1
|
Rohym SM, Badra H, Nassar H. Comparative evaluation of marginal adaptation and fatigue resistance of endodontically treated premolars restored with direct and indirect coronal restorations: an in vitro study. BMC Oral Health 2024; 24:696. [PMID: 38879492 PMCID: PMC11179332 DOI: 10.1186/s12903-024-04382-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2024] [Accepted: 05/17/2024] [Indexed: 06/19/2024] Open
Abstract
BACKGROUND An optimum restoration for reconstructing endodontically treated teeth should provide excellent marginal adaptation, high fracture resistance as well as maximum tooth structure conservation. The purpose of this study was to evaluate the marginal adaptation and fatigue resistance of different coronal restorations in endodontically treated premolars. METHODS Thirty sound maxillary first premolars were endodontically treated and received MOD cavities. Teeth were randomly allocated into three groups (n = 10) according to the type of coronal restoration: Group R: polyethylene fibers (ribbond), fibers-reinforced composite (everX posterior) and final layer of nano-hybrid composite. Group O: indirect lithium disilicate overlay and Group C: fiber-post, resin composite restoration, and lithium disilicate crown. Marginal gap assessment was performed before and after thermocycling (5000 cycles) using stereomicroscope. Samples were subjected to stepwise-stress loading starting at 200 N, and increased by 100 N in each step until failure occurred. Statistical analysis was done by One-way ANOVA followed Tukey`s Post Hoc test for multiple comparison. Paired t test was used to compare the marginal adaptation before and after thermocycling. Survival probability was evaluated by Life table survival analysis. Failure mode analysis was performed with Chi-square test. RESULTS Marginal gap was significantly the lowest in group R (37.49 ± 5.05) and (42.68 ± 2.38), while being the highest in group C (59.78 ± 5.67) and (71.52 ± 5.18) in before and after thermocycling respectively (P < 0.0001). Fatigue resistance was the highest for group O (1310.8 ± 196.7), and the lowest for group R (905.4 ± 170.51) with a significant difference between groups (P < 0.0001). Crown group had the highest percentage (80%) of catastrophic failure, while, overlay group exhibited the lowest (20%). CONCLUSIONS Direct restoration without cuspal coverage using ribbon fibers with short FRC provided better marginal adaptation than indirect overlays and crowns, but fatigue resistance wasn't significantly improved. Adhesive ceramic overlays showed the best fatigue performance and the least catastrophic failure rate compared to both direct fiber-reinforced composite and indirect ceramic full coverage restorations. CLINICAL SIGNIFICANCE Indirect adhesive overlays are a suitable, more conservative restorative option for endodontically treated teeth than full coverage restorations, especially when tooth structure is severely compromised.
Collapse
Affiliation(s)
- Shaimaa Mohammed Rohym
- Conservative Dentistry Department, Faculty of Oral and Dental Medicine, Ahram Canadian University, 6th of October City, Egypt.
| | - Heba Badra
- Endodontic Department, Faculty of Oral and Dental Medicine, Ahram Canadian University, 6th of October City, Egypt
| | - Hanaa Nassar
- Fixed Prosthodontics Department, Faculty of Oral and Dental Medicine, Ahram Canadian University, 6th of October City, Egypt
| |
Collapse
|
2
|
Zeng B, Luo B, Hu J, Meng D, Zhang J, Cao X, Jiang Q. Effect of margin designs and loading conditions on the stress distribution of endocrowns: a finite element analysis. BMC Oral Health 2024; 24:657. [PMID: 38840138 PMCID: PMC11151608 DOI: 10.1186/s12903-024-04422-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2024] [Accepted: 05/30/2024] [Indexed: 06/07/2024] Open
Abstract
BACKGROUND Margin designs and loading conditions can impact the mechanical characteristics and survival of endocrowns. Analyzing the stress distribution of endocrowns with various margin designs and loading conditions can provide evidence for their clinical application. METHODS Three finite element analysis models were established based on the margin designs: endocrown with a butt-joint type margin (E0), endocrown with a 90° shoulder (E90), and endocrown with a 135° shoulder (E135). The E0 group involved lowering the occlusal surface and preparing the pulp chamber. The E90 group created a 90° shoulder on the margin of model E0, measuring 1.5 mm high and 1 mm wide. The E135 group featured a 135° shoulder. The solids of the models were in fixed contact with each other, and the materials of tooth tissue and restoration were uniform, continuous, isotropic linear elasticity. Nine static loads were applied, with a total load of 225 N, and the maximum von Mises stresses and stress distribution were calculated for teeth and endocrowns with different margin designs. RESULTS Compared the stresses of different models under the same loading condition. In endocrowns, when the loading points were concentrated on the buccal side, the maximum von Mises stresses were E0 = E90 = E135, and when there was a lingual loading, they were E0 < E90 = E135. In enamel, the maximum von Mises stresses under all loading conditions were E0 > E90 > E135. In dentin, the maximum von Mises stresses of the three models were basically similar except for load2, load5 and load9. Compare the stresses of the same model under different loading conditions. In endocrowns, stresses were higher when lingual loading was present. In enamel and dentin, stresses were higher when loaded obliquely or unevenly. The stresses in the endocrowns were concentrated in the loading area. In enamel, stress concentration occurred at the cementoenamel junction. In particular, E90 and E135 also experienced stress concentration at the shoulder. In dentin, the stresses were mainly concentrated in the upper section of the tooth root. CONCLUSION Stress distribution is similar among the three margin designs of endocrowns, but the shoulder-type designs, especially the 135° shoulder, exhibit reduced stress concentration.
