Agreement between self-rated denture condition and clinical examination in older adults

OBJECTIVES

This study aimed to compare differences between complete denture conditions self-rated by older adult wearers and clinically exanimated by a professional based on standardised aesthetics and functional criteria.

MATERIALS AND METHODS

Complete denture clinical examination was based on the functional (stability, retention, occlusion and articulation, vertical dimension of occlusion) and aesthetics criteria. Data on self-rated complete denture conditions were measured using the Patient's Denture Assessment (PDA) questionnaire based on standardised aesthetic and functional criteria (n = 122). Prevalence rates of clinical and self-rated complete denture condition, sensitivity, specificity, positive and negative predictive values, and absolute and relative bias were calculated.

RESULTS

The highest sensitivity (66.7% [95% CI 55.3-76.7]) was obtained for aesthetic criterion, whereas occlusion revealed the lowest sensitivity (14.9% [95% CI 6.2-28.3]). Stability had the highest specificity (91.3% [95% CI 72.0-98.9]) and aesthetics the lowest (21.4% [95% CI 8.3-41.0]). Stability also yielded the highest positive predictive value (83.3% [95% CI 51.6-97.9]), and vertical dimension of occlusion the lowest (26.3% [95% CI 9.1-51.2]). The vertical dimension of occlusion yielded the highest negative predictive value (71.2% [95% CI 58.7-81.7]). Self-rated data underestimated the complete denture condition in 6.5% compared with clinical examinations when the aesthetic criterion was excluded from the analysis and 7.6% when added.

CONCLUSIONS

Older adult wearers better identified the condition of their complete denture when the aesthetic criterion was excluded from examination. In contrast, considering functional criteria (retention, stability, occlusion and vertical dimension of occlusion), self-rated complete denture conditions underestimated clinical examination.

CLINICAL RELEVANCE

Using standardised aesthetic criteria in epidemiological studies for assessing complete denture conditions self-rated by wearers could avoid underestimating or overestimating the information regarding the use or need for dental prostheses.

A Novel Design to Optimize Biomechanical Properties of Dental Implant

Objective: The main objective of this study is to evaluate a novel design to optimize dental implant biomechanics. According to this objective, evaluations of the resilient implant design which aimed to mimic biomechanical behaviors of natural tooth have been made and outcomes were compared with natural tooth and standard dental implants with using 3D hyper-elastic finite element analysis. Methods: Models used in the study corresponding to conventional dental implant, natural tooth and resilient dental implant design. Hyperelastic model analysis were performed for close presentment of mechanical behaviors of resilient materials like periodontal ligament and medical silicone. Top values of maximum principal stress, minimum principal stress of surrounding bone and displacement of each model were evaluated under axial and non-axial loading conditions with magnitude of 30N, 80N and 100N. Results: Outcomes of finite element study showed reduction on maximum principal stress and minimum principal stress levels with the use of resilient dental implant comparing to the standard implant model. Standard implant model had been observed notably rigid in all loading conditions compared to the other models. Resilient implant model showed similar biomechanical characteristics with natural tooth model within the limitations of this study. Conclusion: According to finite element analysis results; resilient implant design was able to resolve some biomechanical discrepancies and seem to have adequate biomechanical similarity with natural tooth under both axial and non-axial loading conditions.

Effect of Number and Location on Stress Distribution of Mini Dental Implant-Assisted Mandibular Kennedy Class I Removable Partial Denture: Three-Dimensional Finite Element Analysis

Purpose. To investigate effects of number and location on patterns of von Mises stress distribution and volume average stress on abutment tooth, edentulous ridge, mini dental implant, and surrounding bone of mini dental implant-assisted mandibular Kennedy class I removable partial denture. Materials and Methods. Eight three-dimensional finite element models of mandibular Kennedy class I with different numbers and locations of mini dental implants were constructed. Mini dental implants were generated in the area of second premolar, first molar, and second molar, respectively. A static load of 400 N was applied on all models. The von Mises stress and volumetric average stress were calculated by three-dimensional finite element analysis. Result. The minimum volumetric average stress of abutment tooth was found in the model, where there was one mini dental implant at the second molar position and 2 mini dental implants at first molar and second molar positions. The model with three mini dental implants had reduced volumetric average stress of abutment tooth, which was not different from the model with two mini dental implants. However, the minimum volumetric average stress of mini dental implant and surrounding bone were found when three mini dental implants were applied, followed by two and one mini dental implants, respectively. Conclusion. Placing at least one mini dental implant at a second molar position can help reduce stress transferred to the abutment tooth. Stresses around each implant and surrounding bone reduced with increased numbers of mini dental implants.

