A Synopsis
ON
THE EFFECT OF FIBER GLASS AND ARAMID FIBRE REINFORCEMENT ON THE FLEXUREAL STRENGTH OF PROVISIONAL RESTORATIVE RESINS
BY
DR. ZARIR BAGHERI
POST GRADUATE STUDENT
DEPARTMENT OF PROSTHODONTICS
BANGALORE INSTITUTE OF DENTAL SCIENCES AND HOSPITAL
BANGALORE
RAJIV GANDHI UNIVERSITY OF HEALTHSCIENCES,
KARNATAKA, BANGALORE
ANNEXURE-II
PROFOMA FOR THE REGISTRATION
OF SUBJECT FOR DISSERTATION
1 / NAME OF THE CANDIDATE AND ADDRESS / Dr. ZARIR BAGHERIDEPARTMENT OF PROSTHODONTICS
BANGALORE INSTITUTE OF DENTAL SCIENCES AND HOSPITAL.
BANGALORE-560029
2 / NAME OF THE INSTITUTION / BANGALORE INSTITUTE OF DENTAL SCIENCE AND POST GRADUATE RESEARCH CENTER, BANGALORE-29.
3 / COURSE OF STUDY AND SUBJECT / MASTER OF DENTAL SURGERY
PROSTHODONTICS
4 / DATE OF ADMISSION TO COURSE / 2ND JUNE 2008
5 / TITLE OF THE TOPIC / THE EFFECT OF FIBER GLASS AND ARAMID FIBRE REINFORCEMENT ON THE FLEXUREAL STRENGTH OF PROVISIONAL RESTORATIVE RESINS
6 / BRIEF RESUME OF THE INTENDED WORK
6.1 NEED FOR THE STUDY
Provisional crowns and fixed partial dentures (FPDs) are essential components of fixed prosthodontic treatment. Provisional restorations must satisfy biologic and esthetic needs as well as mechanical requirements such as resistance to functional loads, resistance to removal forces, and maintenance of abutment alignment. Strength of a material can be a determinant of how well these requirements are met. Flexural strength, also known as transverse strength, is a measurement of the strength of a bar (supported at each end) under a static load. The flexural strength test is a combination of tensile and compressive strength tests and includes elements of proportional limit and elastic modulus measurements. The flexural strength of provisional materials is important, particularly when the patient must use the provisional restoration for an extended period, when the patient exhibits parafunctional habits, or when a long-span prosthesis is planned. Presently, there is no provisional material that meets optimal requirements for all situations. Clinicians typically choose a product based on ease of manipulation, cost, and esthetics. . Various type of fibers used for reinforcement such as glass-carbon, aramid and polyethylene fibers have been investigated. In this study, the flexural strength of four types of provisional restoration materials (Poly methylmethacrylate-selfcure, Poly methylmethacrylate-heatcure, Poly ethylmethacrylate and Bisacryl composite) reinforced with fiber glass and aramid will be determined.
6.2 REVIEW OF LITERATURE
1. This study¹ determined the load required to fracture a three-unit provisional fixed partial denture restoration, which had been reinforced with experimental glass fiber reinforcement. Five groups of provisional fixed partial dentures were fabricated from a resin of polyethyl methacrylate powder and n-butylmethacrylate liquid. The control Group fixed partial dentures were not reinforced. In the other groups, the fixed partial dentures were reinforced with either one, two or three unidirectional glass fiber reinforcements and one glass fiber weave reinforcement. The loading test was then done by a steel ball placed in the cavity in the Middle fossa of the pontic tooth. The results of this study suggest that even though the glass fiber reinforcement were positioned on the least favourable side of the fixed partial dentures in terms of the physical properties of the materials, these reinforcements considerably increased the fracture resistance of provisional fixed partial dentures.
2. This study² determined whether the flexural strength of a commercially available, heat-polymerized acrylic denture base material could be improved through reinforcement with 3 types of fibers. Ten specimens of similar dimensions were prepared for each of the 4 experimental groups: Conventional acrylic resin and the same resin reinforced with glass, aramid, or nylon fibers. Flexural strength was evaluated with a 3-point bending test. This study concluded that the flexural strength of heat- polymerized PMMA denture resin was improved after reinforcement with glass or aramid fiber.
3. This study³ compared the flexural strength of 5 methacrylate-based resins and 8 bis-acryl resins used to fabricate provisional crowns and fixed partial dentures. Ten bar- types specimens were fabricated according to American national standard Institute / American dental association specification 27 for each material with the use of split machined aluminium mold sandwiched between 2 glass slabs. After being immersed in artificial saliva at 37º C for 10 days, the specimens were fractured under 3- point loading in a universal testing machine at a crosshead speed of 0.75mm/min. Maximal loads to fracture in Newtons were recorded. This study concluded that the flexural strengths were material- rather than category-specific. Some but not all bis-acryl resins demonstrated significantly superior flexural strength over traditional methacrylate resins.
4. This study4determined the fracture toughness and flexural strength of different types of provisional restoration resins reinforced with different commercially available fibers, A total of 105 specimens were prepared in this study for each test; compact tensile specimens for the fracture toughness test and rectangular specimens for the flexural test. The specimens were divided into 3 groups according to the type of resin used, jet, Trim, or Temphase (n=35), and then each groups was divided into 7 subgroups (n=5) according to the type of fiber reinforcement, Construct, fibrestick ribbond normal, ribbond THM, ribbond traixial, or fibrent. Unreinforced specimens served as the control specimens were loaded in a universal testing machine until fracture. This study concluded that the addition of the fibers to the provisional resin increased both fracture toughness and flexural strength.