Collapse
Affiliation(s)
- Baijin Zeng
- Department of Prosthodontics, Beijing Stomatological Hospital, School of Stomatology, Capital Medical University, No. 4 Tiantanxili, Dongcheng District, Beijing, 100050, China
| | - Bin Luo
- Department of Prosthodontics, Beijing Stomatological Hospital, School of Stomatology, Capital Medical University, No. 4 Tiantanxili, Dongcheng District, Beijing, 100050, China
| | - Jiangqi Hu
- Department of Prosthodontics, Beijing Stomatological Hospital, School of Stomatology, Capital Medical University, No. 4 Tiantanxili, Dongcheng District, Beijing, 100050, China
| | - Dan Meng
- Department of Prosthodontics, Beijing Stomatological Hospital, School of Stomatology, Capital Medical University, No. 4 Tiantanxili, Dongcheng District, Beijing, 100050, China
| | - Jiebing Zhang
- Department of Prosthodontics, Beijing Stomatological Hospital, School of Stomatology, Capital Medical University, No. 4 Tiantanxili, Dongcheng District, Beijing, 100050, China
| | - Xu Cao
- Department of Prosthodontics, Beijing Stomatological Hospital, School of Stomatology, Capital Medical University, No. 4 Tiantanxili, Dongcheng District, Beijing, 100050, China.
| | - Qingsong Jiang
- Department of Prosthodontics, Beijing Stomatological Hospital, School of Stomatology, Capital Medical University, No. 4 Tiantanxili, Dongcheng District, Beijing, 100050, China.
| |
Collapse
|
3
|
Jurado CA, Lee D, Ramirez P, Cortes-Treviño DA, Tsujimoto A. Fracture Resistance of Chairside CAD/CAM Lithium Disilicate-reinforced Ceramic Occlusal Veneers With and Without Margin and Full Coverage Crowns. Oper Dent 2024; 49:84-90. [PMID: 38058016 DOI: 10.2341/23-043-l] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/31/2023] [Indexed: 12/08/2023]
Abstract
OBJECTIVE The aim of this investigation was to compare the fracture resistance of chairside computer-aided design and computer-aided manufacturing (CAD/CAM) lithium disilicate-reinforced ceramic occlusal veneers with and without margin and traditional full coverage premolar crowns. METHODS AND MATERIALS A total of 60 chairside CAD/CAM lithium disilicate-reinforced ceramic (Amber Mill, Hass Bio) restorations were designed and fabricated with a chairside CAD/CAM system (CEREC Dentsply Sirona). The restorations were divided into three groups (n=20): 1) occlusal veneer with 1.0-mm uniform occlusal thickness and with chamfer margin; 2) occlusal veneer with 1.0-mm uniform occlusal thickness and without margin; and 3) full coverage crown with uniform occlusal thickness and gingival margin. Occlusal veneers and crowns were cemented with dual cured resin luting cement (Multilink, Ivoclar Vivadent) to printed resin dies, load cycled (5 million load cycles at 1 Hz with 275 N force), and then loaded until fracture. Load at break (LB) and peak load (PL) until fracture were recorded. Scanning electron microscope images of the tested restorations on the abutments were obtained. RESULTS Fracture strengths were different depending on the design of the restoration. There was no significant difference in fracture strength between the two types of occlusal veneer (LB: 1132.45 N; PL: 1143.30 N for veneers with margin; LB: 1149.25 N; PL: 1219.05 N for veneers without margin). Full coverage crowns showed the lowest fracture resistance (LB: 936.26 N, PL: 976.42 N), which was significantly lower than both designs of occlusal veneer. CONCLUSIONS The fracture resistance of the CAD/CAM lithium disilicate-reinforced ceramic restorations was influenced by the design. Occlusal veneers with and without margin displayed higher fracture resistance than traditional crowns.
