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Full coverage metal crowns with lingual ledge attached to it cast OT CAP unilateral attachment, and unilateral metal cast partial denture
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BACKGROUND: Utilization of attachments in a removable partial denture is highly essential not only as a line of treatment but also as it has a remarkable impact on the denture’s durability during the function. The attachment should act as a stress breaking system preserving the abutment teeth.
AIM: This consideration aimed to verify the convention...
Citations
... 16 This polymer presents low weight, excellent shock absorption properties and a Young's modulus (Y) close to that of the cortical bone, 17 allowing for the reduction of stress on the abutment and providing enhanced protection for a more uniform distribution of masticatory forces. 13,[18][19][20] The cortical bone around the dental implants experiences more stress than do other regions. 21,22 In a FEA study assessing different framework materials, the carbon fiber-reinforced polyether ether ketone (CFR-PEEK) framework reduced cortical bone stress distribution around the implants in all designs of mandibular completearch implant restorations when compared with PEEK, 17 exhibiting a higher Young's modulus (Y) and improved stress distribution on both the implant and surrounding tissues compared to PEEK. ...
... However, CFR-PEEK presents a Y value close to that of the mandibular bone, allowing for reduction of stress transfer to the abutment, and increasing protection because of more evenly distributed masticatory forces. 13,[18][19][20] Although CFR-PEEK and CoCr presented different Y values under the simulated clinical conditions, both materials showed a similar biomechanical behavior. ...
This study aimed to assess the biomechanical behavior of reinforcement materials [cobalt chromium alloy (CoCr) and carbon fiber-reinforced polyether ether ketone (CFR-PEEK)] and their extensions (short: 15 mm and long: 25 mm) of single implant-retained mandibular overdentures (MO-1) by 3D finite element analysis (FEA), comparing them with MO-1 without a framework. Five models (CoCr-Short, CFR-PEEK-Short, CoCr-Long, CFR-PEEK-Long, and no framework) were created using the McNeel Rhinoceros 3D software, version 7.0. Stress distribution analysis by FEA was performed using the Optstruct solver, and a 30° oblique load (100 N) was applied in the anterior region (50 N on each central incisor). Biomechanical behavior was analyzed by overdenture displacement, maximum (MaxP) and minimum principal (MinP) stress, and von Mises stress. The MO-1 model ‘without a framework’ produced the largest dislocation, MinP stress on the mucosa, and MaxP stress in the cortical bone. Regardless of the extension of the framework, CFR-PEEK had minor MinP stress in the mucosa and lower overdenture displacement. The ‘CoCr-Long’ and ‘CFR-PEEK-Long’ models had higher von Mises stress on the implant housing, and MaxP stress on the O’ring nylon conventional implant and overdenture. The ‘CoCr-Short’ and ‘ CFR-PEEK-Short’ models showed a greater tendency for tension concentration solely in the framework. The incorporation of a framework into MO-1 decreased stress concentration on the overdenture, resulting in lower stress on the attachment, mucosa, implant, and peri-implant bone, irrespective of the material used. The short framework, however, performed better biomechanically in MO-1, and it is therefore the most recommended option. CFR-PEEK showed favorable biomechanical outcomes, and is suggested for reinforcement of MO-1.
... Such an alloy has revealed good clinical results due to its high modulus of elasticity, hardness and low cost [9]. Thanks to the wide applications of the digital technology in the dental field, esthetic materials as Zirconia and Polyetheretherketone (PEEK) can be used nowadays for fabrication of different prosthesis with high precision and passive seating [10][11][12]. Zirconia was used for fabrication of bridges, double crowns and extracoronal attachments due to its biocompatibility, good esthetics, high hardness, durability and wear resistance [9,[13][14][15]. High-strength polymeric resins as the PEEK material have been introduced as a promising alternative to ceramic materials [10]. ...
... Stress analysis studies were used for evaluation of the stress patterns induced by Co-Cr, Zirconia and PEEK materials in RPD. Sadek et al. concluded that PEEK could be a material of choice for restoring free end partially edentulous cases due to its superior biological and mechanical properties [12]. Furthermore, Saleh et al. used strain gauge analysis to compare the stresses induced by different Co-Cr attachment designs [7]. ...
