Types Of Denture Teeth Research Articles

Colour Stability of Different Denture Teeth Stored in Various Beverages

Aim: New types of denture teeth using modified acrylic resin that incorporate cross-linking agents and composite resin containing different types of filler have become increasingly common. It has been possible to produce nano-sized filler particles with nanotechnology. However, evidence-based information regarding composition and properties is lacking. The purpose of this study was to evaluate the colour stability of four commercially available denture tooth materials with different chemical structure when subjected to various beverages.
 Methods: Conventional acrylic resin, reinforced acrylic resin, microfiller composite resin, and nanofiller composite resin teeth with different brands were used, for a total of four different denture teeth groups. Denture teeth were subjected to four beverages (tea, filtered coffee, cola, and cherry juice) and distilled water as control. The test period of 24 hours appears comparable to approximately 1 month of normal beverage consumption. The test periods used in this study were arranged according to this protocol and 1 week, 1 month, 3 months and 6 months of normal beverage consumptions were simulated. From each group, 10 maxillary first molar denture teeth were immersed in each of the five solutions. The baseline, 1st week, 1st month, 3rd month and 6th month values for colour change of denture teeth were measured. 
 Results: The differences of each value were calculated by one-way ANOVA statistically. For colour changes (ΔE) there was no significant difference among the specimens immersed in distilled water (Tukey HSD test, p>0.01). The highest colour changes were recorded for the specimens of Integral and Major immersed in cola, whereas for the specimens of Veracia and Orthosit immersed in tea (Tukey HSD test, p

Precision and accuracy of digital smile analysis in removable complete denture

Background/aim Digital Smile Design (DSD) software is a beneficial approach to the potential of patient smile enhancement by producing an esthetic treatment plan. This study aimed to evaluate the precision and accuracy of hand calibrated, photo analysis, and DSD method in removable complete dentures and correlate them with different types of denture teeth. Patients and methods This study was conducted on 29 completely edentulous patients selected from the Outpatient Clinic of Prosthodontic Department, Faculty of Oral and Dental Medicine, Badr University, Egypt. Each patient received two sets of complete dentures as follows: the first denture was constructed from a conventional complete denture with cross-linked resin teeth and served as the control group (group I), and the second denture was constructed from conventional complete denture with nanohybrid composite teeth and served as the test group (group II). Each group was further subdivided into three subgroups, according to the different smile analysis techniques performed: subgroup A, hand calibrated method; subgroup B, photo analysis method, and subgroup C, DSD method. Then, precision and accuracy were evaluated for each smile variable. Results Mean absolute difference was calculated between group I and group II for each smile analysis technique, revealing that the least amount of difference between groups was illustrated in the subgroup A followed by subgroup C and finally subgroup B, which revealed the maximum amount of difference between groups ranged from 0.0031 to 0.2623. Cronbach's Α was calculated for group I and group II between each smile analysis technique, revealing that all was less reliable (less accurate), except lower teeth exposure in group II was rather reliable (rather accurate) ranging from 0.023 to 0.784. Conclusion With the respect to limitations of this study regarding individualized anatomical variations and distortion liability of the image, it was concluded that nanohybrid resin composite denture teeth had less deviation (higher precision) than the conventional acrylic resin denture teeth regarding the ratio of different smile parameters with facial proportions.

Optical and mechanical properties of conventional, milled and 3D-printed denture teeth