Collapse
Affiliation(s)
- C A Jurado
- Carlos Alberto Jurado, DDS, MS, clinical associate professor, University of Iowa College of Dentistry and Dental Clinics, Iowa City, IA, USA
| | - D Lee
- Damian Lee, DDS, MS, associate professor and chair, Department of Prosthodontics, Tufts University School of Dental Medicine, Boston, MA, USA
| | - P Ramirez
- Paulette Ramirez, BS, dental student, Texas Tech University Health Sciences Center El Paso, Woody L. Hunt School of Dental Medicine, El Paso, TX, USA
| | - D A Cortes-Treviño
- Daniel Alberto Cortes-Treviño, DDS, MS, private practice, Dallas, TX, USA
| | - A Tsujimoto
- *Akimasa Tsujimoto, DDS, PhD, professor and chair, Department of Operative Dentistry, Aichi Gakuin University School of Dentistry, Nagoya, Aichi, Japan; adjunct associate professor, Department of Operative Dentistry, University of Iowa College of Dentistry, Iowa City, Iowa, USA; visiting associate professor, Department of General Dentistry, Creighton University School of Dentistry, Omaha, NE, USA
| |
Collapse
|
4
|
Matic T, Zebic ML, Miletic V, Trajkovic I, Milosevic M, Racic A, Veljovic D. Hydroxyapatite-based dental inserts: Microstructure, mechanical properties, bonding efficiency and fracture resistance of molars with occlusal restorations. J Biomed Mater Res B Appl Biomater 2024; 112:e35331. [PMID: 37792306 DOI: 10.1002/jbm.b.35331] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2023] [Revised: 07/23/2023] [Accepted: 09/07/2023] [Indexed: 10/05/2023]
Abstract
This study aimed to (1) comparatively analyze properties of Sr- and Mg-substituted hydroxyapatite (HAP)-based dental inserts; (2) evaluate insert bonding to restorative materials, and (3) evaluate the effect of doped HAP inserts on fracture resistance (FR) of human molars with large occlusal restorations. By ion-doping with Sr or Mg, 3 insert types were obtained and characterized using XRD, SEM, Vickers hardness and fracture toughness. Shear bond strength (SBS) was determined between acid etched or unetched inserts and following materials: Maxcem cement (Kerr); Filtek Z250 (3M) bonded with Single Bond Universal (SBU; 3M) or Clearfil Universal (Cf; Kuraray). Modified Class I cavities were prepared in 16 intact molars and restored using insert + composite or composite only (control) (n = 8/group). FR of restored molars was determined by static load until fracture upon thermal cycling. Fracture toughness was similar between Sr/Mg-doped inserts (0.94-1.04 MPam-1/2 p = .429). Mg-doped inserts showed greater hardness (range 4.78-5.15 GPa) than Sr6 inserts (3.74 ± 0.31 GPa; p < .05). SBS for SBU and Cf adhesives (range 7.19-15.93 MPa) was higher than for Maxcem (range 3.07-5.95 MPa) (p < .05). There was no significant difference in FR between molars restored with insert-containing and control restorations (3.00 ± 0.30 kN and 3.22 ± 0.42 kN, respectively; p > .05). HAP-based inserts doped with Mg/Sr had different composition and mechanical properties. Adhesive bonding to inserts resulted in greater bond strength than cementation, which may be improved by insert acid-etching. Ion-doped HAP inserts did not affect FR of restored molars. In conclusion, HAP-based dental inserts may potentially replace dentin in large cavities, without affecting fracture resistance of restored teeth.
Collapse
Affiliation(s)
- Tamara Matic
- Innovation Center of the Faculty of Technology and Metallurgy, Ltd, Belgrade, Serbia
| | | | - Vesna Miletic
- Faculty of Medicine and Health, Sydney Dental School, The University of Sydney, Surry Hills, New South Wales, Australia
| | - Isaak Trajkovic
- Innovation Center of the Faculty of Mechanical Engineering, Ltd, Belgrade, Serbia
| | - Milos Milosevic
- Innovation Center of the Faculty of Mechanical Engineering, Ltd, Belgrade, Serbia
| | - Aleksandar Racic
- School of Dental Medicine, University of Belgrade, Belgrade, Serbia
| | - Djordje Veljovic
- Faculty of Technology and Metallurgy, University of Belgrade, Belgrade, Serbia
| |
Collapse
|
5
|
Pilecco RO, da Rosa LS, Pereira GKR, Tribst JPM, May LG, Valandro LF. The loss of resin cement adhesion to ceramic influences the fatigue behavior of bonded lithium disilicate restorations. J Mech Behav Biomed Mater 2023; 148:106169. [PMID: 37837872 DOI: 10.1016/j.jmbbm.2023.106169] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2023] [Revised: 10/06/2023] [Accepted: 10/06/2023] [Indexed: 10/16/2023]
Abstract
When partial and/or non-retentive preparation, such as those for occlusal veneers, is indicated, a proper and stable adhesion is essential. Therefore, the aim of this in vitro study was to evaluate the effect of loss of adhesion in different regions of the bonding interface on the fatigue behavior of simplified lithium disilicate restorations. For this, lithium disilicate (IPS e.max CAD) discs (1 mm thick and Ø = 10 mm) were fabricated, polished with #400-, #600-, #1200-grit silicon carbide (SiC) papers, and crystallized. As substrate, fiber-reinforced resin epoxy discs (2.5 mm thick and Ø = 10 mm) were fabricated and polished with #600-grit SiC paper. The ceramic bonding surface was treated with 5% hydrofluoric acid and a silane-containing primer (Monobond N), while the substrate was etched with 10% hydrofluoric acid followed by the application of the bonding system primers (Primer A + B). A lacquer (nail polish) was used to simulate the loss of adhesion in specific areas according to the study design to compose the testing groups: bonded (control; did not received nail polish application); - non-bonded (loss of adhesion in the whole specimen area); - margin (loss of adhesion in the ceramic margin); - center (loss of adhesion in the ceramic central area). The adhesive area of partially bonded groups was 50% of the adhesive surface. Then, the discs (n = 12) were bonded to the respective substrate using a resin cement (Multilink N), light-cured, water-stored for 90 days, and subjected to thermocycling (25,000 cycles, 5° to 55 °C) before testing. A cyclic fatigue test was run (20 Hz, initial load of 200 N for 5000 cycles, 50 N step size for 10,000 cycles each until specimen failure), and the fatigue failure load and number of cycles for failure were recorded. As complementary analysis, finite element analysis (FEA) and scanning electron microscopy analysis were performed. Kaplan-Meier log-rank (Mantel-Cox) was conducted for survival analysis. The results showed that as the loss of adhesion reaches the central area, the worse is the fatigue behavior and the higher is the stress peak concentration in the ceramic bonding surface. The bonded specimens presented better fatigue behavior and stress distribution compared to the others. In conclusion in a non-retentive preparation situation, proper adhesion is a must for the restoration fatigue behavior even after aging; while the loss of adhesion reaches central areas the mechanical functioning is compromised.
