Mechanical Properties of Heat Cured Acrylic Resin Reinforced with Natural Sisal Fibers Powder

Materials and Methods: In total, 90 specimens were prepared to be used in the study. The specimens were divided into (3) main groups depended on the presence of sisal fibers powder, first group (30) specimens of heat cure PMMA without additives (control), second and third experimental groups of 60 specimens of heat cure PMMA with salinized sisal fibers powder with two different weight percentages (1 and 3%) wt. Three point bending test was used to measure the flexural strength of the specimens, while the impact strength was done by impact testing Charpy’s machine and tensile test was performed according to ASTM (D-638). Data analysis was performed using (ANOVA) test. The results of this study refer to a highly significant in the flexural strength and tensile strength of specimens reinforced with sisal fibers powder compared with control specimens. Non-significant difference was detected in impact strength among the reinforced groups and control gro. Reinforcement of acrylic resin with natural sisal fibers powder affects its flexural strength and tensile strength with non-significant in impact strength.

Evaluation Flexural Strength of PMMA Resins with the Addition of Nanoparticles

The flexural strength of heat cure acrylic resin was investigated by adding different concentrations of TiO2 and ZrO2 nanoparticles to increase its mechanical properties. ZrO2 and TiO2 nanoparticles were added at 1, 3, and 5% concentrations to the powder portion of heat polymerized acrylic resins. A total of 49 samples were prepared in 65 × 10 × 3 mm size. The structural characterisations of all experimental groups were determined by Fourier transform infrared spectroscopy. Flexural strength of the resin specimens was evaluated with a three-point bending test in a universal test machine and then examined under by scanning electron microscope to assess its topographic characteristics. The highest flexural strength value was obtained for 3% TiO2, while the lowest values were obtained for 1% and 5% TiO2. 1% ZrO2 and 3% TiO2 groups showed statistically higher flexural strength values than the control group. Addition of 3% and 5% ZrO2 and 1% and 5% TiO2 showed statistically lower flexural strength than the control group.

Rehabilitation of Maxillary Defect Using Zygomatic Implant Retained Obturator

Tumors involving the hard palate, maxillary sinus, or nasal cavity require maxillectomy based on the extent of the lesion. Lack of these boundaries affects the speech, esthetics, and masticatory function. Prosthetic rehabilitation of these defects can be done utilizing zygomatic implants. This present case describes the use of a zygomatic implant to retain a maxillary obturator in a 22-year-old male patient following partial maxillectomy (Brown’s Class 2b) due to odontogenic myxoma. A surgical obturator was secured in position subsequent to the implant placement. Following the healing period, an interim obturator using heat cure acrylic was fabricated. Mechanical retention for the definitive obturator was obtained through the ball attachment suspended from the multiunit abutment of the zygomatic implant. The case was followed up closely for a year to evaluate the function of the prosthesis. The prosthetic rehabilitation not only promoted esthetics and function but also improved the patient’s quality of life.

Influence of Processing Techniques on Microhardness and Impact Strength of Conventional and Reinforced Heat Cured Acrylic Resin: A Comparative Study

This study determined and compared the influences of various processing techniques including air circulating oven (ACO), dry heat oven (DHO) and water bath (WB) on the impact strength (IS) and microhardness (HV) of the conventional heat cure acrylic resin (CHCAR) and rubber reinforced heat cure acrylic resin (RRHCAR). Samples were fabricated using CHCAR (control Group A; n=114) and RRHCAR (experimental Group B; n=114). Group A and B were further divided into subgroups according to processing techniques: ACO, DHO and WB (n=38 each) for both testing variables microhardness and impact strength (n=19 each). Charpy testing machine and Vickers microhardness tester were utilized. Analysis of variance was applied to determine the presence of significant differences among processing techniques while P-value ≤ 0.05 was considered as significant. Water bath (P-value [0.001) and DHO technique (p-value [0.001) showed significant differences between both groups� impact strength and microhardness. Microhardness of group A and B showed a significant difference (p-value 0.002) when processed by ACO. Impact strength and micro hardness were improved in RRHCAR compared to CHCAR processed by ACO and DHO in comparison to WB technique. Rubber reinforced heat cure acrylic resin revealed improvement in the impact strength and microhardness. The air circulating oven exhibited highest microhardness in both testing materials. Dry heat oven showed improved values of impact strength in conventional heat cure acrylic resin.