... Esthetic core materials as Zirconia and PEEK have been used for the fabrication of dental attachments in prosthodontics [12,14,15]. However, the stresses induced by them when used as an extracoronal attachment in distal extension removable partial denture were not compared and mentioned in the literature. ...
Background
Preservation of the remaining structures while maintaining an esthetic appearance is a major objective in removable partial prosthodontics. So, the aim of the current study was to compare the stresses induced on the supporting structures by two digitally produced esthetic core materials; Zirconia and Polyetheretherketone when used as an extracoronal attachment in distal extension removable partial dentures using strain gauge analysis.
Methods
A mandibular Kennedy class II stone cast with the necessary abutments’ preparations was scanned. The mandibular left canine and first premolar teeth were virtually removed. An acrylic mandibular left canine and first premolar teeth were prepared with heavy chamfer finish line and scanned. Virtual superimposition of the acrylic teeth in their corresponding positions was done. Two strain gauge slots were designed: distal to the terminal abutment and in the residual ridge. Two models and two sets of scanned teeth were digitally printed. The printed teeth were then placed in their corresponding sockets in each model and scanned. The attachment design was selected from the software library and milled out of Zirconia in the model ZR and Polyetheretherketone in the model PE. Five removable partial dentures were constructed for each model. The strain gauges were installed in their grooves. A Universal testing machine was used for unilateral load application of 100 N (N). For each removable partial denture, five measurements were made. The data followed normal distribution and were statistically analyzed by using unpaired t test. P value < 0.05 was considered to be statistically significant.
Results
During unilateral loading unpaired t test showed statistically significant difference (p = 0.0001) in the microstrain values recorded distal to the abutment between the models ZR (-1001.6 µε ± 24.56) and PE (-682.6 µε ± 22.18). However, non statistically significant difference (p = 0.3122) was observed in the residual ridge between them; ZR (16.2 µε ± 4.53) and PE (15 µε ± 3.74).
Conclusions
In removable partial dentures, Polyetheretherketone extracoronal attachment induces less stress on the supporting abutments compared to the zirconia one with no difference in the stresses induced by them on the residual ridge.
... Strain on the abutments were evaluated across four treatment groups each using different implant designs. The PEEK-PEEK treatment demonstrated a more desirable stress distribution than other materials [149]. PEEK has also been used for dental implant abutments and an in vivo study evaluated biofilm formation in titanium, zirconia, and PEEK implant abutments. ...
... Removable partial dentures can be fabricated with the integration of the clasp, denture base, framework, and artificial teeth. Some scholars have discovered that the integrated cutting of PEEK material could circumvent issues of stress concentration and the propensity for easy fractures at the joints between different materials observed in traditional cast dentures [4,14]. For patients with anterior tooth isolated loss, artificial teeth often break off repeatedly due to the large bite force of the patient's anterior teeth, which brings many troubles to the patient. ...
... Suitability is considered a role criterion for evaluating the clinical feasibility of the RPD framework [16]. There are primarily two manufacturing methods for PEEK removable partial dentures: one is directly milling the PEEK billet, and the other is using resin printing combined with the lost wax technique and filled with PEEK [4,16]. The research demonstrated that the removable partial dentures obtained by direct manufacturing technology achieved better accuracy than the removable partial dentures manufactured by indirect manufacturing technology. ...
... With technological advancements, the requirements of removable partial dentures are not only limited to the restoration of function but also focus on beauty and comfort [3]. Nonetheless, the problem of significant differences in the resistance properties between plastics and metals, along with stress concentration at the joint, cannot be ignored [4]. ...
The object of the study was to evaluate the suitability and trueness of the removable partial denture (RPD) framework fabricated by polyether ether ketone (PEEK) with the CAD-CAM technology in vitro. Four different types of dentition defects were selected. In each type, five PEEK RPD frameworks were fabricated by the CAD-CAM technology, while five Co-Cr RPD frameworks were made by traditional casting. The suitability of the framework was evaluated by silicone rubber film slice measurement and the three-dimensional image overlay method. The trueness of the PEEK framework was detected by the three-dimensional image overlay method. Data were statistically analyzed with the use of an independent samples t-test (α = 0.05). The suitability values by silicone rubber film slice measurement of the PEEK group were lower than those of the Co-Cr group in four types, with the differences indicating statistical significance (p < 0.05) in type one, type two, and type four. The suitability values using the three-dimensional image overlay method showed no statistical differences (p > 0.05) between the two groups in four types. The trueness values of the PEEK group were within the allowable range of clinical error. The suitability and trueness of the PEEK RPD framework fabricated by CAD-CAM technology met the requirements of the clinical prosthesis.
