Effect of conventional and microwave glazing on surface roughness of metal ceramics: An atomic force microscopy analysis.

PURPOSE: This study investigated and compared the surface roughness achieved by glazing porcelain samples in a conventional and a microwave oven. MATERIALS AND METHODS: Two commercial brands of metal ceramics were used, VITA VMK MASTER and IPS CLASSIC. Sixty samples were fabricated, 30 for each type of ceramic. The samples were sintered in the conventional oven and hand-polished to remove any irregularities. Samples (n = 10) from each type of ceramic were further divided into three groups as follows: hand-polished (Group A), conventional oven glazed (Group B), and microwave glazed (Group C). Each specimen was evaluated for surface roughness by atomic force microscope. Data were statistically analyzed using two-way analysis of variance (ANOVA) and Tukey's post hoc test (a = 0.05). RESULTS: Two-way ANOVA indicated a highly significant difference in surface roughness based on the type of glazing (P < 0.001), there was a significant difference based on the metal ceramics (P = 0.002). There was also a significant interaction between the type of glazing and metal ceramics (P = 0.009). The images obtained from the atomic force microscope corroborated the measured values. CONCLUSIONS: All the results indicate that microwave glazing can be a feasible option for glazing porcelain specimens. It was concluded that surface topography is influenced by surface treatment and microwave glazed ceramic is superior to conventional oven glazed ceramic and hand-polishing showed greater surface roughness when compared to glazing. IPS CLASSIC ceramic showed relatively smooth surface when compared to VITA VMK MASTER irrespective of the surface treatment.

Prosthetic Rehabilitation of Hemimandibulectomy Defect with Removable Partial Denture Prosthesis Using an Attachment-Retained Guiding Flange.

The restoration of normal function and esthetics is often challenging in the prosthetic rehabilitation of patients with hemimandibulectomy defects due to unstable occlusion and mandibular deviation. The extensive period of time for completion of healing of the reconstructed mandible through reconstructive plastic surgery and/or implant-assisted prosthesis may compromise the masticatory function by causing delay in the fabrication of definitive prosthesis. This case report describes a novel technique for the construction of customized attachment-retained mandibular guiding flange prosthesis for immediate rectification of the frontal plane rotation occurring after hemimandibulectomy.

Effect of comonomer of methacrylic acid on flexural strength and adhesion of Staphylococcus aureus to heat polymerized poly (methyl methacrylate) resin: An in vitro study.

AIMS AND OBJECTIVE: The purpose of the present study was to evaluate and compare flexural strength and Staphylococcus aureus adhesion of heat-activated poly (methyl methacrylate [MMA]) resin modified with a comonomer of methacrylic acid (MAA) and MMA monomer. MATERIALS AND METHODS: Comonomer preparation was done with the addition of varying concentration of MAA (0, 15, 20, and 25 wt %) to the MMA of conventional heat-activated denture base resin to prepare the specimens. Prepared specimens were stored in distilled water at 37°C for 1 day and 1 week before the evaluation of flexural strength and microbial adhesion. Flexural strength was measured using a universal testing machine at a crosshead speed for 2 mm/min (n = 10). Microbial adhesion (colony-forming unit [CFU]) was evaluated against S. aureus using a quadrant streaking method (n = 5). Data were subjected to one-way ANOVA, and the significant differences among the results were subjected to Tukey's HSD test. P < 0.05 was considered statistically significant. RESULTS: Addition of MAA to the MMA monomer was found to significantly reduce the adhesion of S. aureus for all the groups. Reduction of CFU of S. aureus was found be more significant for Group 3 as compared to control, both at 1-day (P < 0.001) and 1-week (P < 0.002) storage in distilled water. However, no statistically significant changes in the flexural strength were observed with the addition of MAA at 1-day (P = 0.52) and 1-week (P = 0.88) time interval. CONCLUSION: Addition of MAA to conventional denture base resin reduced the microbial adhesion without significantly affecting the flexural strength.

Prosthetic rehabilitation of a patient with near total maxillectomy using a hollow bulb obturator: a case report

Aim: To prosthetically rehabilitate maxillary defect in a patient with near total maxillectomy using hollow bulb obturator. Case description: Authors report a case of 64-year-old male patient with near total maxillectomy with respect to the left side who was referred for the prosthetic rehabilitation. Conclusions: The hollow bulb definitive obturator prosthesis rehabilitated the patient in terms of masticatory function, phonetics and esthetics. The hollow bulb design ensured patient comfort due to its decreased weight.