Collapse
Affiliation(s)
- Rafaela Oliveira Pilecco
- Post-Graduate Program in Oral Sciences, Center for Development of Advanced Materials, Division of Prosthodontics-Biomaterials, Federal University of Santa Maria (UFSM), Santa Maria, Brazil.
| | - Lucas Saldanha da Rosa
- Post-Graduate Program in Oral Sciences, Center for Development of Advanced Materials, Division of Prosthodontics-Biomaterials, Federal University of Santa Maria (UFSM), Santa Maria, Brazil.
| | - Gabriel Kalil Rocha Pereira
- Post-Graduate Program in Oral Sciences, Center for Development of Advanced Materials, Division of Prosthodontics-Biomaterials, Federal University of Santa Maria (UFSM), Santa Maria, Brazil.
| | - João Paulo Mendes Tribst
- Department of Reconstructive Oral Care, Academic Centre for Dentistry Amsterdam (ACTA), University of Amsterdam, the Netherlands.
| | - Liliana Gressler May
- Post-Graduate Program in Oral Sciences, Center for Development of Advanced Materials, Division of Prosthodontics-Biomaterials, Federal University of Santa Maria (UFSM), Santa Maria, Brazil.
| | - Luiz Felipe Valandro
- Post-Graduate Program in Oral Sciences, Center for Development of Advanced Materials, Division of Prosthodontics-Biomaterials, Federal University of Santa Maria (UFSM), Santa Maria, Brazil.
| |
Collapse
|
6
|
Zahran M, Abo El-Farag S, Soltan H, Attia A. Fracture load of ultrathin occlusal veneers: Effect of thickness and surface conditioning. J Mech Behav Biomed Mater 2023; 145:106030. [PMID: 37473575 DOI: 10.1016/j.jmbbm.2023.106030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Revised: 07/12/2023] [Accepted: 07/15/2023] [Indexed: 07/22/2023]
Abstract
OBJECTIVE This in-vitro study is planned to analyze the effect of different thicknesses of ceramic occlusal veneers and different surface treatments on fracture resistance. MATERIALS AND METHODS A total of 48 sound mandibular molars are anatomically prepared from the occlusal surface with two different thicknesses (1.0 and 0.5 mm). CAD/CAM zirconia-reinforced glass ceramic blocks (Vita Suprinity) are used for fabricating occlusal veneers. The teeth are randomly divided into two primary groups A and B (n=24) according to occlusal veneer thickness. Each group is subdivided according to surface conditioning into three equal subgroups (n=8)-subgroup HF: etching with hydrofluoric acid and ceramic primer application; subgroup APF: etching with acidulated phosphate fluoride and ceramic primer application; subgroup EP: conditioning with etch and prime only. Dual-cure adhesive resin cement (Multilink Automix) is utilized to adhesively bond the veneers. All specimens are subjected to 240,000 cycles of dynamic load aging prior to the fracture resistance test. The fracture resistance is measured in Newton (N). The Failure mode patterns are analyzed and categorized using a scanning electron microscope (SEM). The results are analyzed using a two-way ANOVA with Bonferroni's Post-Hoc test, followed by a one-way ANOVA for each factor. That is in addition to one-way ANOVA for surface treatment under each thickness, each followed by Bonferroni's Post-Hoc test. Then, a T-test is used to compare the two thicknesses under each surface treatment. All tests are set at 0.05 significance level. RESULTS The two-way ANOVA test revealed that restoration thickness and surface treatment both significantly affect the fracture resistance values (p<0.05). The highest fracture resistance mean (2672±216N) is obtained from HF at 1.0 mm thickness, while the lowest mean (2104±299N) is obtained from APF at 0.5 mm thickness. CONCLUSION All test groups, regardless of thickness, demonstrated fracture resistance values that exceeded both normal and parafunctional bite forces. The veneers that bonded after hydrofluoric acid etching followed by ceramic primer application showed more favourable fracture patterns.