... [37,38] . Multiple researches have explored stress analysis concerning extra coronal attachments through the utilization of strain gauges investigating unilateral, bilateral, or both types of stresses [39][40][41][42] . ...
... Numerous studies have examined how the material and design variations of extra-coronal attachments impact the strain produced and transmitted by removable partial dentures to the abutment teeth and the edentulous ridge. [10][11][12][13]24,39,40] . It has been reported that attachment retained RPDs with zirconia and metal resin bonded attachments generate significantly lower strain values compared to those with extra coronal attachments involving full veneer retainers rendering them a more favorable option for distal extension removable partial dentures [24] . ...
... It has been reported that attachment retained RPDs with zirconia and metal resin bonded attachments generate significantly lower strain values compared to those with extra coronal attachments involving full veneer retainers rendering them a more favorable option for distal extension removable partial dentures [24] . Furthermore, the use of polyetheretherketone (PEEK) as a material for partial denture attachment and framework has been found to decrease induced strain around abutment teeth and edentulous residual ridge [40] . ...
... Studies support the use of PEEK as researchers have found that it expressed the most favorable stress distribution compared with other treatments and especially around abutments. 5 Also, the clinical use of PEEK varies from an alternative to polymethylmethacrylate (PMMA), computer-aided design/ computer-aided manufacturing (CAD-CAM) restorations, dental implants, and metal braces and hooks. 6,7 Zoidis et al. created a modified PEEK material, known as biohigh performance polymer, that is a biocompatible, nonallergic, and rigid material that can form an alternative for the fabrication of distal extension removable dental prosthesis frameworks. ...
... T and D are studied as a pair because both are stop consonants in which the tongue stops the flow of air at the front of the oral cavity the main difference is in the amount of air expelled which is more in D than T. (15) (S,T,D, N,L) theses sounds depends on the thickness of the denture, the anteroposterior position of teeth, vertical dimension of occlusion and the width of the dental arch in addition to the relation between upper and lower anterior teeth for the (S)sound. (20) In both groups (Co-Cr and PEEK) the mean duration of sound production at the time of denture insertion was longer compared to the duration at one month of insertion while no significant change occurred after 3 months. Speech is greatly affected by the inclination of maxillary anterior teeth as well as the thickness of the anterior palatal surface of the denture. ...
... This was proven in the follow up visits in which there was obvious improvement in denture accommodation manifested by the shorter mean duration of sound production. (16,20) PEEK group showed overall higher mean duration of sound production compared to the Co-Cr group this could be attributed to the difference in the inherited material properties that required thicker components to compensate for the difference in the material hardness and so this was reflected on the sound duration. Moreover, the thickness of the PEEK in the palatal area led to the early tongue contact which also might explain the higher duration of sound production in case of the PEEK group. ...
... Many studies were conducted on stress analysis for extra-coronal attachments using strain gauges. They examined the stresses unilateral, bilateral or both [39][40][41][42]. ...
Background: The strain developed by different extra-coronal attachment materials during loading in aqueous environment as well as the effect of denture insertion and removal cycles is of prime importance. Accordingly, the aim of the current study was to assess the induced strain of different extra-coronal attachment materials in mandibular Kennedy class I metallic removable partial dentures after one year of clinical simulation.
