implant abutments, and 81.8% to 97.6% in tooth-implant combination. Non-rigid type double crowns had various CSR ranges from 34% to 94% maximum during 10 years observation in teeth abutment. The CSRs of non-rigid type had over 98% in implant abutments, and ranged from 85% to 100% in tooth-implant combination. CONCLUSION. The CSRs of double crowns varies according to types. With accurate evaluation of the remaining teeth and plan of the strategic implant placement, it could be successful treatment alternatives for partially or completely edentulous patients.

Causes of failures of long-term used double crown denture and new rehabilitation with dental implant and tooth combined denture using remaining teeth and implants (장기간 사용한 이중관 의치의 실패원인 및 자연치와 임플란트를 이용한 이중관 의치 수복증례)

  • Seo, Jeong-Gyo;Cho, Jin-Hyun
    • The Journal of Korean Academy of Prosthodontics
    • /
    • v.56 no.4
    • /
    • pp.384-390
    • /
    • 2018
  • Hybrid telescopic double crown have ever been good treatment option for patient with periodontally unfavorable few remaining teeth for successful prognosis. Tooth and implant combined telescopic double crown can be used for improving retention and support for denture with strategically placed implants on edentulous ridge. In this case, an 55-year-old female patient had chronic periodontitis with few remaining teeth on maxilla and fixed partial prosthodontics on mandible. Treatment of hybrid telescopic double crown with friction pin lasted 9.5 years only with natural teeth. After 9.5 years, additional implants was installed due to fracture of cast-posted abutment teeth. After implantation, tooth and implant combined double crown had fabricated. Through re-treatment, no complications of new denture has been found during 2 years follow up. This case presents fair prognosis of tooth and implant combined double crown denture in periodontally unfavorable condition.

Guided endodontics: a case report of maxillary lateral incisors with multiple dens invaginatus

  • Ali, Afzal;Arslan, Hakan
    • Restorative Dentistry and Endodontics
    • /
    • v.44 no.4
    • /
    • pp.38.1-38.8
    • /
    • 2019
  • Navigation of the main root canal and dealing with a dens invaginatus (DI) is a challenging task in clinical practice. Recently, the guided endodontics technique has become an alternative method for accessing root canals, surgical cavities, and calcified root canals without causing iatrogenic damage to tissue. In this case report, the use of the guided endodontics technique for two maxillary lateral incisors with multiple DIs is described. A 16-year-old female patient was referred with the chief complaint of pain and discoloured upper front teeth. Based on clinical and radiographic findings, a diagnosis of pulp necrosis and chronic periapical abscess associated with double DI (Oehler's type II) was established for the upper left lateral maxillary incisor (tooth #22). Root canal treatment and the sealing of double DI with mineral trioxide aggregate was planned for tooth #22. For tooth #12 (Oehler's type II), preventive sealing of the DI was planned. Minimally invasive access to the double DI and the main root canal of tooth #22, and to the DI of tooth #12, was achieved using the guided endodontics technique. This technique can be a valuable tool because it reduces chair-time and, more importantly, the risk of iatrogenic damage to the tooth structure.

Finite element generalized tooth contact analysis of double circular arc helical gears

  • Qu, Wentao;Peng, Xiongqi;Zhao, Ning;Guo, Hui
    • Structural Engineering and Mechanics
    • /
    • v.43 no.4
    • /
    • pp.439-448
    • /
    • 2012
  • This paper investigates the load sharing of double circular arc helical gears considering the influence of assembly errors. Based on a load sharing formulae, a three-dimensional finite element tooth contact analysis (TCA) is implemented with commercial software package ANSYS. The finite element grid for the double circular arc gear contact model is automatically generated by using the APDL (ANSYS Parameter Design Language) embedded in ANSYS. The realistic rotation of gears is achieved by using a coupling degree-of-freedom method. Numerical simulations are carried out to exemplify the proposed approach. The distribution of contact stress and bending stress under specific loading conditions are computed and compared with those obtained from Hertz contact theory and empirical formulae to demonstrate the efficiency of the proposed load sharing calculation formulae and TCA approach.