Gunjan Pruthi

Effect of bleaching on color change and surface topography of composite restorations.

This study was conducted to determine the effect of 15% carbamide peroxide bleaching agent on color change and surface topography of different composite veneering materials (Filtek Z350 (3M ESPE), Esthet X (Dentsply India), and Admira (Voco, Germany). Methods. 30 samples were fabricated for evaluation of color change using CIELAB color system and Gonioreflectometer (GK 311/M, ZEISS). 45 disc-shaped specimens were made for evaluation of surface topography after bleaching (Nupro White Gold; Dentsply) using SEM. Statistical analysis. One way ANOVA and Multiple comparison tests were used to analyze the data. Statistical significance was declared if the P value was .05 or less. Results and conclusion. All the specimens showed significant discoloration (ΔE > 3.3) after their immersion in solutions representing food and beverages. The total color change after bleaching as compared to baseline color was significant in Filtek Z350 (P = .000) and Esthet X (P = .002), while it was insignificant for Admira (P = .18). Esthet X showed maximum surface roughness followed by Admira and Filtek Z350. Bleaching was effective in reducing the discoloration to a clinically acceptable value in all the three groups (ΔE < 3.3).

A Novel Method for Retention of an Orbital Prosthesis in a Case with Continuous Maxillary and Orbital Defect

Exenteration of the orbital contents as well as removal of a part of maxilla with an ablative surgery for the removal of a malignant tumor can severely affect a person in terms of function, esthetics and psychological trauma. A well-retained, user-friendly, removable maxillofacial prosthesis is the key to successful prosthetic rehabilitation in such cases. Various retentive techniques include using spectacle frame, conformers, adhesives, osseointegrated implants, magnets or buttons. This paper describes a novel technique for retention of silicone orbital prosthesis using acrylic resin base attached to maxillary obturator with the help of pin and socket of an electric plug wherein the latter is attached to the eye prosthesis with the help of a mechanical undercut. This helps in better retention of both the prostheses.

Prosthetic rehabilitation after orbital exenteration: a case series.

Orbital exenteration is executed by the ophthalmic surgeon to treat various neoplasms or non-malignant diseases. But it leads to several functional, esthetic and psychological problems for the patients. Orbital prosthesis is a good alternative for cosmetic and psychological rehabilitation, if reconstructive surgery is not possible or not desired by the patient. In the following article, different materials and retentive aids for fabrication of an orbital prosthesis given in the literature along with few novel methods have been discussed for four patients who underwent orbital exenteration. Factors that an ophthalmic surgeon should consider during surgery, which may later on help the prosthodontist to obtain good cosmetic results, are also discussed briefly. Remarkable results can be obtained if both work as a team for one common goal i.e. improvement of quality of life of the patient after orbital exenteration.

A comparative study to measure the condylar guidance by the radiographic and clinical methods

PURPOSE The study was conducted to compare the radiographic and clinical methods of measuring the horizontal condylar guidance (HCG) values. MATERIALS AND METHODS The condylar guidance was measured using the radiographic (CT scan) and three clinical methods i.e. the wax protrusive records, Lucia jig record and intraoral central bearing device in 12 patients aged between 20-40 years irrespective of sex. The records were taken and transferred on the semi-adjustable articulator to record the HCG values. The CT scan was taken for 3D reconstruction of the mid facial region. Frankfort horizontal plane (FHP) and a line extending from the superior anterior most point on the glenoid fossa to the most convex point on the apex of articular eminence (AE) was marked on the CT scan. An angle between these two lines was measured on both right and left sides to obtain condylar inclination angle. Three interocclusal protrusive wax and jig records were taken and transferred to the semi adjustable articulator. Three readings were recorded on each side. Similarly the records were taken and transferred to the same articulator using the intra oral central bearing device to record the readings. RESULTS The statistical analysis showed insignificant differences in the HCG values between the right and left sides [(P=.589 (CT), P=.928 (wax), P=.625 (jig), P=.886 (tracer)]. The clinical methods provided low Pearsons correlation values [(R = 0.423 (wax), R = 0.354 (jig), R = 0.265 (tracer)] for the right as well as the left sides when compared with the CT values. Among the clinical methods, jig and wax method showed strong level of association which is statistically significant while the intra-oral tracer showed weak association with the other two methods. CONCLUSION The right and left HCG values were almost similar. The CT scan showed higher HCG values than the clinical methods and among the clinical methods, values obtained from all the methods were comparable.