Collapse
Affiliation(s)
- Maged Zahran
- Department of Fixed Prosthodontics, Faculty of Dentistry, Mansoura University, Mansoura 35516, Egypt.
| | - Shaimaa Abo El-Farag
- Department of Fixed Prosthodontics, Faculty of Dentistry, Mansoura University, Mansoura 35516, Egypt.
| | - Hassan Soltan
- Production and Mechanical Design Engineering Department, Faculty of Engineering, Mansoura University, Mansoura 35516, Egypt.
| | - Ahmed Attia
- Department of Fixed Prosthodontics, Faculty of Dentistry, Mansoura University, Mansoura 35516, Egypt.
| |
Collapse
|
7
|
Wang M, Hong Y, Hou X, Pu Y. Management and prognosis of a vital cracked tooth by occlusal veneer for 14 months: A case report. Clin Case Rep 2023; 11:e7714. [PMID: 37564609 PMCID: PMC10410118 DOI: 10.1002/ccr3.7714] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Revised: 07/06/2023] [Accepted: 07/08/2023] [Indexed: 08/12/2023] Open
Abstract
Key Clinical Message An occlusal veneer is an ultrathin restoration method and a minimally invasive approach that can preserve more dental tissue and provide better aesthetic outcomes, thus increasing patient satisfaction. Abstract An occlusal veneer is an ultrathin restoration method and a minimally invasive approach that can preserve more dental tissue and provide better aesthetic outcomes, thus increasing patient satisfaction; however, no previous studies reported on treating cracked teeth using occlusal veneer. Accordingly, we described the diagnosis and treatment process of a cracked tooth using occlusal veneer in a single case. A 29-year-old male presented at our dental clinic complaining of biting pain in the mandibular molar on the right-hand side. A routine oral examination with radiography was performed to evaluate the oral condition and treatment planning. The #16 tooth had a crack line surrounding the whole distal-lingual cusp from the occlusal surface. After discussing various therapeutic options with the patient, an occlusal veneer was performed. One week after treatment with occlusal veneer, the patient had no complaints. A 14-month follow-up showed promising clinical and radiographic outcomes. Occlusal veneer is an alternative treatment option for a cracked tooth, as it can preserve more dental tissue and potentially save pulp vitality.
Collapse
Affiliation(s)
- Mengke Wang
- Second Clinical DivisionPeking University School and Hospital of Stomatology and National Center for Stomatology and National Clinical Research Center for Oral Diseases and National Engineering Research Center of Oral Biomaterials and Digital Medical DevicesBeijingPeople's Republic of China
| | - Yingying Hong
- First Clinical DivisionPeking University School and Hospital of Stomatology and National Center for Stomatology and National Clinical Research Center for Oral Diseases and National Engineering Research Center of Oral Biomaterials and Digital Medical DevicesBeijingPeople's Republic of China
| | - Xiaomei Hou
- Second Clinical DivisionPeking University School and Hospital of Stomatology and National Center for Stomatology and National Clinical Research Center for Oral Diseases and National Engineering Research Center of Oral Biomaterials and Digital Medical DevicesBeijingPeople's Republic of China
| | - Yinfei Pu
- Department of Oral EmergencyPeking University School and Hospital of Stomatology and National Center for Stomatology and National Clinical Research Center for Oral Diseases and National Engineering Research Center of Oral Biomaterials and Digital Medical DevicesBeijingPeople's Republic of China
| |
Collapse
|
8
|
Martins WF, Coelho CSS, Amaral FLBD, França FMG, Turssi CP, Cavalli V, Basting RT. Fracture load and failure mode of semi-direct resin composite occlusal veneers: Influence of design and mechanical cycling. J Mech Behav Biomed Mater 2023; 144:105961. [PMID: 37320893 DOI: 10.1016/j.jmbbm.2023.105961] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Revised: 06/05/2023] [Accepted: 06/06/2023] [Indexed: 06/17/2023]
Abstract
AIMS To evaluate the influence of the type of preparation and mechanical cycling on the fracture load and failure mode of semi-direct posterior resin composite restorations. METHODS In total, 70 healthy third molars were used; 10 belonging to the control group (C - unprepared teeth) and 60 teeth prepared and restored with nanoparticle resin composite, divided into 3 groups (n = 20): O - exclusively occlusal preparation (Table Top); OV - occlusal preparation with buccal extension (Veneerlay); OVP - Occlusal preparation with chamfer on the proximal and buccal-lingual/palatal surfaces (Overlay). The preparations were performed with diamond burs with a thickness of 1 mm. The restorations were made with nanoparticulate resin composite (Filtek Z350 XT) and subsequently received additional polymerization (thermoprocessing). Cementation was performed with the use of universal adhesive system (Single Bond Universal) on dental substrate and dual resin cement (RelyX ARC). Half of the teeth in each group (n = 10) were submitted to mechanical cycling, simulating 6 months of clinical service (5 × 105 fatigue cycles), under dynamic loading of 130 N, at a frequency of 2Hz. Fracture load tests were performed in a universal testing machine with a 200 kgf load cell. Failure mode was classified using scores. Generalized linear models and Fisher Exact tests were applied to the data (significance level of 5%). RESULTS There were no significant differences between the types of preparation (p = 0.9435), or relative to cycling (p = 0.3764). The Fisher Exact Test showed a significant association between the groups and the type of failure (p = 0.0006), with preparations O (with cycling) and OVP (with and without cycling) exhibiting most failures with restoration fractures without involvement of the dental remnant. CONCLUSIONS Semi-direct restorations showed resistance to fracture load similar to that of healthy teeth and were capable of withstanding functional masticatory loads. The type of preparation influenced the failure mode of teeth. The Table Top and Overlay types of preparations were those had fewer catastrophic failures, suggesting that since they are more conservative preparations, they made it possible for the tooth to receive a new restorative procedure in the future in cases of failures.