ObjectivesInvestigate the effect of various liquids on the optical properties and Vickers hardness of conventional, milled and 3D-printed denture teeth. MethodsSix different types of denture teeth (Maxillary anteriors of three different conventional teeth, Vivodent DCL, SR Phonares II, Vita Physiodens; milled teeth, IvotionDent; and two different 3D-printed teeth, Asiga DentaTooth and NextDent C&B MFH) were investigated (total n = 336). The labial surface of each specimen was prepared to a dimension of 10 × 5 × 3mm. Specimens were immersed in artificial saliva, coffee, red wine and denture cleaner with artificial aging to simulate denture use of 12 and 24 months in vivo. Measurements of translucency parameter (TP), shade change (ΔE), surface roughness (Ra) and Vickers hardness (VHN) were conducted at baseline and after artificial aging while immersed in the liquids at each timeframe. Data were statistically analysed by ANOVA and post-hoc test (SPSS Ver 27). Surfaces of specimens were analysed under scanning electron microscopy (SEM). ResultsMilled teeth had the highest overall translucency parameter (5.33 ± 0.76–7.3 ± 0.99). All materials had statistically significant change in translucency parameter and shade after 24 months simulated aging (p < 0.05), especially the milled and 3D-printed teeth (p < 0.01). Surface roughness of all materials were under plaque accumulation threshold Ra = 0.2 μm. At baseline, Vita Physiodens teeth (PMMA with microfillers) demonstrated the highest hardness (33.99 kgf/mm2±3.7), whereas both 3D-printed materials exhibited the lowest hardness (13.27 kgf/mm2±0.36–18.13 kgf/mm2±0.93). Artificial saliva, red wine and denture cleaner had a statistically significant impact (p < 0.05) on hardness of all materials (12.1 kgf/mm2±1.17–30.77 kgf/mm2±2.98). ConclusionsMilled teeth exhibited the best optical properties (highest overall translucency parameter and lowest shade change). Milled teeth were also the only material that showed colour change (ΔE values) within clinically acceptable limits. Denture cleaner had the most impact on optical and mechanical properties of all materials. Surface roughness and hardness of 3D-printed teeth had the most change after artificial aging.

Comparative Effect of Different Surface Treatments on the Shear Bond Strength of Two Types of Artificial Teeth Bonded To Two Types of Denture Base Resins.

This in vitro study aims to assess the impact of various surface treatments on the shear bond strength (SBS) of two types of artificial teeth and denture base resins (DBRs). Two types of DBRs (CAD/CAM-milled and heat-polymerized) and two types of denture teeth (acrylic and composite) were investigated. Teeth were cut into slices (5 × 5 × 2 mm) and divided according to surface treatment into four subgroups (n = 10): no treatment (control), air abrasion (Alumina-blasting; AB), bur roughening, and dichloromethane (DCM) subgroups. According to manufacturer recommendations, the treated tooth slices were bonded to the acrylic disk of DBRs. The SBS test was performed using a universal testing machine. ANOVA was used for results analysis followed by Tukey's post hoc tests (α = 0.05). DCM and AB increased the SBS of acrylic teeth to heat-polymerized DBR compared with other groups (p < 0.001). All surface treatments showed no significant difference in CAD/CAM DBR with acrylic teeth (p = 0.059; AB, p = 0.319; bur roughening, p = 0.895; DCM), while there was a significant decrease in SBS with composite teeth (p ˂ 0.001). Between teeth, acrylic teeth showed a statistically significant increase in SBS compared to composite teeth (p < 0.001). AB and DCM application improved the SBS for acrylic teeth with the heat-polymerized DBR when compared with the untreated group, but none of the surface treatment agents showed significant improvement with CAD/CAM DBR. All surface treatment agents reduced the SBS for composite teeth with CAD/CAM DBR while AB only increased the SBS with heat-polymerized DBR.

What Occlusal Scheme Should Be Used with Removable Partial Dentures?

