Long-term observation of porous sapphire dental implants.
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We used porous sapphire dental implants made of alumina clinically for 4 years 1 month, commencing September, 1984 until September, 1988. Subjects consisted of 18 men and 42 women 20-71 years old (mean age: 35 years). Sixty-five implants were inserted in 60 patients. Of these, 20 were clinical cases of an implant connected with natural teeth and 45 were free-standing cases. We conducted a follow-up study on these patients over a 23-year period. One implant in 1 patient had to be removed because of postoperative infection and 8 implants in 7 patients had to be removed because of fracturing or detachment of the porous-part. This paper reports 3 cases where implants remained in place for 21-23 years. These cases have all shown good long-term clinical progress. (+info)
Orthodontic and nonorthodontic root resorption: their impact on clinical dental practice.
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Occasionally, general dentists are challenged with providing restorative treatment for a postorthodontic patient who has had moderate to severe root resorption. When this happens, a number of questions about the cause of such resorption and the appropriate treatment arise in the dentist's mind. This article will describe the orthodontic and restorative management of three patients with severe maxillary incisor root resorption, provide a thorough discussion of the currently available literature on the topic of root resorption, and answer clinical questions regarding this relatively infrequent but devastating sequel to orthodontic treatment. (+info)
The clinical success of all-ceramic restorations.
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BACKGROUND: The authors conducted a comprehensive literature review to compile and compare clinical evidence for the treatment of teeth using all-ceramic restorations. TYPES OF STUDIES REVIEWED: The authors searched the English-language peer-reviewed literature using MEDLINE and PubMed with a focus on research published between 1993 and 2008. They also conducted a hand search of relevant dental journals. They reviewed randomized controlled trials, nonrandomized controlled studies, longitudinal experimental clinical studies, longitudinal prospective studies and longitudinal retrospective studies. RESULTS: Evidence suggests that for veneers, intracoronal restorations and complete-coverage restorations for single-rooted anterior teeth, clinicians may choose from any all-ceramic system on the basis of esthetic needs (many systems have had greater than 90 percent success at six years). Well-studied molar restorations include those made of alumina and, increasingly, zirconia and bonded lithium disilicate. Reasonable evidence has shown the effectiveness of anterior three-unit fixed partial dentures made of lithium disilicate, alumina and zirconia. For three-unit restorations involving a molar, expert consensus suggests that only zirconia-based systems are indicated. CLINICAL IMPLICATIONS: Available evidence indicates the effectiveness of many all-ceramic systems for numerous clinical applications. Bonding has been shown to increase clinical success. Studies of zirconia prostheses indicate problems with porcelain cracking. (+info)
Fatigue cyclic loading test of an auro-galvanoforming ceramic bridge.
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BACKGROUND: In dental clinics, dentition defects are commonly restored with conventional porcelain-fused-to-metal fixed bridges. However, Ni-Cr alloy ceramic fixed bridges are known to have several drawbacks such as marginal coloration of the neck, low casting precision and, most seriously, poor biocompatibility. These problems could be circumvented by using noble metal ceramic bridges; however, one negative issue related to the conventional noble metal ceramic bridges is its high price due to the use of a large amount of gold for pontic. Therefore, an auro-galvanoforming ceramic bridge would be ideal to retain the advantages of a conventional material, yet reduce the amount of noble metal used. This study aimed to investigate whether any destructive changes occur to the auro-galvanoforming ceramic bridge under a fatigue cyclic loading test. METHODS: On standard models which the left maxillary first premolar is lost and with the cuspid teeth and the second premolar as the fixed bridge abutment teeth, six maxillary auro-galvanoforming ceramic bridges and six corresponding nichrome ceramic jointed crowns were made as group A, six nichrome ceramic bridges and six corresponding nichrome ceramic jointed crowns were made as group B (control group). And then all specimens were fixed and tested on a fatigue cyclic loading machine; the changes occurring to the surfaces of occlusal contact with large functional area and to the porcelain-metal interfaces of the nichrome primary copings margins were observed through a scanning electron microscope (SEM). RESULTS: In 120 hours' continual observation, none of the specimens had porcelain coating fractures or scraping occurrence and all of the porcelain coatings had been kept intact under sinusoidal cyclic loading with the load range of 120 - 200 N and frequency of 5 Hz. CONCLUSIONS: Auro-galvanoforming ceramic bridges exhibited excellent fatigue strength in the fatigue cyclic loading test and may satisfy the clinical demand in theory, while the practical application shall be evaluated by observations in long-term clinical usage. (+info)
Provisional repair of a zirconia fixed partial denture with fibre-reinforced restorative composite: a clinical report.
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Although all-ceramic restorations have become popular, they present some biomechanical problems. Some technical failures can be repaired intraorally to help maintain the longevity of the restoration. This clinical report describes an intraoral method for repairing a fractured 4-unit posterior zirconia-based ceramic fixed partial denture using fibre-reinforced composite material. (+info)