[Stress analysis of prosthodontics by finite element method]

Finite element stress analysis has been widely used in stomatology. In this article, we summarized the stress distributions of all-ceramic crowns, post crowns, fixed partial dentures and implant support fixed dentures; and with the use of finite element method, we investigated the stress levels of the periodontal ligament of abutment. The results showed: the tensile stress and compressive stress concentrated at the cervical margin of all-ceramic crown and post crown; the stress at the surface of the crown was the highest; the stress concentration exhibited at the connector of fixed parital denture, the molar was an ideal abutment tooth for the fixed bridge; the largest stress appeared around the neck of the implant abutment. These results have provided a theoretical basis for clinical dentistry in terms of restoration design and manufacture. It is suggested that clinical dentists should be careful to avoid the horizontal laoding applied on the prostheses so as to improve the resistance of abutment tooth to fracture.

Contemporary implant concepts in aesthetic dentistry--part 3: adjacent immediate implants in the aesthetic zone

This series of articles has discussed contemporary concepts in the treatment planning of dental implants in edentulous ridges and immediate single-tooth implants in the aesthetic zone. This presentation broadens the discussion to include the wider application of immediate implants, highlighting the surgical and restorative considerations affecting their immediate placement and provisionalization. It highlights the application of immediate implants in both single- and multiple-unit applications and provides detailed demonstrations of the involved implant and restorative components required by such procedures.

Future needs for fixed and removable partial dentures in the United States

STATEMENT OF PROBLEM

Because of the decline in missing teeth among most adults, prosthodontic advanced training programs are concerned about the need for prosthodontics in the future.

PURPOSE

An analysis was conducted to project the unmet need for fixed and removable partial dentures in the years 2005, 2010, and 2020.

MATERIAL AND METHODS

Unmet need was calculated as follows: Total need equals the number of persons in each age cohort multiplied by the percentage who need a fixed or removable partial denture multiplied by the average procedure time required to provide the service. Total unmet need then equals total need minus the annual supply of prosthodontic services delivered by prosthodontists and general practitioners.

RESULTS

Projected results indicate that total unmet need will increase from 488 million hours in 2005 to 517 million hours in 2010 and to 560 million hours in 2020.

CONCLUSION

The significance of the results is that unmet prosthodontic need will increase and exceed the supply of services for the foreseeable 20-year future. Practicing dentists will find that a sizable minority of the population will continue to need fixed and removable partial denture services.

Changes over time in the clientele and restoration pattern in a dental school prosthodontic department

The clientele and the production of single artificial crowns and fixed partial dentures in the Department of Prosthodontics were compared from 1964/68-1982/87. In the first period 65 per cent of the single crowns were made for women versus 55 per cent in the second. In the first period 69 per cent of the crowns were placed in the upper jaw as against 60 per cent in the second period. On average 1.6 crowns were made per female patient in the first period versus 1.4 per male patient. In the second period both sexes averaged 1.8 units. In both jaws the percentage of root-filled crowned teeth had increased in the second period to 60 per cent from 48 per cent in the upper jaw and 46 per cent in the lower jaw. In both sexes maxillary and mandibular teeth were crowned on average 13 years later in the second period than in the first. Sixty per cent of the fixed partial dentures were made for women in the first period versus 55 per cent in the second. In the first period 74 per cent of the bridges were made for the upper jaw as against 70 per cent in the second period. The mean pontic to abutment ratio was 0.7 in both periods. The maximum number of bridges in the first period were made for patients 40-59 years of age versus 50-69 years in the second period.(ABSTRACT TRUNCATED AT 250 WORDS)