THE EFFECT OF RIDGE HEIGHT ON RETENTION OF ACRYLIC AND FLEXIBLE DENTURES IN PATIENTS WITH COMPLETE EDENTULOUS MAXILLARY ARCH: A PILOT STUDY

Introduction

Removable denture still stands as the preferred option in the management of completely edentulous arch in the developing society. The prosthodontist is challenged with providing a retentive denture to the patient, alleviating the effect of tooth loss. The retention of these prostheses is influenced by the material used for it fabrication and the edentulous ridge height, hence the need to assess the retention of acrylic and flexible complete denture and the effect of edentulous ridge height.

Aim

This study was to assess and compare the effect of ridge height on retention of flexible and acrylic complete upper dentures.

Materials and Methods

Ten patients with complete upper edentulous arches were recruited and randomly allocated into two groups (A and B). Acrylic and flexible, complete maxillary dentures were fabricated for each participant. Group A wore the acrylic denture first, while group B wore the flexible denture first. Each participant was recalled after using the denture for one week, one month, and three months for data collection.At cross over time (3 months after wearing the first denture), individuals in group A were given flexible dentures, while those in group B received acrylic dentures. The patients were recalled again for data collection by one of the researchers. Kapa Intra examiner reliability test was 83.3%. Information related to denture retention were obtained and entered into IBM SPSS software version 23 for analysis. Paired t-test and linear regression were used to test for association between quantitative variables. A P-value of 0.05 was regarded as significant.

Results

Ten individuals with mean age of 66.5±9.7 years and mean anterior ridge height of 15.5 ± 2.95 mm participated in this study. The subjective and objective assessments of the dentures showed that acrylic denture possessed a better retention than flexible denture. The effect of anterior ridge height on retention, showed a statistically significant difference (p= 0.006 for acrylic denture, p = 0.001 for flexible denture).

Conclusion

This study suggested that acrylic denture possesses better retention compared to the flexible type and far better in situation with lower ridge heights.

Newly designed retentive posts of mandibular reconstruction plate in oral cancer patients based on preliminary FEM study

BACKGROUND

The reconstruction of a large mandibular defect poses a challenging issue in oral cancer ablation surgery. One popular option for mandibular continuity reconstruction after tumor resection involves the use of a reconstruction plate (R-plate), which maintains space and contour without bone harvesting. An R-plate, however, cannot provide final functional loading rehabilitation with implants or dentures.

METHODS

We suggest a new method of functional mandibular reconstruction using retentive posts and an upper prosthesis. The finite element method (FEM) was used to optimize the design. Surgery was needed to adapt the retentive posts. Prosthodontic procedures were required for the upper prosthesis.

RESULTS

Eight patients were treated with retentive posts and prostheses. All patients underwent wide resections of the mandible, and reconstruction with an R-plate and microvascular soft tissue transfer. We adapted the retentive posts on an R-plate and fabricated the upper prostheses with a flexible denture or a fixed resin prosthesis. Finally, the patients had functional rehabilitation, which restored proper mastication.

CONCLUSIONS

The retentive posts of the R-plate and upper prosthesis allow functional dental rehabilitation without the need for a bone graft. Virtual simulation using FEM will help to design and optimize the retentive posts. Two or three regular size posts are suitable for the quadrant jaw. This first preliminary step will allow improved patient-specific retentive post designs in the near future.

Midline Fractures in Single Maxillary Complete Acrylic vs Flexible Dentures

BACKGROUND

Patients using single maxillary denture against their natural mandibular teeth face the problem of midline fracture in their routine acrylic dentures. Various techniques have failed over the years to address the problem. In this study, flexible denture material (Lucitone) with injection moulding system has been used and evaluated for midline fracture in these patients.

METHODS

A total of 58 patients in the age group of 38 to 80 years, who had experienced midline fracture in their acrylic maxillary dentures were selected. They were provided with new dentures using flexible denture material. Various parameters, namely, mastication, phonetics, esthetics and comfort level were evaluated.

RESULT

Only two cases reported slight crack in the palatal region of the-maxillary dentures after 18 months of use. Mastication and phonetics were found to be improved with flexible dentures.

CONCLUSION

The flexible denture is a promising material for preventing midline fractures in a single maxillary denture. It is well tolerated by the patients as compared to the methyl meth-acrylate dentures.