Strength of Polyether Ether Ketone Composite as a Major Connector Material for Removable Partial Dentures

PEEK composite was tested mechanically as a maxillary removable partial denture (RPD) framework material instead of cast cobalt chromium alloy. Methods: Partial edentulous upper jaw cast was scanned using structured-light 3D scanner, palatal strap (PS) designs for RPD were designed by a designing dental laboratory software. CAD/CAM machine fabricated PSs patterns using their designs’ STL software files. PSs were made from poly-ether-ether ketone (PEEK) reinforced by ceramic fillers using thermal injection press technique and Co-Cr alloy using centrifugal casting, each material group was subdivided into two subgroups according to storage conditions (stored and non-stored subgroups), storage took place in deionized water for about 180 days at 37.5 ± 2 o C. All specimens were subjected to fracture resistance test using universal testing machine then maximum compression load (MCL) result values were subjected to statistical analysis. PEEK composite specimens were scanned by field emission microscope (FEM) and energy dispersive spectroscopy. Storage water of PEEK composite was analyzed using atomic absorption spectroscopy (AAS). Results: In either stored or non-stored subgroups of PEEK composite straps they showed significant lower mean MCL values than corresponding alloy subgroups (p=0.0001). FEM scanning showed fillers agglomerations in non-stored PEEK composite and their nearly absence from stored PEEK composite specimens. AAS detected Al element in PEEK composite storage water. Conclusion: Mechanically thermally injected ceramic reinforced PEEK composite could not replace cast Co-Cr alloy as PSs material for maxillary RPD. Biocompatibility concerns raised in this study due to suspected Al leaching and ceramic fillers dissolution from PEEK composite matrix.

Repercussion of Conventional Complete Mandibular Denture Versus Single Implant Over-Denture on Retention and Biting Force

Aim: Aim of this study was the evaluate the retention and biting force of conventional complete denture and after placement of a single implant in the mandible for an implant retained over-denture Material and methods Eight completely edentulous patients were selected. A single implant was inserted at the symphysis of the mandible and left to osseointergrate. During the osseointegration period a conventional complete denture was fabricated and inserted. Retention and biting force was measured at insertion and after 3 months of service. After osseointegration attachment was connected, space was formed in the fitting surface of the existing mandibular denture and retention silicon was placed. Retention and biting force were measured at insertion and after 3 months follow-up. Data were collected and statistically analyzed. Results: The retention mean values for the complete denture was 2.420±0.360, however the retention mean values for the single implant over-denture was 6.395±0.289.  F=3.80 with statically significance difference between the groups of P <0.01. The biting force mean values for the complete denture was 52.62±2.71, however the biting force mean values for single implant over-denture was 71.45±2.73. F= 1.790 with statically insignificance difference between the groups of P >0.01 Conclusion: Single implant overdenture improved the retention and the biting force when compared with the complete denture, this has improved the quality of life and happiness.

Functional and psychological evaluation of premenopausal and postmenopausal women after provision of a complete denture prosthesis

STATEMENT OF PROBLEM

Clinical studies regarding satisfaction and occlusal forces with the complete denture in relation to the menopause are sparse.

PURPOSE

The purpose of this clinical study was to compare satisfaction levels and occlusal force with complete dentures in premenopausal and postmenopausal Indian women.

MATERIAL AND METHODS

Twenty premenopausal (group pre-MP) and 20 postmenopausal (group post-MP) completely edentulous participants were selected based on inclusion and exclusion criteria, and estradiol levels were measured. Complete dentures were delivered to all participants following standard fabrication and insertion protocols. Three months after denture insertion, when participants were free of postinsertion complaints, satisfaction level (by using a valid and reliable questionnaire), depression level by using the Patient Health Questionnaire, (PHQ-9) and occlusal force (with a gnathodynamometer) were measured. The obtained data of all parameters were tabulated and compared by using a statistical software program (α=.05).

RESULTS

For questions pertaining to the overall satisfaction of maxillary and mandibular dentures, the 2 study groups encountered a significant difference with the premenopausal group showing significantly higher satisfaction levels (P<.001). Depression scores in the postmenopausal women group were significantly higher than those of the premenopausal women group (P<.001). A negative correlation was found between the overall satisfaction with complete dentures and depression levels in the participants indicating decreased overall satisfaction with increasing depression levels in participants (rho=-0.698). The premenopausal group recorded significantly higher estradiol levels than the postmenopausal group (P<.001). Mean occlusal force with complete dentures in the premenopausal women group was significantly higher than that of the postmenopausal women group (P<.001). A positive correlation was found between the estradiol levels and occlusal forces in the participants indicating that with decreasing estradiol levels, the occlusal forces decrease in the participants (r=0.740).

CONCLUSION

Satisfaction levels and occlusal force with complete dentures were significantly higher in premenopausal women group than in the postmenopausal group.

Stress analysis of mandibular implant overdenture with locator and bar/clip attachment: Comparative study with differences in the denture base length

PURPOSE

The design of the attachment must provide an optimum stress distribution around the implant. In this study, for implant overdentures with a bar/clip attachment or a locator attachment, the stress transmitted to the implant in accordance with the change in the denture base length and the vertical pressure was measured and analyzed.

MATERIALS AND METHODS

Test model was created with epoxy resin. The strain gauges made a tight contact with implant surfaces. A universal testing machine was used to exert a vertical pressure on the mandibular implant overdenture and the strain rate of the implants was measured.

RESULTS

Means and standard deviations of the maximum micro-deformation rates were determined. 1) Locator attachment: The implants on the working side generally showed higher strain than those on the non-working side. Tensile force was observed on the mesial surface of the implant on the working side, and the compressive force was applied to the buccal surface and on the surfaces of the implant on the non-working side. 2) Bar/clip attachment: The implants on the both non-working and working sides showed high strain; all surfaces except the mesial surface of the implant on the non-working side showed a compressive force.

CONCLUSION

To minimize the strain on implants in mandibular implant overdentures, the attachment of the implant should be carefully selected and the denture base should be extended as much as possible.