Pair Of Dentures Research Articles

Complete denture replacement: a 20-year retrospective study of adults receiving publicly funded dental care.

There is little evidence as to what is the appropriate replacement interval for complete dentures. The aim of this study was to determine the longevity of complete dentures in a population of publicly insured adults across a 20 year observation period. The records of 187,227 Australian adults who accessed complete denture treatment through public clinics between 2000-2019 were assessed. Time to denture replacement was modelled using a Weibull regression and a competing risk regression to adjust for the competing risk of mortality. Over a 20-year period, 27.7% of dentures were replaced, with a mean longevity of 6.06 (SD: 3.93) years. Pairs of complete dentures had greater mean longevity than single dentures (p<0.001). Approximately 4.6% of dentures provided were replaced within 2 years; 18.4% were replaced between 2 and 10 years and 4.6% of replacements occurred after 10 years.Over 70% of adults who received a complete denture did not replace it during the observation period. Dentures provided by denturists had higher levels of replacement than those made by dentists. Participants over 80 years of age had lower rates of denture replacement. Low socio-economic status and living outside a major city were associated with reduced rates of replacement for dentures under 10 years of age. Complete dentures were commonly replaced after 6 years of service. Pairs of dentures lasted longer than single dentures.

Accuracy of digitally fabricated trial dentures

Statement of problemInformation about the accuracy of digital computer-aided design and computer-aided manufacturing (CAD-CAM) complete dentures is scarce. PurposeThe purpose of this in vitro study was to assess the reproducibility of the occlusion of wax dentures fabricated with digital steps and the contraction behavior of wax trial dentures processed with combined conventional-digital steps. These were compared with those fabricated completely conventionally in terms of storage duration. Material and methodsFive sets of maxillary and mandibular wax trial dentures were milled from a gingiva-colored wax blank (Ceramill D-Wax, Amann Girrbach AG) using the Ceramill Motion 2 System (Amann Girrbach), scanned, and matched by best-fit triangulation for each of the 5 denture pairs. Processing deformation was measured and the maximum deviations calculated. A 3-dimensional color-coded mapping of the differences between each pair of dentures was generated. Five sets of maxillary and mandibular wax trial dentures were processed with digital steps, and 5 sets of maxillary and mandibular wax trial dentures were fabricated in the conventional way with the help of a silicone index from a CAM-fabricated wax trial denture to standardize the wax amount. All dentures were scanned immediately after waxing and after 1 week of storage. After surface matching, the deformation was measured, and the milled wax bases were compared with those conventionally fabricated. Data were interpreted using descriptive statistics. ResultsThe occlusion of wax trial dentures fabricated with digital steps was not reproducible. The deviations in the maxillary dentures were mostly marginal, with exceptions for single teeth/tooth groups in denture No. 2 (occlusal areas of teeth in second quadrant, second molars) and No. 4 (central incisor and canine in second quadrant inclined to palatal side, and first premolar in first quadrant and first molar in second quadrant displayed greater deviations). Among the mandibular dentures, denture Nos. 4 and 5 the central incisor (fourth quadrant) inclined to the labial side. Additionally, in denture No. 5 the lateral incisor (fourth quadrant) inclined to the lingual side. ConclusionsIn digitally fabricated dentures, the manual placing of the teeth into the denture base sockets can lead to deviations from the planned arrangement. The deviations were greater in the area of the denture bases in the conventionally fabricated dentures compared with those processed with combined conventional-digital steps. The milled wax bases showed better contraction behavior than the conventionally fabricated wax bases.

A Comparison of the Change in Mandibular Condyle/Fossa Relationship with the Use of Anatomic Teeth and Semi-anatomic Teeth in Complete Denture Prosthesis

The association between dental occlusion and mandibular condyle/fossa relation has long been debated and still remains one of the most controversial issues in Prosthodontics. The aim of the study was to evaluate the effect of two different tooth forms on the condyle/fossa relation recorded during jaw relation process. Twenty edentulous patients were selected with good neuromuscular control. For each patient two pairs of dentures were fabricated with anatomic teeth and semi-anatomic teeth. Condylar position was recorded using a digital volume tomography (DVT) following the process of jaw relation (following extra oral tracing). Subsequent laboratory remounting, the denture insertion was done and DVTs were taken again for both the dentures separately. Two methods were used to evaluate the condyle/fossa relation viz. (1) Zhang's method (2) Brewka's method. The obtained values were then subjected to statistical analysis. The statistical significance was set as at 0.05%. The mandibular concentricity were analysed during the process of jaw relation and after the insertion of dentures with the two different tooth forms. Statistical analysis indicated that no statistically significant difference of the influence of different posterior tooth forms on the condyle/fossa relation recorded during jaw relation (p<0.05). Thus within limitations of this study it was concluded that the condyle/fossa relation established during jaw relation does not change with the change in posterior tooth form used.

Oral health status of elderly hospitalised psychiatric patients

This study investigated the oral health status of an elderly mentally ill population hospitalised in a psychogeriatric ward in Athens. A structured interview recorded sociodemographic and dental data, and an oral examination recorded the status of oral tissues and the existing dentures. The patients' medical records were examined by a hospital's physician. One hundred and eleven patients with a mean age of 73 years participated in the study. Almost half of them suffered from schizophrenia. Forty percent were completely edentulous but only 38.6% of them used a pair of dentures. The dentate had an average of 12.9 teeth, 50.7% of them had at least one decayed tooth, 44.8% needed at least one extraction, and only 26.7% had filled teeth. The dental hygiene was poor in 83.6% of the patients. More than 60% of the dentures had a defect. Multiple regression analyses showed that increasing age and dementia were significantly related to fewer remaining teeth, and the use of atypical antipsychotics was related to fewer caried teeth. The oral health of the elderly psychiatric patients was very poor. Access to dental care should improve, and the health care staff should be trained to identify oral problems.

The influence of double flask investing on tooth displacement in dentures processed by microwave irradiation

This study evaluated the influence of the bimaxillary flask (BMF) and two different investing materials on first molar inclination in dentures processed by microwave irradiation. The BMF may minimise tooth displacement, saving time and improving occlusion. Forty pairs of dentures were randomised into four groups: stone wall in monomaxillary flask; silicone wall in BMF; stone wall in BMF; acrylic resin retentions and silicone in BMF. Dentures were processed by microwave irradiation. Two referential points were established on tooth surface. A microscope and a digital pachymeter were used to measure the distance between these points, and the angles α (right maxillary molar), β (left maxillary molar), α' (right mandibular molar) and β' (left mandibular molar) were calculated by the law of cosines. Data were submitted to Kruskal-Wallis (5% significance). No difference was observed among the groups (p > 0.05). In the intra-group analysis, α was significantly different for groups I, II and III; α', for groups II and IV; β, for all groups; β', for groups III and IV. First molar inclination was similar for monomaxillary and BMFs. The use of stone or silicone as investing materials presented the same effect on tooth inclination.