Effectiveness of denture cleansers on flexible denture base resins in the removal of stains colored by food colorant solution: An in vitro study.

Aim: The aim of the study was to compare the efficiency of three denture cleansers (Valclean, Polident and Clinsodent) in removal of turmeric stains from flexible denture base resins. Settings and Design: In vitro - comparative study. Materials and Methods: A total of 45 specimens of flexible denture base resins were fabricated and subjected to baseline colour measurements using spectrophotometer. Specimens were stained with turmeric and colour measurements of stained specimens were made. All the stained specimens were divided into three groups (n = 15) for removal of stains with three denture cleansers: Valclean, Polident, Clinsodent and colour measurements of cleansed specimens were made. The colour measurements (ΔE) values obtained were collected and statistical analysis was done. Statistical Analysis Used: One-way ANOVA (Analysis of Variance), Tukey's post hoc test. Results: One way ANOVA test revealed that the mean colour difference of three groups were statistically different with P value < 0.001. A further Tukey post hoc test revealed that the Valclean group had lesser mean scores than Polident and Clinsodent group. Conclusion: It was concluded that Valclean showed statistically significant greater stain removal efficiency than Polident followed by Clinsodent.

Comparative evaluation of enamel wear against monolithic zirconia and layered zirconia after polishing and glazing: An in vitro study.

Aim: The aim of this study was to compare the wear behavior of human tooth enamel opposing monolithic zirconia and layered zirconia after glazing and polishing by a two-body wear mechanism using a wear simulator. Settings and Design: This In-vitro study was done in Department of Prosthodontics, Sri Sai College of Dental Research, Vikarabad. Materials and Methods: Zirconia specimens were divided into four groups (n = 15), Group monolithic glazed zirconia (MG), Group monolithic polished zirconia (MP), Group zirconia layered with E. max ceram and glazed (LG), Group zirconia layered with E. max ceram and polished without glaze (LP). Sixty human premolar teeth were subjected to wear test against the zirconia specimens using a Pin on Disc wear tester under a constant load of 5 kg (49 N) at 30 rpm for 10,000 cycles. The loss of enamel was recorded before and after the wear test and mean loss of height of tooth enamel after 10,000 cycles of wear was measured with a profile projector. The surface characteristics of all the four group zirconia specimens were evaluated qualitatively with scanning electron microscope. Statistical Analysis Used: One way ANOVA, Tukey Post hoc. Results: One-way analysis of variance test revealed that the mean loss of enamel of four groups was statistically different with P < 0.001. A further Tukey post hoc test revealed that the MP group had lesser mean scores than group LP, MG, and LG. Conclusion: It was concluded that MP caused less wear to opposing natural teeth, and polished surfaces of both monolithic and layered zirconia showed less tooth wear compared to glazed surfaces of monolithic and layered zirconia.

Evaluation of flexural strength of Zirconia using three different connector designs: An in vitro study.

AIM: The aim of this study is to evaluate the flexural strength of zirconia using three different connector designs under vertical and oblique loads. SETTING AND DESIGN: Invitro - analytical study. MATERIALS AND METHODS: For simulating zirconia fixed partial prosthesis, a specimen with three octagonal cylinders connected with each other was designed. Each face of the octagon was 3.75 mm ± 0.1 mm, and the total width was 9 mm ± 0.1 mm with a standard connector area of 10 mm2 at cross-section. Three different connector designs, i.e., round, oval, and triangular were milled. Universal testing machine was used to test flexural strength with vertical and oblique forces. STATISTICAL ANALYSIS USED: Intergroup comparison of flexural strength was made using Descriptive statistics (1) one-way ANOVA, Bonferroni's post hoc test (2) Kruskal-Wallis test. The confidence interval was set at 95%, P < 0.05 was considered statistically significant for both the tests. RESULTS: The highest flexural strength was observed in the triangle connector with vertical forces and lowest with oblique forces. CONCLUSIONS: Triangle connector design proved to be better than round and oval connectors on the application of vertical loads. Round connector design proved to be better than triangle and oval connector on application of oblique loads.