Multiple clinical studies have been published comparing different philosophies of complete denture occlusion and different types of denture teeth. However, it is unclear whether comparable data are available for occlusal schemes used with removable partial dentures (RPDs). Therefore, this review investigated the dental literature related to occlusal schemes for RPDs. A PubMed search of English language articles was performed using the term "removable partial denture, occlusion" with 765 results. When the term "occlusion in removable partial prosthodontics" was used there were 784 results. Seventy-four articles were identified using the different search term of "RPD, occlusion" while use of the term "occlusal scheme, with removable partial dentures" listed 18 publications. The term "removable partial denture, occlusion, literature reviews" produced 38 potential publications related to the topic. Using the term "removable partial denture occlusion systematic review" resulted in 2 citations. Using the term "RPD occlusion literature review" resulted in one foreign language manuscript whereas using the term "RPD occlusion systematic review" resulted in one article unrelated to dentistry. The term "clinical studies of RPD occlusion" produced 5 results with none related to the topic. There were 23 results using the term "clinical studies of removable partial denture occlusion" with one potentially related to RPD occlusal schemes. A review of the titles and abstracts revealed 12 articles that appeared to contain specific information about the occlusal scheme used with RPDs. Following a detailed review of those publications, only 4 contained recommendations for RPD occlusion and were included in this review. The available information regarding the recommendations for occlusal schemes in these articles was based on expert opinion. A decision was made to include a hand search of 9 textbooks containing varying amounts of information related to occlusal schemes for RPDs, but no evidence-based references related to RPD occlusal schemes were found in the textbooks. Since this entire review is based on expert opinion, no attempt was made to critique the opinions expressed by these authors but rather to present their perspectives for evaluation by readers. The occlusion developed with RPDs should be physiologically harmonious, allowing the supporting structures to remain in a good state of health with functional stress distributed among all the occluding teeth. Multiple authors indicate the occlusion in maximum intercuspation/centric occlusion should incorporate bilateral posterior contacts with no deflective occlusal contacts. When most occlusal contacts on natural teeth are missing, it has been proposed that extension base RPDs have their occlusal contacts developed in centric occlusion. Regarding eccentric occlusal relationships, a balanced occlusal scheme has been recommended by multiple authors with one author advocating use of a lingualized balanced. An anterior guided (canine-protected) occlusion has also been recommended when the canines are present and not periodontally compromised. When RPDs oppose a complete denture, several authors indicate a bilateral balanced occlusion should be used to help stabilize the complete denture.

Effect of glass-fiber usage on bond strength of acrylic resin to components of removable partial denture

Aim: In order to improve the mechanical properties of polymethyl methacrylate (PMMA), more attention has been directed toward the glass fibers due to its good reinforcement capability. The purpose of this study was to determine the effect of glass fibers on the bond strength between reinforced acrylic resin and components of removable partial denture (RPD). Materials and Methods: Two types of denture teeth (conventional resin and cross-linked resin), two types of framework alloys (CoCr and Ti6Al4V) and heat-polymerized acrylic resin that was not reinforced and reinforced with glass fiber content of 1% and 5% were used. Reinforced and unreinforced acrylic resins were applied to both denture tooth and framework alloy samples to construct bonding area as 5 mm diameter. After polymerization of acrylic resin, samples were stored in distilled water for 2 days at 37°C; then they were thermocycled 5000 times (5-55°C). To record shear bond strength of samples, universal testing machine was used until failure occurred. The shear bond strength data were analyzed at 5% significance level. Results: The shear bond strength of CoCr alloy and cross-linked resin denture tooth samples didn't show any effect with reinforcement. But conventional resin denture teeth bonding enhanced with 5% fiber concentration; and Ti6Al4V, the addition of glass fiber, regardless of the ratio, affected the bonding strength in a positive way. Conclusions: Glass fiber reinforcement of the PMMA increased or did not aAQ4ffect, but never decreased the bonding strength between acrylic resin and component of RPD.

EFFECT OF DENTURE CLEANSERS ON THE COLOR STABILITY OF DIFFERENT DENTURE TEETH MATERIALS

Objectives: Denture cleansers are commonlyused for cleaning partial and complete dentures.The purpose of this in vitro study was to evaluatethe effect of denture cleansers on color stability ofconventional acrylic, reinforced acrylic andporcelain denture teeth materials.Materials and Methods: Maxillary centralincisors in A2 color were used from three types ofdenture teeth (n=10). Denture teeth kept in distilledwater were considered as control group. Testspecimens were immersed in denture cleansers,which prepared according to the manufacturersinstructions. Color measurements were performedbefore immersion of cleansers, after 1 week andafter 3 weeks with a colorimeter. Color changes(ΔE) of the specimens were calculated and theresults were compared statistically with three wayANOVA.Results: Significant differences were found onthe color changes of denture teeth after 1 week and3 weeks of the immersion of denture cleansers(p<0,05). Also ΔE values were increasedsignificantly with time (p<0,05). The lowest ΔEvalues were observed in distilled water. The lowestΔE values were observed in porcelain teeth in alldenture cleansers (p<0,05). Color changes ofconventional acrylic and reinforced acrylic teeth inall denture cleansers after 3 weeks were acceptable.Conclusions: The greatest color change wasobserved in conventional acrylic resin teeth,reinforced acrylic and porcelain teeth, respectively,after immersion of denture cleansers.