Comparison of Marginal Fidelity and Surface Roughness of Porcelain Veneers Fabricated by Refractory Die and Pressing Techniques

PURPOSE The aim of the present study was to compare the marginal fidelity and surface roughness of porcelain veneers fabricated by the refractory die and pressing techniques under in vivo conditions. MATERIALS AND METHODS A total of 72 veneers were prepared for anterior teeth in 12 participants. Veneers on anterior teeth in the first and second quadrants were fabricated using refractory die (group I) and pressing techniques (group II), respectively. Surface roughness was evaluated using a profilometer in three areas (cervical, mesio-incisal, disto-incisal) for each veneer. Marginal adaptation of all the veneers (N = 36/group) was evaluated at each margin (cervical, incisal, mesial, and distal) at 7 days and at 3 months after cementation under a scanning electron microscope (SEM) at 200× magnification. RESULTS The mean surface roughness of veneers in cervical, mesio-incisal, and disto-incisal areas was 0.41 ± 0.25, 0.33 ± 0.14, and 0.32 ± 0.14 μm, respectively, for group I; and 0.31 ± 0.11, 0.36 ± 0.18, and 0.29 ± 0.11 μm, respectively, for group II. Intra- and intergroup comparisons showed no statistically significant values for all areas (p > 0.05). In 144 margins evaluated for each group, a visible gap was present in 15 (10.4%) and 18 (12.5%) recordings at 7 days for groups I and II, respectively. They increased to 19 (13.1%) and 20 (13.8%) after 3 months. These gaps were further broken down into percent distribution of total recordings at the cervical, incisal, mesial, and distal margins. Intragroup comparison was made using the Cochrane test. The chi-square test and Fishers exact test were used for intergroup comparison of margins, revealing no statistical difference (p > 0.05) CONCLUSION: Within the limitations of the study, the surface roughness and marginal fidelity of porcelain veneers fabricated by refractory die technique and pressing technique were comparable.

Light weight prosthesis for a patient with bilateral orbital exenteration—A clinical report

PATIENT This article describes a case report of a patient with history of bilateral orbital exenteration due to squamous cell carcinoma. Spectacle retained acrylic prosthesis was considered to be the best possible option in this case due to total lack of vision and related manual dexterity. DISCUSSION Main challenge in fabrication of spectacle retained prosthesis is to maintain its adaptation with the tissues during attachment of the screws. So, method of attachment of prostheses with the frame has been discussed in detail. The other concern was the increased weight of the prosthesis and associated discomfort to the patient, as both artificial eyes had to be attached to one frame. Therefore, procedure to reduce the weight of the prosthesis is also discussed. CONCLUSION Successful prosthodontic rehabilitation is based on the selection of most suitable maxillofacial prosthetic material and appropriate retentive aid for each patient. Though spectacle retained acrylic prosthesis is a conventional method, it was a user friendly and economical option for this patient.

Prosthodontic rehabilitation of combined oronasal defect in patients with non-Hodgkin's lymphoma using two different attachments: Two case reports

Debridement of affected parts in patients with non-Hodgkins lymphoma leads to large mid facial defects leading to poor quality of life due to cosmetic disfigurement and various functional comorbidities. Therefore, a surgeon should refer the patients to a prosthodontist for replacement of lost tissues to improve their function and esthetics. Two cases have been presented here with a history of non-Hodgkins lymphoma having large, continuous defects involving nose, cheeks, and maxilla. Retaining large facial prosthesis and intraoral obturator was a challenge as supporting hard and soft tissues were less. Two-piece lightweight prostheses were fabricated and retained with the use of very economical titch buttons used (used in clothes) in case 1 due to financial constraints and slightly expensive iron boron neodymium magnets in case 2. Functional and esthetic rehabilitation was successfully achieved with intraoral and facial prostheses attached to each other.

Effect of denture soft liner on mandibular ridge resorption in complete denture wearers after 6 and 12 months of denture insertion: A prospective randomized clinical study

Purpose: Soft liners act as a cushion between the denture base and the residual ridge. Hence, it is important to study their effect on resorption of mandibular denture bearing area. Therefore, the purpose of this study was to evaluate the influence of soft denture liner on mandibular ridge resorption after 1 year in completely denture wearers. Materials and Methods: Twenty-eight completely edentulous patients having age between 45 and 60 years with well-formed ridges in class I jaw relations were selected as per the inclusion and exclusion criterion. Randomization chart was used to enroll participants in experimental and control groups who were given mandibular dentures with and without soft denture liner, respectively. Vertical measurements were made on orthopantomograph and analyzed using Adobe Photoshop 7.0 software at five points, i.e., one at central incisor and two points at right and left first premolars and two in each first molar region. Results: On application of repeated measures analysis of variance, both groups showed a significant change in bone height after denture delivery (P < 0.05). Intergroup comparison (Wilcoxon rank sum test) of bone height in different regions at various time intervals showed statistically significant difference in bone levels (P < 0.05) from baseline to 6 months and baseline to 12months (P < 0.01), while the difference was statistically not significant during 6 and 12 months’ period. Conclusion: The use of soft denture liner significantly reduces the residual ridge resorption in complete denture wearers as compared to conventional denture wearers (without denture liner) over a period of 1 year.

Comparative evaluation of effects of bleaching on color stability and marginal adaptation of discolored direct and indirect composite laminate veneers under in vivo conditions.