Functional and aesthetic rehabilitation of a geriatric patient with cleft palate: a case report.

Cleft palate defect with complete edentulism in elderly patients presents a prosthodontic challenge for complete denture fabrication. Such large defects are very difficult to restore by surgical intervention and have direct consequence on such functions as mastication and speech, on aesthetics, and on the patient's mental attitude. This article describes a case report in which a 76-year-old female patient underwent restoration with a closed hollow bulb obturator for a large cleft palate defect.

Replacement of missing anterior tooth using screw retained implant prosthesis in the esthetic zone: a case report with 3 years of follow up.

As more and more dental practitioners are focusing on implant-supported fixed restorations, some clinicians favor the use of cement retained restorations while others consider screw-retained prosthesis to be the best choice. As both types of prostheses have certain advantages and disadvantages, clinicians should be aware of the limitations of each type. Screw-retained implant restorations have an advantage of predictable retention, retrievability and lack of potentially retained sub-gingival cement. However, a few disadvantages exist such as precise placement of the implant for optimal and esthetic location of the screw access hole and obtaining passive fit. On the other hand, cement retained restorations eliminates unaesthetic screw access holes; have passive fit of castings; reduce stress to splinted implants because of minor misfit of the framework; reduced complexity of lab procedures; enhanced esthetics; reduced cost factors and non disrupted morphology of the occlusal table. This case report presents the replacement of missing left central incisor using screw-retained implant prosthesis due to palatal trajectory of the implant placement and inadequate abutment height for retention of cement retained prosthesis.

Spring-loaded custom tray: an alternative technique for recording impressions in a patient with a restricted mouth opening.

For patients with extensive head and neck injuries due to trauma and/or extensive surgical procedures, their ability to open the mouth is severely limited. Prosthodontic treatment of these patients often leads to compromised impressions and prostheses. When making an impression, a wide mouth opening is necessary to ensure both proper tray insertion and the correct alignment during border molding procedures. For patients with a restricted mouth opening, it may be necessary to modify the standard impression procedure to fabricate a prosthesis successfully. This article describes an alternative method for fabricating a custom impression tray for a complete denture in patients with limited mouth opening abilities.

Three-dimensional orientation of iris in an ocular prosthesis using a customized scale.

The success of an ocular prosthesis depends largely on the correct orientation of the iris disk. Various methods have been put forth to achieve this. This article emphasizes one such simplified method, wherein a customized scale has been used to orient the iris disk mediolaterally, superoinferiorly, and anteroposteriorly in an ocular prosthesis. A scleral wax pattern was fabricated. The customized scale was used to measure the dimension and orientation of the natural iris. These measurements were then transferred to the scleral wax pattern with the customized scale. An iris disk was fabricated using black crayon on the scleral wax pattern according to the measurements. The scleral wax pattern, including the iris disk, was then placed in the eye socket to verify its dimension and orientation. A prefabricated iris disk was modified according to the measured dimensions and transferred to the final scleral wax pattern. The transfer of these dimensions to the definitive prosthesis was achieved successfully, ultimately improving the patient's social and psychological well being.

Evolution of surgical guidance in implant dentistry.

UNLABELLED: The optimal positioning of oral implants ensures good biomechanical, functional, aesthetic and phonetic results.The concept of surgical guidance in implant dentistry has been developed to bridge the gap between pre-operative treatment planning and surgical site preparation.This article discusses its evolution, from the early surgical guide systems which used only diagnostic casts as reference, to the latest in computer-assisted navigation. CLINICAL RELEVANCE: Surgical guidance allows the accurate transfer of information from the pre-operative treatment planning phase to the surgical field. It assists the operator in placing the implant in the most ideal position and angulations, with regards to the final prosthesis.

An innovative technique to restore velopharyngeal incompetency for a patient with cleft lip and palate.

Treatment of cleft lip and palate patients often demand well-coordinated work of medical and dental specialists. In spite of surgical and orthodontic therapy, prosthetic rehabilitation is always necessary because of partial anadontia, maxillary hypoplasia and velopharyngeal dysfuction. The aim of the prosthetic treatment is to improve aesthetics, function and speech of the patients; however, factors like underdeveloped and collapsed maxillary arch, retrognathic maxilla and reduced alveolar ridge height make the treatment challenging. This clinical report describes an interdisciplinary approach for the management of cleft lip and palate patient associated with mutilated dentition. The prosthetic phase began along with orthodontic treatment to achieve sufficient space distribution, which was restored with fixed dental prosthesis to stabilise the achieved status of occlusion. Palatal lift prosthesis was fabricated to restore the velopharyngeal incompetency with an innovative technique using 'standard orthodontic expansion screw' to eliminate hypernasality, decrease intelligibility of speech and to aid in deglutition.