A Comparison of Acrylic and Multilithic Teeth Bond Strengths to Acrylic Denture Base Material

Debonding of denture teeth from the denture base can be frustrating for both the clinician as well as his or her patients. The wear resistance of composite denture teeth has been well investigated since their introduction, but there have been few studies about the bonding of these teeth to acrylic denture base resins. The aim of this study was to compare the bond strengths of two brands of acrylic and one brand of multilithic denture teeth to acrylic denture base material. In this experimental-laboratory study, three types of denture teeth--Yaghoot, Super Brilian, and Major--were used. After grinding the glossy ridge lap surfaces, the teeth were mounted on two sides of triangular-shaped wax models. Then the wax elimination and resin processing laboratory procedures were carried out as is done with the fabrication of a complete denture. Each of the specimens was tested using a universal testing machine with a cross head speed of 5 mm/min at an angle of 130 degrees to the long axis of the teeth. The data were analyzed using one-way ANOVA and Chi-square tests. The mean bond strength in the Yaghoot group was 717.43+/-293.59 N while in the Super Brilian group it was 578.40+/-395.38 and in the Major group, 547.95+/-296.75N. However, there was no significant difference between the three groups (p=0.194). Although the mean bond strength in the multilithic group was higher than in the other groups, no significant difference was found between the three groups. There was no significant difference between the three groups with regard to the prevalence and type of fracture site. The bonding strength of multilithic denture teeth to denture base resins was found to be comparable to, and even slightly higher than, acrylic conventional denture teeth, making them a promising choice for clinicians in the fabrication of removable dentures.

Wear of feldspathic ceramic, nano‐filled composite resin and acrylic resin artificial teeth when opposed to different antagonists

The aim of this study was to evaluate the wear of denture teeth and their antagonists produced by two-body and three-body wear tests. Three types of denture teeth, namely feldspathic ceramic (FC), nano-filled composite resin (NCR), and experimental acrylic resin teeth (AR), were tested. For each type two groups of eight upper premolars each were prepared. The first group was tested against cusps from the same material and the second group was tested against human enamel cusps. Each group was loaded with a total of 200,000 chewing cycles (two-body wear 100,000 cycles and three-body wear 100,000 cycles). Wear was analyzed by measuring the maximum depth and volume loss of the denture teeth using a laser scanner and by measuring the vertical loss of the antagonists using an optical macroscope. Statistically, there was no significant difference between the following combinations: FC-FC and NCR-NCR regarding the vertical and volume loss; and FC-enamel and NCR-enamel regarding the total vertical substance loss. The combinations AR-AR and AR-enamel showed higher wear values than the other combinations. For complete dentures, composite resin and ceramic teeth showed similar vertical and volume loss, whereas composite resin teeth seemed to be more suitable for partial dentures opposing natural teeth in terms of wear of teeth and antagonists.