Statement of Problem: Change in color and loss of marginal adaptation of tooth colored restorative materials is not acceptable. Bleaching is commonly used for treating discolored teeth. However, the literature is scanty regarding its effect on color and marginal adaptation of direct and indirect composite laminate veneers (CLVs) under in vivo conditions. Purpose: Purpose of the study was to determine the effect of bleaching on color change and marginal adaptation of direct and indirect CLVs over a period of time when exposed to the oral environment. Materials and Methods: For this purpose, a total of 14 subjects irrespective of age and sex indicated for CLV restorations on maxillary anterior teeth were selected following the inclusion and exclusion criteria. For each subject, indirect CLVs were fabricated and looted in the first quadrant (Group 1) and direct CLV′s (Group 2), were given in the second quadrant. Color change was assessed clinically using intra-oral digital spectrophotometer and marginal adaptation was assessed on epoxy resin replica of the tooth-restoration interface under scanning electron microscope. After 6 months, the subjects underwent a home bleaching regimen for 14 days using 10% carbamide peroxide. The assessment of color change and marginal adaptation was done at 6 months after veneering (0-180 days), immediately after the bleaching regimen (0-194 days) and 3 months after the bleaching regimen (0-284 days). Results: The difference in median color change (ΔE) between the groups was tested using Wilcoxon rank sum test while the median color change with time within the groups was tested using Wilcoxon signed rank test. The difference in the rates of marginal adaptation was tested between the groups using Chi-square/Fisher′s exact test. Bleaching led to statistically significant color change at cervical (CE), middle and incisal (IE) regions when direct and indirect composites were compared (P < 0.05). During intra-group comparison, direct CLV′s showed significant color change at CE and IE regions when ΔE was compared at 180 days and 284 days (CE 10 vs. CE 30, P = 0.008, IE 10 vs. IE 30, P = 0.003). No significant differences were found when within group comparison was made for indirect laminates. Intergroup comparison between the groups showed significant difference in marginal adaptation at CE margin at all-time points (at baseline, P = 0.005; at 180 days, P = 0.007; 194 days, P = 0.025; at 284 days, P = 0.067). Conclusion: After bleaching, indirect CLVs performed better in terms of color stability whereas direct CLVs performed better in terms of marginal adaptation. Clinical Significance: Indirect composites should be preferred to direct composites as veneering materials as they have better color stability. Special attention should be given to their marginal adaptation especially in the CE region. Bleaching should be avoided in patients with composite restorations in the mouth.

Author's Response: Prosthetic Rehabilitation after Orbital Exenteration: A case series

Dear Editor, We are thankful to the authors of letter to the editor entitled “improving the outcome of prosthetic rehabilitation following orbital exenteration” for having read our article and expressed their opinion.[1,2] Authors have recommended the use of heat temperature vulcanized (HTV) silicones due to its superior mechanical, esthetic and handling properties. Reference quoted by authors (Belgam et al.) nowhere states HTV silicones to be esthetic. On the contrary, literature mentions HTV silicones to have low edge strength, opaque with lifeless appearance and not adequately elastic in function.[3] Therefore, for facial prosthesis, where esthetics is a major concern, room temperature vulcanization (RTV) silicones are preferred. HTV silicones are preferred for limb prosthesis etc., because of better mechanical properties. Mahajan and Gupta have also mentioned that HTV silicones are designed for engineering applications because of higher tear resistance and they require more intense mechanical milling of solid HTV stock elastomers when compared with soft RTV silicones.[4] Fabrication of prosthesis in HTV silicones is difficult as the material requires special milling machines which are expensive and not commonly available.[5] Moreover, the references quoted for the above statement should be Bell et al.,[6] Lewis and Castleberry[7] and Lontz[8] instead of Begum et al. Second point raised by the authors is the allergic reactions because of adhesives or industrial grade silicones. Allergic reaction due to adhesives is an issue and has been already mentioned by us in our article. We have used best quality medical grade silicones (Factor II Inc., USA) for fabrication of our prostheses, not industrial grade silicones. Adhesives prescribed were also of the best quality (Dow Corning/Technovent medical adhesive) and none of our patients have reported with any allergic reaction so far. Corrosion of magnets has already been mentioned as a disadvantage in the manuscript. Attachments used in our patients may be harmful if they come into direct contact with the skin. However, the contact was only between two prostheses in our patients. Moreover, the pin and socket used were made of brass which is less prone to rust. “Photodynamic iris” uses a liquid crystal display in the prosthesis to vary the pupil size as a function of the ambient light. But, there are no clinical trials so far using this concept.[9] Use of tinted glasses, negative sphere lenses can be used but these methods mandate the use of spectacles for the patients even if the natural eye has normal power and also add to the cost. We had used these particular methods specifically because these patients had financial constraints. Prosthesis with built-in blinking mechanism are not currently available in our country. We are sorry to bring it to the notice of the editor that again the references mentioned are wrong. Osseointegrated implants undoubtedly provide better retention as compared to other mechanical methods. But, there are certain limitations already been discussed in our article. We accept evisceration and enucleation, usually followed by placement of ocular implants, are treatment of choice in painful or disfiguring blind eye instead of exenteration.