Clinical study to evaluate the wear of natural enamel antagonist to zirconia and metal ceramic crowns.

STATEMENT OF PROBLEM: Tooth wear is a complex process, which, if not prevented, may adversely affect the integrity of the stomatognathic system. Different restorative dental materials may affect the amount of wear on natural enamel antagonists. PURPOSE: The purpose of this in vivo study was to evaluate and compare the wear of enamel opposing natural enamel, zirconia, and metal ceramic crowns after 1 year. MATERIAL AND METHODS: Ten participants between 18 and 35 years of age requiring 2 complete crowns, 1 on either side of maxillary or mandibular molar region, and having healthy natural teeth in the opposing arch were selected. For each participant, 1 monolithic polished zirconia crown and 1 glazed metal ceramic crown were fabricated and cemented. To evaluate the wear of the antagonistic natural enamel (premolar and molar), polyvinyl siloxane impressions were made immediately (baseline) and at 1 year after cementation. The wear of natural enamel against natural enamel was evaluated as the control. The resulting casts were scanned (using a 3D white light scanner), and 3D software was used to calculate the maximum amount of linear wear. RESULTS: One-way repeated measures ANOVA was conducted to analyze data. Mean ±SD occlusal wear of the antagonistic enamel 1 year after the cementation of metal ceramic crowns was 69.20 ±4.10 µm for premolar teeth and 179.70 ±8.09 µm for molar teeth, whereas for zirconia crowns, it was 42.10 ±4.30 µm for premolar teeth and 127.00 ±5.03 µm for molar teeth. Occlusal wear of natural enamel opposing natural enamel was 17.30 ±1.88 µm in the premolar region and 35.10 ±2.60 µm in the molar region. The Bonferroni post hoc test revealed that the occlusal wear of antagonistic enamel 1 year after the cementation of a metal ceramic crown was significantly higher (P<.001) than that of an opposing zirconia crown or natural enamel. CONCLUSIONS: Zirconia crowns led to less wear of antagonist enamel than metal ceramic crowns, but more than natural enamel.

Prosthodontic rehabilitation of patient with marginal mandibular resection using attachment supported prostheses: A clinical report.

Marginal mandibular resection to treat neoplasms leads to loss of alveolar bone and teeth at the affected side. Consequently patient suffers with poor masticatory performance and esthetic disfigurement, which we need to restore with the help of prosthodontic rehabilitation. The success of rehabilitation of these patients depends on strategic treatment planning and choice of most suitable treatment modality. In this article, case of a patient has been presented who underwent marginal mandibular resection and reported with many limiting factors like obliterated buccal and lingual sulci, attachment of lingual frenum and lower lip at the level of alveolar ridge and Macroglossia. Impression making and fabrication of a retentive prosthesis were the main challenges. Therefore, a modified impression technique was used to fabricate mandibular cast partial denture with extracoronal semi precision attachments to enhance the retention of the prosthesis.

Clinical considerations for prosthodontic rehabilitation of intermediate form of osteopetrosis: A report of two cases.

INTRODUCTION: Osteopetrosis is a rare autosomal hereditary disorder characterized by abnormal functioning of osteoclasts, which leads to delayed wound healing. Hence chances of infection are increased even after minor surgical procedures. This paper aims to describe clinical features, and prosthodontic management of two patients who presented with clinical features of intermediate form of osteopetrosis and missing teeth. CASE REPORT: A 27-year-old patient having intermediate osteopetrosis presented with difficulty in chewing food and swallowing, due to edentulous maxillary and mandibular arches with large antral cavities, which developed secondary to tooth extraction. Another case discussed is a 25-year-old female patient who reported with chief complaints of difficulty in chewing due to resected left side of lower jaw. In these case reports, importance of avoiding extractions, preservation of remaining teeth and conservative management with minimum number of patients' visits has been emphasized. CONCLUSION: Efforts should be made to avoid dental extraction in such cases as chances of bone infection and fracture are more. If patient is partially or completely edentulous only removable type of prosthesis is advisable as bones are hypocalcified and maintenance of oral hygiene is easy with removable prosthesis.