5. This study5 determined whether the fiber reinforcement improved the flexural strength of an indirect composite resin aged in air and water. The materials tested in this study, non-fiber reinforced composite resin (n= 160) (Tescere Dentine) and fiber-reinforced composite resin (n=160) ( Tescere U-beam and rod), were fabricated as bars, 25.0 x 4.5 x 4.5 mm, and polished with 120- to 320- grit silicon carbide grinding paper. The static (n=15) and cyclical (n=25) flexural strengths (MPa) of specimens were tested initially and after 3 months of aging in air and water. The specimens were tested in 3- point loading in their respective aging media at a loading rate of 2 mm/min. Cyclic testing followed the staircase approach of either 1000 cycles or until spacemen fractures. This study concluded that, when compared to indirect composite resin without fiber reinforcement, the addition of fibers is an effective method to improve the flexural strength of indirect composite resin for the materials tested.
6. This study6 compared the fracture toughness of a polymethyl methacrylate (PMMA) resin and a bis-acryl composite (BAC) resin reinforced with stainless steel wire, glass fiber and polyethylene fiber. Four groups (n=13) of each of the 2 materials were prepared for the single-edge notch 3- point-bending test. Three groups had the different reinforcements, and the group without reinforcement served as the control. Using a universal testing machine, peak load to facture was recorded and fracture thoughness (KIC) was calculated in MNm-1.5. This study concluded that of the 3 reinforcement methods evaluated, wire and glass fiber reinforced the PMMA and BAC resin materials best.
6.3 OBJECTIVES OF THE STUDY
1. To evaluate the flexural strength of four different materials used for fixed provisional restorations.
2. To study the effect of different reinforcement materials (glass fiber and aramid) on the flexural strength of four different materials used for fixed provisional restorations.
7. / MATERIALS & METHODS
7.1 SOURCES OF DATA
1. Polymethyl methacrylate ( P.M.M A) Heat cure D.P.I ( India )
2. Polymethyl methacrylate ( P.M.M A) self cure D.P.I ( India )
3. Polyethyl methacrylate (P.E.M.A) self cure Acropars T.R.IDS ( India )
4. Bisacryl composite (B.A.C) Protemp 3 ( Germany )
5. Fiber Glass C.S.M Vitrodox ( India )
6. Aramid Kevlar ( India)
7. 2 METHOD OF COLLECTION OF DATA
1. 120 samples using standardized mold and four different types of provisional restorative resins will be made. These samples are tested in the universal testing machines for flexural strength using 3 point bending test. This data is obtained.
PREPARATION OF SAMPLES
1. A stainless steel rectangular mold of dimension 25 x 5 x 3mm is made.
2. 120 samples are divided into 4 main groups: Group A (PMMA self cure), group B (PMMA heat cure), group C (PEMA self cure), group D (Bisacryl composite). Each of these 4 group are further divided into 3 subgroups: Subgroups I control, sub group II Fiber glass reinforcement, and subgroup III aramid reinforcement, each containing 10 samples.
3. The reinforcement fibers have a thickness of 5-10 u/m and are cut into 5mm long fibers.
4. These fibers are placed in monomer for 10 minutes to aid in better bonding with acrylic resin.
5. The resin is mixed according to manufacturer’s instructions to which 2% of fiber is added.
6. The reinforced resin is packed in dough stage into the mold.
7. After polymerization samples were stored in water for 1 week at the room temperature before testing.
8. The Samples are tested in the universal testing machine for flexural strength using 3 point bending test.
7.3 Does the study require any investigation or intervention to be conducted on the patient or other animals?
Not applicable
7.4 Has ethical clearance been obtained from our institution?
Not applicable
8. / LIST OF REFERENCES
1. P.K Vallittu. The effect of glass fiber reinforcement on the fracture resistance of a
provisional fixed partial denture. J prosthetic dentistry 1998; 79: 125-130.
2. Jacob john, Shivaputrappa A. Gangadhar: Flexural strength of heat-polymerized
polymethyl methacrylate denture resin reinforced with glass, aramid, or nylon fibers
J. Prosthetic dentistry 2001; 86:424-7.
3. Debra R. Haselton, Ana M.Diaz-Arnold and Marcos A. Vargas. Flexural strength of provisional crown and fixed partial denture resins J. Prosthetic dentistry
2002;87:225-8.
4. Tamer A. Hamza, Stephen F. RosentielMohamed M. Elhosary and Rabab M.
Ibraheem. The effect of fiber reinforcement on the fractural toughess and flexural strength of provisional restorative resins. J. Prosthetic dentistry 2004;91:258-64.
5. Mohammed Al-Darwish Ryan K. Hurley James L. Drummond. Flexural strength evaluation of a laboratory- processed fiber-reinforced composite resin. J. Prosthetic dentistry. 2007;97:266-70.
6. Greta A.V.M Greets, Jan-Hendrik Overturf and Theuns G. Oberholzer. The
effect of different reinforcements on the fracture toughness of materials for interm
restorations. J. Prosthetic dentistry. 2008;99:461-467.
9 / Signature of the Candidate / Dr. Zarir Bagheri
10 / Remarks of the Guide
11 / 11.1 Guide
11.2 Signature / Dr. Soorya Poduval
Professor
Dept of Prosthodontics
Bangalore Institute of Dental Sciences
Bangalore.
11.3 Co-Guide
11.4 Signature
11.5 Head of the department
11.6 Signature / Dr. G.R. Rahul
Professor & Head
Dept of Prosthodontics
Bangalore Institute of Dental Sciences
Bangalore.
12 / 12.1 Remarks of the
Chairman and Principal
12.2 Signature
8