A comparative study on the effect of polishing systems on the color and surface texture of different porcelain systems - feldspathic, pressable, and computer-aided design/computer-aided manufacturing.

Aim: To find and compare the qualitative and quantitative change in color and surface texture of feldspathic ceramic, pressable ceramic and ceramic used in computer-aided design/computer-aided manufacturing CAD/CAM after different surface treatments namely glazing, abrading and polishing. To compare the effectiveness of pearl finish polishing paste and Soflex polishing system used in the study. Setting and Design: In-vitro, comparative study. Materials and Methods: Disc-shaped feldsapathic, pressable, CAD/CAM ceramic specimens were fabricated. Surface roughness and color parameters Δ L*, Δa*, and Δ b* were measured before glazing, after glazing, after abrasion with 02 diamond bur and after polishing with two different polishing systems. Surface roughness was measured qualitatively using scanning electron microscopy and quantitatively using an optical profilometer. The value of color parameters was obtained using a colorimeter. Data were statistically analyzed with ANOVA. Statistical Analysis Used: SPSS software 20.0 version (IBM, New York, United states of America). Results: Unglazed feldspathic, pressable and CAD/CAM porcelain specimens showed a mean surface roughness value of 2.73 ± 0.38, 3.54 ± 1.42, and 3 ± 1.74 specimens. After glazing and polishing, the surface roughness values decreased. After abrasion, surface roughness values increased. Polishing did not alter the color along the red green axis and yellow blue axis. Conclusions: Abraded specimens of feldspathic, pressable and CAD/CAM after polishing using pearl finish polishing paste and Soflex disc became smoother than glazed specimens. When pearl finish polishing paste and Soflex discs were compared for their effectiveness the former appeared to be more superior but not to a significant level. Mechanically altering feldspathic, pressable, and porcelain used in CAD/CAM technology does not cause any change in shade.

Fabrication of a magnetic holder for the removal of ocular prosthesis.

Long-term success of ocular prostheses is dictated by the retentive quality which is usually ensured by maximum possible extension into the sulcus of the eyelids. Majority of the patients experience difficulty during manual placement and removal of the prosthesis, especially when the sulcus is very deep. Ocular prosthesis is commonly removed with fingers or suction cups. Although the suction cups are popular, its efficiency lasts only for a limited period. Moreover, it is not easily available in the rural Indian market. This article presents the design of a magnetic instrument for the placement and removal of the ocular prosthesis.

Effect of joining the sectioned implant-supported prosthesis on the peri-implant strain generated in simulated mandibular model.

AIM: The aim of this study is to evaluate the strain developed in simulated mandibular model before and after the joining of an implant-supported screw-retained prosthesis by different joining techniques, namely, arc welding, laser welding, and soldering. MATERIALS AND METHODS: A specimen simulating a mandibular edentulous ridge was fabricated in heat-cured acrylic resin. 4-mm holes were drilled in the following tooth positions; 36, 33, 43, 46. Implant analogs were placed in the holes. University of California, Los Angeles, abutment was attached to the implant fixture. Eight strain gauges were attached to the acrylic resin model. Six similar models were made. Implant-supported screw-retained fixed prosthesis was fabricated in nickel-chromium alloy. A load of 400 N was applied on the prosthesis using universal testing machine. Resultant strain was measured in each strain gauge. All the prostheses were sectioned at the area between 36 and 33, 33 and 43, and 43 and 46 using 35 micrometer carborundum disc, and strain was measured in each strain gauge after applying a load of 400 N on the prosthesis. Specimens were joined by arc welding, soldering, and laser welding. After joining, a load of 400 N was applied on each prosthesis and the resultant strain was measured in each strain gauge. RESULTS: Highest mean strain values were recorded before sectioning of the prostheses (889.9 microstrains). Lowest mean strain values were recorded after sectioning the prosthesis and before reuniting it (225.0 microstrains). CONCLUSIONS: Sectioning and reuniting the long-span implant prosthesis was found to be a significant factor in influencing the peri-implant strain.

Ultrasonic evaluation of influence of hard acrylic resin denture on blood flow of mandibular denture supporting mucosa utilizing duplex color Doppler studies: An in vivo study.

AIMS: To determine the influence of hard acrylic denture base materials on the blood flow of mandibular denture supporting mucosa over a period of six months time. MATERIALS AND METHODS: Select fifteen edentulous patients of age 55-75 years. The blood flow of the mandibular denture supporting mucosa was measured bilaterally in the molar region and in the incisor region utilizing Ultrasound colour Doppler (2D and Duplex Imaging). Measurements were performed prior to denture insertion and later after the dentures were worn for 1 month, 2 months, 3 months, 4 months, 5 months and 6 months. STATISTICAL ANALYSIS USED: Mean blood flow as measured by Ultrasound colour Doppler were tabulated significant changes if any at various time interval in comparison to baseline was assessed by Kruskalwallis ANOVA test followed by Wilkoxan sign rank test for pairwise comparison. (In the present study, P < 0.05 was considered as the level of significance). RESULTS: The denture supporting mucosa exhibited a progressive reduction in the blood flow both with hard denture. The blood flow change with hard denture was a reversible condition as the blood flow improved at the end of six months. Kruskalwallis ANOVA test revealed no significant change in the blood flow at any interval of time in comparison to base value (P = 0.133). CONCLUSIONS: Within the limitations of the study denture supporting mucosa exhibited a progressive reduction in the blood flow with hard denture which was reversible.

Prosthetic Rehabilitation of Lower Limb with RTV Siliconee Using Prosthodontic Clinical and Laboratory Techniques - A Case Report.