Collapse
Affiliation(s)
- Wellington Ferreira Martins
- Faculdade São Leopoldo Mandic, Rua José Rocha Junqueira 13, Bairro Swift, Campinas, CEP: 13045-755, São Paulo, Brazil.
| | - Camila Siqueira Silva Coelho
- Piracicaba Dental School, University of Campinas, 901 Limeira Avenue, Areião, 13414-903, Piracicaba, São Paulo, Brazil.
| | | | | | - Cecilia Pedroso Turssi
- Faculdade São Leopoldo Mandic, Rua José Rocha Junqueira 13, Bairro Swift, Campinas, CEP: 13045-755, São Paulo, Brazil.
| | - Vanessa Cavalli
- Piracicaba Dental School, University of Campinas, 901 Limeira Avenue, Areião, 13414-903, Piracicaba, São Paulo, Brazil.
| | - Roberta Tarkany Basting
- Faculdade São Leopoldo Mandic, Rua José Rocha Junqueira 13, Bairro Swift, Campinas, CEP: 13045-755, São Paulo, Brazil.
| |
Collapse
|
9
|
Alghauli M, Alqutaibi AY, Wille S, Kern M. Clinical outcomes and influence of material parameters on the behavior and survival rate of thin and ultrathin occlusal veneers: A systematic review. J Prosthodont Res 2023; 67:45-54. [PMID: 35545532 DOI: 10.2186/jpr.jpr_d_21_00270] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
PURPOSE Various oral rehabilitation approaches are available for severely worn dentition. However, evidence-based guidelines for permanent treatment are limited. This review aims to investigate clinical observational findings and compare in-vitro outcomes of thin and ultrathin occlusal veneers using different materials and approaches. METHODS An electronic search of online databases, such as PubMed (MEDLINE), BioMed Central (BMC), Cochrane, and Scopus, was performed for the 2009 - Jun 2021 period, following the PRISMA 2020 criteria. The reports sought for retrieval were all the articles evaluating the clinical outcomes of permanent full-mouth rehabilitation, and all in-vitro records that investigated and compared fracture strength, survival rate, and modes of failure of ultrathin (0.3 - 0.6 mm), thin (0.5 - 0.8 mm), and thick (0.8-1.5 mm) occlusal veneer restorations, with regard to the available indirect restorative materials. The Newcastle Ottawa risk of bias criteria was used to judge the clinical studies and a modified consort statement was used for the evaluation of in-vitro studies. The data of the included studies were extracted and grouped based on the similarity of the outcomes and study protocols. Data heterogeneity determined the qualitative and quantitative grouping of the results. RESULTS Two clinical and 17 in-vitro studies were included. Data exhibited heterogeneity within the materials, variables, testing protocols and observation periods. Therefore, only qualitative synthesis of the results was feasible. Clinically used 1 mm lithium disilicate overlays and ultrathin one-step no-prep polymer infiltrated ceramic network (PICN) occlusal veneers exhibited very high success and survival rates. The analysis of in-vitro studies exhibited variable survival rates and fracture load values, based on materials, thickness, and restorative approaches used. CONCLUSIONS Within the limitations of this systematic review, it can be concluded that the clinical outcomes of thin and ultrathin occlusal veneers/overlays are auspicious. In-vitro experimental results support the usage of the thin and ultrathin occlusal veneers.