In Vitro Wear of Nano‐Composite Denture Teeth

Few laboratory tests have been able to substantiate and quantify the wear resistances of polymeric denture teeth. This study evaluated the relative wear resistance of several types of denture teeth using an in vitro wear testing device. Four different types of denture teeth [nano-filled (Veracia) and micro-filled composites (SR-Orthosit, Endura, Duradent, Surpass), cross-linked acrylic (SR-Postaris, Genios-P, Creapearl, Vitapan Physiodens, Premium 8, Integral), and a conventional acrylic (Biotone)] were used. The flattened buccal surface of each denture tooth was subjected to the evaluation of Knoop hardness (n=5) and localized wear for 100,000 cycles (n=10). Wear values were determined in micrometers using a profilometer. The data for the hardness, wear depth, and worn surface areas were individually analyzed by one-way ANOVA. Knoop hardness values (KHN) ranged from 28.2 to 29.8 for micro-filled composite, 18.9 to 21.6 for cross-linked acrylic, 22.7 for nano-composite, and 18.6 for conventional acrylic teeth. All micro-filled composite teeth were significantly harder than other teeth (p <0.0001). The wear depth values were 90.5 microm for the nano-composite, 69.8 to 93.0 microm for the micro-filled composite, 80.8 to 104.0 microm for the cross-linked acrylic, and 162.5 microm for conventional acrylic teeth. The worn surface areas were 5.1 mm2 for the nano-composite, 2.6 to 3.6 mm2 for the micro-filled composite, 4.4 to 5.7 mm2 for the cross-linked acrylic, and 10.1 mm2 for conventional acrylic teeth. The wear values of the acrylic control were significantly different from all other denture teeth (p <0.001). The nano-composite tooth was harder and more wear resistant than the acrylic teeth but not significantly different from most of the cross-linked and micro-filled composite teeth tested.

Twelve-month results of a clinical wear study of three artificial tooth materials

This study compared in vivo wear of a new artificial tooth material with that of existing artificial tooth materials. Artificial tooth wear was determined by measuring height changes of selected points on contacting tooth surfaces in patients with complete dentures during a 12-month period. These results are part of an ongoing 3-year clinical study. A total of 67 patients were randomized to one of three treatment groups in this double-blind study. Group 1 received dentures with existing artificial tooth materials. Group 2 received dentures that contained teeth with the new experimental material. Group 3 received dentures with Bioform IPN resin teeth (Dentsply International Inc., York, Pa). A computerized coordinate measuring machine and computer-controlled X-Y positioning stages were used for this study. Tooth wear was determined by measuring vertical heights of contacting points from baseline points at each of two time intervals. The calculation of wear was made by comparing the differences in height at the beginning of the experiment with those measured at each time interval. A repeated measures analysis of variance (ANOVA) was used to test the difference in mean wear among the three groups from baseline to 6 months and from 6 to 12 months. Group differences in total wear at 12 months were also tested. The ANOVA results revealed no statistically significant differences in the wear among the three types of denture teeth at the 6- or 12-month time intervals or at 12 months (p > 0.05). The average total wear value at 12 months was 90 microns. Group 1 averaged 102 microns of wear, group 2 averaged 88 microns of wear, and group 3 averaged 76 microns of wear.

義歯床用流し込み型レジンと硬質レジンの結合耐久性について

Factors affecting bonding durability between three types of denture teeth (two abrasion-resistant plastic denture teeth and a plastic denture tooth) and a pour-type denture base resin were investigated. The bond strengths of Duradent (DU) and Real Crown (RE) were not affected by a water immersion period for up to one week, but significantly decreased after being immersed for one month. Endura (EN) showed a stable bond strength up to one month immersion. Thermocycling (500 cycles) also decreased the bond strengths for all denture teeth. The bond strengthsof Dichloromethane-treated denture teeth did not change even with one month immersion or thermocycling. The results of this investigation suggested that the treatment with Dichloromethane significantly would improve the bonding durability.

Bond strength and failure analysis of light-cured denture resins bonded to denture teeth

This study examined the tensile bond strength and failure sites of one heat-cured (Microlon) and two visible light-cured (Triad and Extoral) denture resins to two types of denture teeth. The resins were processed into cylinders against denture teeth milled to the same size. Half of the specimens were thermocycled. After tensile testing, statistical analysis ( p 0.05) showed that the strongest bond was achieved with the heat-cured resin Microlon, whereas Triad resin displayed the stronger bond between the two light-cured resins. Scanning electron microscopic analysis showed that the nature and location of the fracture sites was different among the three resins tested.