Amputation of all or part of a limb may be due to systemic disease, vascular disease, infection, local injury or trauma. Partially amputated lower limbs present a variety of unique clinical and prosthetic challenges, because of distinctly different amputation levels of the lower limb. A female patient with history of Partial Foot Amputation (PFA) surgery at metatarsophalangeal joint level, due to crush injury reported for prosthetic rehabilitation. This case was successfully rehabilitated using room temperature vulcanizing (RTV) medical grade silicone for fabrication of foot prosthesis. Though limited in its function, it amply proves that the clinical and laboratory techniques used in fabrication of maxillofacial prosthesis can be effectively adapted for the fabrication of body prosthesis like toes and feet to enhance the quality of life of the patients. The patient was reviewed every year for three years.

An innovative simplified method for assessing available bone in mandible for implant.

The primary factor that determines the success of implant is the amount of available bone in the edentulous site. Diagnostic imaging and techniques help to develop and implement a cohesive and comprehensive treatment plan according to the available bone. In the following case report an innovative simplified method (poor man CT) is used to fabricate a three dimensional model to assess the available bone for implant placement in mandible.

Using an existing crown to repair a damaged cast post and core restoration.

A fractured coronal tooth structure beneath an intact crown is a common clinical occurrence. If the underlying root is healthy, the tooth is restored with a post and core followed by refabrication of the crown. This paper describes a technique of using the existing intact crown for the above-mentioned situation. A 34-year-old female was referred with a fractured right canine with an intact crown. A post was found fractured in the canal which was subsequently retrieved. A new fiber post was cemented in the post space followed by adaptation of 50 µm polytetrafluoroethylene (teflon) tape on the tissue surface of the crown. Dual-cured core build-up composite resin was injected into the crown and adapted to the fractured tooth. On curing and removal of the crown, a new composite resin core was found bonded to the tooth structure. The Teflon tape was removed from the crown, and the crown cemented to the core using glass ionomer cement. This technique of building up the core of the tooth using teflon tape adapted to the tissue surface of the crown was found to be successful even after 1 year of follow-up.

Prosthodontic Treatment Preferences in Post Independent India: An over View.

Indian prosthodontics do not have a chronological document. This article is an attempt to record the event based prosthodontic history of India. This is a starting point.

Titanium dioxide as an osteoconductive material: an animal study.

The purpose of the present study was to evaluate the biocompatibility and osteoconductive potential of pure and pigment forms of titanium dioxide. Pure and pigment forms of titanium dioxide were incorporated into prepared bur holes in the femur bone of rabbits. Implantation was done on six Albino rabbits which were sacrificed at the end of 3rd, 4th and 5th months after implantation. Radiographic, histologic and scanning electron microscopic evaluations of the implanted sites were performed. Heamatologic and soft tissue response to these materials were also evaluated. The results showed that both pure and pigment forms of titanium dioxide are biocompatible and have good osteoconductive properties. It was concluded that titanium dioxide can be effectively used in the augmentation of osseous defects and inadequate ridge forms.

Simplified technique for orbital prosthesis fabrication: a clinical report.

Loss of orbital content can cause functional impairment, disfigurement of the face, and psychological distress. Rehabilitation of an orbital defect is a complex task, and if reconstruction by plastic surgery is not possible or not desired by the patient, the defect can be rehabilitated by an orbital prosthesis. The prosthetic rehabilitation in such cases depends on the precisely retained, user-friendly removable maxillofacial prosthesis. Many times, making an impression of the orbital area with an accurate record of surface details can be a difficult procedure. The critical areas are making a facial moulage, mold preparation, and attaching the retention device, particularly when eyeglass frames are used. This case focuses on these hindrance factors. A simple basket was used for the impression tray to obtain the facial moulage. A putty mold was used, and attachment of the prosthesis to a retention device was accomplished with positional distance. This method proves to be an economical and simple way of making an orbital prosthesis.

Teaching, research, and job satisfaction of prosthodontic faculty members in Indian academic dental institutions.

The aim of this study was to determine prosthodontic faculty members' satisfaction with their roles of teaching, research, and service in academic dental institutions of India. The head of the prosthodontic department of each institution was informed of the study by telephone and asked to invite his or her staff members to complete a questionnaire. The questionnaire used a rating scale of 1=very dissatisfied, 2=dissatisfied, 3=neutral, 4=satisfied, and 5=very satisfied. The satisfaction score for each of the three categories was determined by summing the weights for all items related to the variable. In the study, 386 prosthodontic faculty members from 184 dental institutions were invited to participate, and 341 faculty members from 139 dental institutions completed the questionnaire. The data obtained were analyzed using statistical software. Most of the respondents were satisfied with their teaching and service items. Neutral responses were made for institutional teaching rewards, institutional financial support for research, release time offered by the institution, support for sabbatical leaves, technical assistance in analyzing data, secretarial and technical assistance, institutional research rewards, in-service training opportunities, and institutional service rewards. Dissatisfied responses were made regarding financial and academic support for making scientific presentations and attending conferences and seminars.

Validation of resonance frequency analysis by comparing implant stability quotient values with histomorphometric data.

The study was designed to determine the relationship between implant stability quotient (ISQ) values measured using resonance frequency analysis (RFA) and implant-bone distance measured histomorphometrically. Ten identical implants were equally divided into 2 groups based on primary stability at placement. Osteotomies were prepared in harvested goat femurs. ISQ values were measured and compared with implant-bone distance determined by micrometry. Based on the results, it was concluded that RFA can be used to measure implant stability reliably.

Alginate impressions: A practical perspective.

The choice of an impression material for a particular situation depends on the treatment being provided, operator preference, and so on. Even with the introduction of more advanced and more accurate rubber base impression materials, irreversible hydrocolloid impression materials have stood the test of time. This article gives a detailed perspective of how best to make alginate impressions.