Collapse
Affiliation(s)
- Mohamed Alghauli
- Department of Prosthodontics, Faculty of Dentistry, Ibb University, Ibb, Yemen.,Department of Prosthodontic, Propaedeutic and Dental Materials, Faculty of Dentistry, Kiel University, Kiel, Germany
| | - Ahmed Yaseen Alqutaibi
- Department of Prosthodontics, Faculty of Dentistry, Ibb University, Ibb, Yemen.,Substitutive Dental Science Department, College of Dentistry, Taibah University, Al-Madinah, Saudi Arabia
| | - Sebastian Wille
- Department of Prosthodontic, Propaedeutic and Dental Materials, Faculty of Dentistry, Kiel University, Kiel, Germany
| | - Matthias Kern
- Department of Prosthodontic, Propaedeutic and Dental Materials, Faculty of Dentistry, Kiel University, Kiel, Germany
| |
Collapse
|
10
|
Luo B, Sun X, He L, Zhao L, Liu X, Jiang Q. Impact of different axial wall designs on the fracture strength and stress distribution of ceramic restorations in mandibular first molar. BMC Oral Health 2022; 22:549. [PMID: 36456942 PMCID: PMC9714140 DOI: 10.1186/s12903-022-02577-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2022] [Accepted: 11/08/2022] [Indexed: 12/03/2022] Open
Abstract
BACKGROUND The purpose of this study was to investigate the fracture strength and stress distribution of four ceramic restorations. METHODS Forty human mandibular first molars were collected and randomized into four groups after establishing the distal defect: full crown group with 4 mm axial wall height (AWH) (FC4); short AWH crown group with 2 mm AWH (SC2); occlusal veneer group with 0 mm AWH (OV0); occlusal distal veneer group with only the distal surface prepared, and 4 mm AWH (OD4). The teeth were prepared according to the groups and the ceramic restorations were completed using celtra duo ceramic blocks. The ceramic thickness of the occlusal surface is about 1.5 mm and the edge is about 1 mm. The failure load values and fracture modes of each group were detected by mechanical test in vitro. According to the groups to establish three-dimensional finite element analysis (FEA) models, a 600 N loading force was applied vertically using a hemispherical indenter with a diameter of 6 mm. and compare the stress distribution under the condition of different restorations. RESULTS In vitro mechanical tests showed that the failure load values were SC2 (3232.80 ± 708.12 N) > OD4 (2886.90 ± 338.72 N) > VO0 (2133.20 ± 376.15 N) > FC4(1635.40 ± 413.05 N). The failure load values of the short AWH crown and occlusal distal veneer were significantly higher than that of occlusal veneer and full crown (P<0.05). The fracture modes of the full crown and occlusal veneer groups were mainly ceramic fractures and some were restorable tooth fractures. The short AWH crown and occlusal distal veneer groups presented with three fracture modes, the proportion of non-restorable tooth fracture was higher. The results of FEA show that under the spherical loading condition, the stress of ceramic was concentrated in the contact area of the loading head, the maximum von Mises stress values were FC4 (356.2 MPa) > VO0 (214.3 MPa) > OD4 (197.9 MPa) > SC2 (163.1 MPa). The stress of enamel was concentrated in the area where the remaining enamel was thinner, the maximum von Mises stress values was OD4 (246.2 MPa) ≈ FC4 (212.4 MPa) > VO0 (61.8 MPa) ≈ SC2 (45.81 MPa). The stress of dentin is concentrated in the root furcation and the upper third region of the root. However, stress concentration was observed at the tooth cervix in the full crown. CONCLUSION Under certain conditions, the occlusal distal veneer shows better performance than the full crown.
Collapse
Affiliation(s)
- Bin Luo
- grid.24696.3f0000 0004 0369 153XDepartment of Prosthodontics, Beijing Stomatological Hospital, School of Stomatology, Capital Medical University, 100050 Beijing, China
| | - Xiaolu Sun
- grid.479671.a0000 0004 9154 7430Shunyi Hospital, Beijing Traditional Chinese Medicine Hospital, 100010 Beijing, China
| | - Lin He
- grid.24696.3f0000 0004 0369 153XDepartment of Prosthodontics, Beijing Stomatological Hospital, School of Stomatology, Capital Medical University, 100050 Beijing, China
| | - Lidan Zhao
- grid.410737.60000 0000 8653 1072Department of Prosthodontics, Affiliated Stomatology Hospital of Guangzhou Medical University, 510013 Guangzhou, China
| | - Xinggang Liu
- grid.24696.3f0000 0004 0369 153XDepartment of Prosthodontics, Beijing Stomatological Hospital, School of Stomatology, Capital Medical University, 100050 Beijing, China
| | - Qingsong Jiang
- grid.24696.3f0000 0004 0369 153XDepartment of Prosthodontics, Beijing Stomatological Hospital, School of Stomatology, Capital Medical University, 100050 Beijing, China
| |
Collapse
|
11
|
Sirous S, Navadeh A, Ebrahimgol S, Atri F. Effect of preparation design on marginal adaptation and fracture strength of ceramic occlusal veneers: A systematic review. Clin Exp Dent Res 2022; 8:1391-1403. [PMID: 36062841 PMCID: PMC9760166 DOI: 10.1002/cre2.653] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2021] [Revised: 08/13/2022] [Accepted: 08/18/2022] [Indexed: 01/26/2023] Open
Abstract
