RAJIV GANDHI UNIVERSITY OF HEALTH SCIENCES, KARNATAKA
BANGALORE
ANNEXURE - II
PROFORMA FOR REGISTRATION OF SUBJECTS FOR DISSERTATION
1. / Name of the Candidate &Address
(In block letters)
Permanent Address / DR. SUBASHANI
POST GRADUATE STUDENT,
A.M.E`S DENTAL COLLEGE, HOSPITAL AND RESEARCH CENTRE,
DEPARTMENT OF PROSTHODONTIA,
BEJENGERE ROAD,
RAICHUR,
KARNATAKA-584103
7-5-246 JAWAHARNAGAR
RAICHUR.-584103
2. / Name of the Institution / A.M.E`S DENTAL COLLEGE, HOSPITAL AND RESEARCH CENTRE,
RAICHUR,
KARNATAKA-584103
3. / Course of study and
subject / MASTER OF DENTAL SURGERY (MDS) IN PROSTHODONTIA.
4. / Date of admission to
Course / 30-05-2013
5. / Title of the Topic / INFLUENCE OF CUSPAL INCLINATION AND ALTERED OCCLUSION OF CERAMIC CROWN ON STRESS DISTRIBUTION AROUND BASAL AND CRESTAL OSSEOINTEGRATED IMPLANT IN MANDIBULAR FIRST MOLAR REGION – A FINITE ELEMENT STUDY.
6. / Brief resume of the intended work
6.1 Need for the study
The successful, long term clinical use of dental endosseous implants requires restorations that have a predictable prognosis, minimal biological trauma and at reasonable cost.Dental implants present different biological and biomechanical characteristics than natural teeth. Occlusion is considered to be one of the most important factors contributing to implant success.1
Occlusal configuration and cuspal inclination of implant-supported prosthesis play a significant role in force transmission and the stress –strain relationship between the prosthesis and bone.2Too much stresses can lead to bone resorption, which eventually causes loosening of the implant.3
For Crestal and basal implants substantial differences lie in the planning and execution of prosthodontic care, and most of all, in the post-insertion treatment regime. Crestal and basal implants are endosseous aids to create osseointegrated points of retention. These two types of implants are not only differentiated by the way they are inserted but also by the way the forces are transmitted.4
Finite element analysis has been used extensively to predict the biomechanical performance of various dental implant designs as well as the effect of clinical factors on implant success. A key factor for the success or failure of a dental implant is the manner in which stresses are transferred to the surrounding bone.5
Since the first molars are the first permanent teeth to erupt in the mouth and often play a pivotal role in the maintenance of the arch form and proper occlusal schemes and also these teeth are often the first to decay, the tooth is at risk of extraction and hence is a leading cause of single posterior tooth loss in adult.6 There are also no literature comparing effect of stress on implant and its surrounding bone between crestal and basal implants with altered occlusion.
So the need for this study is to assess the influence of cuspal inclination and altered occlusion on the distribution of stresses in the Osseo integrated basal and crestal implants using finite element analysis in the mandibular 1st molar region.
6.2 Review of literature:
A comparative study on basal and crestal implants discussed the value of using basal implants and differences that exist between basal and crestal implants in perioperative status, infection around integrated implants, load transmission and replacement of failing implants.4
In a comparative study between one and two Branemark implants replacing a single molar, it was found logical to use the slightly wider 4mm diameter implants for posterior region. It was demonstrated that the single implant, single molar restoration is a possible alternative; it appears that the use of two implants provides distinct biomechanical advantages but the drawback is the need for minimum 12mm of space to accommodate two implants.7
An in-vitro study on finite element analysis to model bone-implant contact with basal implant was conducted. The model was applied to the biological scenario of changing load distribution in a basal implant system over time. It was concluded that in case of hard contact, the peak stresses occur above the contact surface whereas in soft contact, the stress peak occurs in the upper part of the contact area between the bone and vertical shaft of the implant.8
A study was done to compare simulated bone strains of implant-supported second premolar crowns under controlled experimental conditions with four occlusal designs. It was concluded that a reduced cusp inclination and occlusal table dimension effectively reduced bone strain on implant-supported single crowns in the laboratory model.9
A study was done to provide a preliminary understanding of the biomechanics with respect to the effect of cusp inclination and occlusal loading on the mandibular bone remodelling.It was concluded that the dental implant superstructure design (in terms of cusp inclination and loading location) determines the load transmission pattern and thus largely affects bone remodeling activities. Although the design with a lower cusp inclination recommended in previous studies may reduce damage and fracture failure, it could, to a certain extent, compromise bone engagement and long term stability.10
6.3 Objectives of the study
1. To evaluate and compare the distribution of stresses in two Osseo integrated crestal implants supporting two crowns and a basally Osseo integrated implant in mandibular 1st molar region with cuspal inclination of 30o, 20o and 10o.
