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.

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.

Modern trends in modeling of extra-oral defects.

Maxillofacial prostheses are usually fabricated on the basis of conventional impressions and techniques. The extent to which the prosthesis reproduces normal facial morphology depends on the clinical judgment and skill of the individual fabricating the prosthesis. Recently, as a result of advances in technology, various computer-aided design and manufacturing techniques have been successfully introduced for the automated fabrication of maxillofacial prostheses. These systems are able to provide more consistently accurate reproduction of facial morphology.

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.