An In vitro Study to Evaluate the Effect of Eugenol-free and Eugenol-containing Temporary Cements on the Bond Strength of Resin Cement and Considering Time as a Factor.

AIMS AND OBJECTIVES: The aim of this study was to assess the outcome of eugenol-free and eugenol-containing cements on the bond strength of resin cement. MATERIALS AND METHODS: Dentin was exposed in five groups of extracted teeth (20 specimens each). In Group 1, specimens were not given temporary cementation. In Groups 2 and 3, specimens were given temporary restoration fixed with eugenol-free temporary cement for 7 and 14 days, respectively. In Groups 4 and 5, specimens were given temporary restoration fixed with eugenol-containing temporary cement for 7 and 14 days, respectively. Permanent cementation was done for all groups after specified period of time. Shear bond strength testing of specimens was carried under universal testing machine. The data were analyzed by SPSS for Windows (version 14) statistical package (SPSS Inc., Chicago, IL, USA). RESULTS: One-way analysis of variance test revealed that Group 1 specimens produced higher shear bond strength than Groups 2, 3, 4, 5 and the difference was statistically significant (P < 0.001). In Groups 2, 3, 4, and 5, no significant difference in shear bond strength was observed between provisional restoration with eugenol-containing zinc oxide cement and provisional restoration with eugenol-free zinc oxide cement (P = 0.095). CONCLUSION: The findings of this in vitro experiment lend no support to the common opinion that eugenol-containing cements should be avoided as temporary cement.

Evaluating the fracture toughness and flexural strength of pressable dental ceramics: an in vitro study.

The study was undertaken to evaluate the biaxial flexural strength, biaxial flexural strength after etching with 9 % HF acid and fracture toughness of three commonly used pressable all ceramic core materials. Ninety glass ceramic specimens were fabricated from three commercially available leucite based core ceramic material (1) Esthetic Empress, (2) Cergo, and (3) Performance Plus. Thirty discs of each material were divided into three groups of 10 discs each. Biaxial flexural strength (30 discs,) Biaxial flexural strength for samples treated with 9 % HF acid (30 discs) and fracture toughness (30 discs) were evaluated. Core material Performance Plus had the lowest biaxial strength of 124.89 MPa, Cergo had strength of 152.22 MPa and the highest value of 163.95 was reported for Esthetic Empress. For samples treated 9 % HF, Performance Plus had the lowest biaxial strength of 98.37 MPa, Cergo had strength of 117.42 MPa and the highest value of 143.74 was reported for Esthetic Empress. Core material Performance Plus had the lowest fracture toughness of 1.063 MPa, Cergo had strength of 1.112 MPa and the highest value of 1.225 was reported for Esthetic Empress. The results shows that Esthetic Empress had better mechanical properties compared to Cergo had Performance Plus in relation to the parameters tested.

Evaluation of Bone Density Around the Implants Placed Using Drilling Technique and Bone Expansion Technique: An In vivo Study.

Bone density is a key parameter in determining the surgical procedure of implant placement and for the predictability of successful implant treatment. Several clinical studies have shown lower survival rates of implants in maxilla which was attributed to poor bone quality. The present study compared the variations in the pre-operative and post-operative bone density values in Hounsfield units using CT between drilling technique and bone expansion technique at 0.25 and 1.0 mm sections at two sites which were selected in maxillary arch between the second premolar regions of either quadrants and results have shown bone expansion technique is superior to drilling technique in division III bone.

Rehabilitation of maxillary arch with attachment-retained mesh-reinforced single complete denture.

Fabrication of conventional complete dentures was one of the most commonly advised treatment options to mange edentulous patients since many years. One of the commonly encountered challenging tasks in prosthodontics is a clinical situation in which patients have maxillary completely edentulous arches opposing mandibular natural dentition. This situation can be effectively managed by retaining some of the natural teeth as overdenture abutments. Tooth supported overdenture retained by attachments will improve retention, support and stability, and reduces rate of ridge resorption along with psychological benefits to the patients by providing tactile sensation. The present case report describes management of patients with edentulous maxillary arch opposing natural mandibular dentition-rehabilitated attachment-retained mesh-reinforced overdenture.