Fabrication of a surgical splint in an emergency situation: a clinical report.

Fractures involving pediatric jaws most often require a splint to prevent the fragments from being displaced; however, impression making presents a challenge. This article describes the fabrication of a surgical splint over an ideal cast, which is subsequently refitted with a tissue conditioner onto the patient's jaw. The highlight of this technique is the elimination of an impression procedure, thereby reducing clinical and laboratory time and easing pain in the child.

Implant crest module: a review of biomechanical considerations.

The success of dental implants has long been established through various studies with a particular emphasis laid on an implant design. Crest module is that portion of a two-piece metal dental implant, designed to hold the prosthetic components in place and to create a transition zone to the load bearing implant body. Its design, position in relation to the alveolar crest, and an abutment implant interface makes us believe that, it has a major role in integration to both hard and soft tissues. Unfortunately, in most clinical conditions, early tissue breakdown leading to soft tissue and hard tissue loss begins at this region. Early crestal bone loss is usually highest during the first year after placement ranging from 0.9 to 1.6mm and averaged 0.05-0.13 mm in the subsequent years . Various hypotheses have been stated to reason it however, none has been proved convincingly. In light of this, various attempts have been made to overcome this undesirable bone loss, by varying an implant design, the position, surgical protocol, and the prosthetic options. Irrespective of an implant system and designs that are used, crestal bone loss of up to the first thread is often observed. The purpose of this review is to look into the various designs and treatment modalities, which have been introduced into the crest module of an implant body to achieve the best biomechanical and esthetic result.

Validation of implant stability: a measure of implant permanence.

Implant stability is a requisite characteristic of osseointegration. Without it, long-term success cannot be achieved. Continuous monitoring in a quantitative and objective manner is important to determine the status of implant stability. Measurement of implant stability is a valuable tool for making decisions pertaining to treatment protocol and also improves dentist-patient communication. Owing to the invasive nature of histological analysis, various others methods have been proposed like radiographs, cutting torque resistance, reverse torque, modal analysis, resonance frequency analysis and Implatest® . This review focuses on objectives and various methods to evaluate implant stability.

Overdenture with accesspost system: a clinical report.

A patient presented with an unfavorable distribution of teeth in the arch which precluded treatment with a removable partial denture. The unique pattern of partial edentulism was treated with an overdenture restoration using accesspost system. The final restoration was stable, well retained and esthetic, serving as a conservative approach to root preservation.

Prosthetic rehabilitation of a complete bilateral maxillectomy patient using a simple magnetically connected hollow obturator: a case report.

AIM: The purpose of this clinical report is to present a description of the prosthetic rehabilitation of a bilateral complete maxillectomy patient using a two piece magnetically connected prosthesis. BACKGROUND: A complete bilateral maxillectomy defect presents a considerable reconstructive challenge for the prosthodontist. It results in devastating effects on cosmetic, functional, and psychological aspects of the patient. REPORT: A 46-year-old woman reported with a chief complaint of missing teeth in the upper jaw. Her primary concerns were a poor facial appearance, inability to chew food, and regurgitation of the food into the nasal cavity. She was diagnosed with carcinoma of the maxillary sinus, for which a bilateral maxillectomy was done followed by post surgical radiation therapy. The prosthetic treatment objectives were to separate the nasal and oral cavities, restore the mid-facial contour, and improve her masticatory functions by providing a full complement of maxillary teeth using a two-piece connected hollow obturator prosthesis connected by a magnet. SUMMARY: Insertion and removal of a large prostheses used for rehabilitation of midfacial defects requires good neuromotor coordination and an adequate mouth opening. Because these factors were problematic for this patient, the treatment plan was to fabricate a two piece magnetically connected prosthesis. After fabrication and insertion of the prosthesis, the fit between two sections was evaluated and instructions for insertion, removal, and maintenance of the obturator were given. The patient's speech, masticatory efficiency, and swallowing dramatically improved after insertion.