Methods: Twelve identical 3D-printed models representing mandibular Kennedy class I with first premolars as principal abutments bilaterally were fabricated having 4 removable dies each; canine and first premolar on which two splinted crowns with three different extra-coronal attachment materials (group A: PEEK/BioHPP, group B: zirconia, group C: metal)were fabricated bilaterally. Each of the 3D-printed models (n=4 for each group) was designed with four strain gauge slots, two on each side: 1mm distal to the first premolar (SG1 &SG3) and 1 cm away from the first one at the edentulous ridge (SG2&SG4). Removable partial dentures were constructed, and strain gauges were used to measure the strain applied both unilaterally and bilaterally by a universal testing machine before and after one year of clinical simulation where, an average of 5 readings were recorded for each model. Clinical simulation was performed through chewing simulator and dentures insertion/removal cycles. Repeated measures ANOVA and Tukey’s post-hoc test were used for data analysis at p < 0.05.
Results: PEEK (BioHPP) group revealed the lowest induced strain before and after one year of clinical simulation compared to zirconia and metal groups during both unilateral and bilateral loading with significantly higher induced strain at SG2 & SG4 compared to that induced at SG1 & SG3. Metal group showed the same pattern but with significantly higher values compared to PEEK (BioHPP). For zirconia group after one year of clinical simulation, bilateral loading revealed significant decrease in induced strain at SG1&SG3 with a significant increase at SG2 &SG4.
Conclusions: PEEK (BioHPP) is more effective in stress dissipation as an extra-coronal attachment in removable partial dentures compared to zirconia and metal. After one year of clinical simulation.
... Extra coronal attachments as direct retainers that extend from the full coverage crown of abutments can provide a rigid, movable, or resilient connection between abutments and RPD [8][9][10][11][12][13][14]. Proper materials selection of RPDs' framework fabrication affects stresses transmitted to the supportive structures [11]. ...
... Attachment retained RPD is the treatment modality that can facilitate both an aesthetic and functional replacement of missing teeth and oral structures [12]. Elimination of labial or buccal clasp arms increases the patient's psychological acceptance of the denture [8][9][10][11][12][13]. Mechanical behaviour of variable materials in the dental field can be measured with different techniques including photoelasticity measurement, strain gauge-based measurements, optic measurement, and computational finite analysis [15,23]. ...
... A strain gauge is a tool designed to measure the strain of an entity [3,4,8,10]. Strain gauge evaluation is a method for measuring micro-strains, by measuring electrical resistance [8,13,24]. ...
Objective: This study aims to compare the strain induced in the supporting structures of unilateral mandibular removable partial denture frameworks retained by extra-coronal attachments fabricated with three different materials. Material and Methods: Three mandibular class II digitally designed and printed acrylic models with detachable abutments were used to fabricate three removable partial denture framework with extra coronal attachments from three different materials. A total of 33 models were prepared for strain testing (n=11). Models were divided into three groups according to framework’s material: porcelain fused to cobalt chromium (PFM), polyetherketoneketone (PEKK) and polyetheretherketone (PEEK) group. Unilateral load of 60 N was applied in the three groups and strains were measured around the main abutment and saddle area using strain gauge. Results: Statistical analysis was performed using Shapiro-Wilk’s test and by checking data distribution. Data were found to be non-parametric and were analysed using Kruskal-Wallis test followed by Dunn’s post hoc test with Bonferroni correction. PFM group showed significantly the highest strain values around abutment, slot 1 (1mm distal to the socket of the last abutment) and slot 2 (1 cm away from slot 1) respectively (843.00±23.08, 91.00±6.52 and 1274.00±65.71) than the other tested groups (p<0.05) at same tested sites respectively followed by PEKK group (384.00±37.48, 81.00±2.24 and 135.00±0.00) and PEEK group (29.00±4.18, 63.00±4.47 and 52.00±5.70). Conclusions: PEEK and PEKK for partial denture framework with extra coronal attachments are adequate alternative to PFM due to their good mechanical response applying less strain on supportive structures in free-end cases. PEEK induces lower strain magnitude on the supporting structures when compared to PEKK. KEYWORDS Denture precision attachment; Dental stress analysis; Partial denture; Polyetheretherketone; Removable partial denture.
... However, PEEK is characterized by being bio-inert and has a low surface energy, which causes difficulties for its potential applications in dentistry specifically in adhesiveness and implant osseointegration. Moreover, PEEK looks opaque and greyish in appearance, and thus aesthetic materials such as veneering or resin composites are used to cover [22][23][24][25][26][27] . Retention of this attachment depend mainly on friction between the attachment's inner surface and the ball abutment. ...