2. To evaluate and compare the distribution of stresses in two Osseo integrated crestal implants supporting two crowns and a basally Osseo integrated implant in mandibular 1st molar region with cuspal inclination of 30o, 20o and 10o when occlusion is altered.
3. To identify the preferable implant option for better stress distribution in mandibular 1st molar region.
7 / MATERIAL AND METHODS
7.1 Source of Data:
A three dimensional Finite Element Analysis computer software (ANSYS) will be used to develop a model of the missing 1st molar region of mandibular bone with an two osseointegrated crestal implants with crowns and basally osseointegrated implant-supported crown.
7.2 Methods of collection of data
A bone block, representing the section of the mandible in first molar region will be modeled with basal and crestal implants. Crown superstructure will be prepared on the model with different cuspal inclinations and altered occlusion. Load will be applied on software generated osseointegrated crestal and basally osseointegrated implant-supported crown models and the resulting Von Mises stresses in the bone model will be assessed.
7.3 Does the study require any investigation or intervention to be conducted on patients or other humans or animals? If so please describe briefly.
NO
7.4 Has ethical clearance has been obtained from your institution in case of 7.3?
NO
8. / LIST OF REFERENCES:
1. Yuan JC, Sukotjo C.Occlusion for implant-supported fixed dental prostheses in partially edentulous patients: a literature review and current concepts. J Periodontal Implant Sci 2013;43:51-57.
2. Falcon-Antenucci RM, Piza E, Pellizzer, Perri de carvalho PS, Goiato CM, Noritomi YP. Influence of cusp inclination on stress distribution in implant-supported prostheses. A three dimensional finite element analysis. Journal of Prosthodontics 2010;19: 381-386.
3. Meijer HJA, Kuiper JH, Starmans FJM, Bosman F. Stress distribution around dental implants: influence of superstructure, length of implants and height of mandible. J Prosthet Dent 1992;68:96-102.
4. Ihde S, Dent M. Comparison of basal and crestal implants and their modus of application. Smile Dental Journal 2009;4(1):36-46.
5. Geng J, Tan KBC, Liu GR. Application of finite element analysis in implant dentistry: A review of the literature. J Prosthet Dent 2001;85:585-98.
6. Misch CE. Contemporary implant dentistry.3rd ed. Elsevier Mosby 2008 Page no 327.
7. Balshi TJ, Hernandez RE, Pryszlak MC, Rangert B. A comparative study of one implant versus two replacing a single molar. Int J Oral Maxillofacial Implants 1996;11:372-78.
8. Ihde S, Dent M, Goldmann T, Himmlova L, Aleksic Z. The use of finite element analysis to model bone-implant contact Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2008;106:39-48.
9. Rungsiyakull P, Rungsiyakull C, Appleyard R, Swain M, Klineberg I. Loading of a single implant in simulated bone.Int J Prosthodont 2011;24:140-143.
10. Rungsiyakull C, RungsiyakuII P, Li Q, Li W. Effects of occlusal inclination and loading on mandibular bone remodeling:A finite element study.Int J Oral Maxillofacial Implants 2011;26:527-537.