Effect of mechanical and chemical surface treatment on bond strength of acrylic denture teeth to heat cure acrylic resin-an invitro study

Debonding of denture teeth from the denture base has posed a great problem to the clinician and patient. Chemical and mechanical treatments have been performed separately, but there are no studies performed using the combination of chemical and mechanical surface treatments. This study aims at evaluating and comparing the bond strength by using chemical and mechanical surface treatments.60 maxillary right central incisor teeth were used in 5 groups for surface treatment on the ridge lap area: 1 untreated, 2-sandblasting, group 3- Heat cure monomer, 4- sandblasting+ monomer, 5- Dichloromethane. The acrylic teeth were attached to a wax block at an angle of 45º. These were flasked and dewaxed, followed by surface treatment and acrylisation. All cured specimens were loaded under a universal testing machine on the palatal surface at a cross head speed of 1mm/min till fracture occurred. Data obtained was statistically evaluated by one way ANOVA. Surface treatment with dichloromethane showed the highest bond strength of acrylic teeth to heat cure denture base when compared with sandblasting and monomer application. On visual analysis of the fractured specimens, maximum amount of cohesive failures were noticed in the dichloromethane group.Dicholoromethane can be used as an effective and quick method to improve the bonding of acrylic teeth to denture base.

Influence of Different Reline Materials and Processing Methods on Flexural Strength of Denture Base Material

Summary Background/Aim: Relining is defined as the procedure used to resurface the tissue side of a denture with new base material, thus producing an accurate adaptation is provided at the denture foundation area. During mastication, relined dentures have to withstand masticatory forces to prevent fracture. The aim of this study was to evaluate the flexural strength of acrylic resin denture base relined with different methods and materials. Material and Methods: Fourteen experimental groups and one control group were determined to consider different reline materials and processing methods. Acrylic resin specimens were prepared with the dimensions of 65× 10× 1.5 mm and reline materials (1.5 mm thickness) were placed on acrylic resins. Reline material was not used in control group specimens. Flexural strength values of relined and control specimens were measured with three-point bending test at a speed of 5 mm/min. Data were analyzed with using one way Anova and Student t tests. Results: The highest flexural strength values were shown in control group (86.51±1.08 MPa). There were significant differences among relined specimens (p< 0.05). For the relined specimens, the highest flexural strength values were found in the relined specimens with denture base material (77.90±1.93 MPa), and the lowest values were found in relined with autopolymerize acrylic material (59.81±1.50 MPa). Conclusions: Relining of the heat cure denture base material significantly decreases the flexural strength for all processing methods and materials.

PREPARATION FOR PALATOPLASTY SURGERY WITH AN ACRYLIC FEEDING OBTURATOR: A CASE REPORT

ABSTRACTBackground: Clefts on the lips and palate are common cases to be found frequently in the field of dentistry. This gap connects the oral cavity and the nasal cavity so that it interferes with the nutritional intake in patients. The age and size of the oral cavity in patients become particular challenges for prosthetic rehabilitation. Another challenge lies at the impression procedure, because it is an essential part in the making of obturator. Objective: To provide information on the management of patient with cleft palate using feeding obturator from acrylic material. Case: A 13-months-old male patient arrived at Prof. Soedomo Gadjah Mada University Dental Hospital with his parents and was seeking for prosthetic therapy to cover the cleft on his palate because it had been muddling with food and beverage intake. Patient had undergone cheiloplasty surgery and further arranged for palatoplasty procedure. Intraoral examination exhibited a cleft extended from hard palate, soft palate, and uvula. Case management: Upper jaw impression was performed for individual tray fabrication, followed by impression procedure in an upright straight position until the patient bawled. The impression result was casted to construct an obturator using acrylic heat cure material. Fitting surface was covered with soft liner. Treatment result showed that the obturator was retentive, stable and able to assist the nutritional intake in patient. Conclusion: Acrylic feeding obturator can recover the condition in patient with cleft palate and improve nutritional intake as well as body weight to prepare patient for palatoplasty surgery.Keywords: Cleft Palate, Feeding Plate, Obturator