OBJECTIVES This systematic review aims to investigate the effect of different preparation designs on the marginal fit and fracture strength of ceramic occlusal veneers. MATERIALS AND METHODS Based on the PICO question and the search terms, an electronic search was performed in Google Scholar, PubMed (MEDLINE), Scopus, Cochrane Library, Web of Science, Science Direct, Wiley, Ovid, and SAGE for articles published up to July 2022. After including English in vitro studies that evaluated posterior ceramic occlusal overlays at the posterior with ceramic restorations by following the PRISMA statement, the extracted data was tabulated. The methodological quality of the included studies was evaluated. Risk of bias assessment was done independently by two authors using the modified MINORS scale. RESULTS About 3138 search results were screened, of which 22 were selected due to their titles. Twenty-one full-text articles were assessed for eligibility. Seventeen in-vitro studies were finalized for the extraction of quantitative data. All 17 articles had a low risk of bias and were retained. The influencing items for evaluating the research were different in most studies; therefore, qualitative synthesis of the results was feasible. They generally included preparation design, material thickness, depth of preparation in the tooth, internal divergence angle, and finish line. Meta-analysis was not done due to heterogeneity of preparation types and evaluation methods. Results revealed that fracture resistance of occlusal veneers is higher than normal mastication force, and it is sufficient to prepare the occlusal surface, use a self-etching primer for bonding, and an acceptable minimum ceramic thickness. The marginal discrepancy of occlusal veneers is clinically acceptable. However, this systematic review faces some limitations due to the lack of in vivo studies, different preparation designs in included studies, different follow-ups, and lack of comprehensive explanations in articles. CONCLUSIONS The preparation design of occlusal veneers influences both marginal adaptation and fracture resistance. Various preparation designs are proven to have clinically acceptable fracture strength and marginal adaptation.
Collapse
Affiliation(s)
- Samin Sirous
- Departement of Prosthodontics, School of DentistryIslamic Azad University (Khorasgan Branch)IsfahanIran
| | | | - Saeedeh Ebrahimgol
- Department of Prosthodontics, School of DentistryTehran University of Medical SciencesTehranIran
| | - Faezeh Atri
- Department of Prosthodontics, Dental Research CenterDentistry Research Institute, Tehran University of Medical SciencesTehranIran
| |
Collapse
|
12
|
Gierthmuehlen PC, Jerg A, Fischer JB, Bonfante EA, Spitznagel FA. Posterior minimally invasive full-veneers: Effect of ceramic thicknesses, bonding substrate, and preparation designs on failure-load and -mode after fatigue. J ESTHET RESTOR DENT 2022; 34:145-153. [PMID: 34989466 DOI: 10.1111/jerd.12861] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Revised: 11/26/2021] [Accepted: 12/17/2021] [Indexed: 11/30/2022]
Abstract
OBJECTIVE To evaluate the effect of ceramic thicknesses, bonding surface (enamel vs. dentin), and preparation design (box vs. no box) on the fatigue survival and failure load of minimally invasive full-veneer restorations. MATERIALS AND METHODS Human-premolars (n = 60) were divided into five test groups (n = 12). All teeth received full-veneer preparation with the following occlusal/labial thicknesses: standard: 1.5/0.8 mm; thin: 1.0/0.6 mm; ultrathin 0.5/0.4 mm. Preparations for each ceramic thickness were refined in enamel (E-1.0 and E-0.5) or dentin (D-1.5, D-1.0, and D-0.5). Control groups DB-1.5, EB-1.0, and EB-0.5 received box preparations. Monolithic lithium disilicate restorations (IPS-e.max-Press, Ivoclar Vivadent) were adhesively cemented (Syntac-Classic/Variolink-II, Ivoclar Vivadent) and subjected to cyclic mechanical loading (F = 49 N, 1.2 million cycles) with simultaneous thermocycling (5-55°C). All specimens were exposed to single load-to-failure. Pair-wise differences were calculated by using a linear regression model and Student-Newman-Keuls method (p < 0.05). RESULTS All full-veneers of group D-1.5, E-1.0, E-0.5, DB-1.5, EB-1.0, and EB-0.5 survived fatigue. Two full-veneers (D-1.0 and D-0.5) revealed cracks during fatigue, resulting in an overall fatigue survival rate of 98.1%. Mean load-to-failure values (N) were as followed: 1005 (D-1.5); 866 (D-1.0); 816 (D-0.5); 1495 (E-1.0); 1279 (E-0.5); 1129 (DB-1.5); 1087 (EB-1.0); and 833 (EB-0.5). Irrespective of ceramic thicknesses, enamel-based full-veneers resulted in higher failure loads than dentin-based restorations. Box preparation reduced the failure loads of thin and ultrathin enamel-based restorations. CONCLUSION All tested monolithic lithium disilicate full-veneer restorations exceeded physiological masticatory forces. Minimally invasive full-veneer restorations with enamel as a bonding surface and a non-retentive preparation design showed superior performance. CLINICAL SIGNIFICANCE Enamel-based non-retentive full-veneers made of monolithic lithium disilicate may serve as a reliable and esthetical minimally invasive treatment option for premolars.
Collapse
Affiliation(s)
- Petra C Gierthmuehlen
- Department of Prosthodontics, Medical Faculty and University Hospital Düsseldorf, Heinrich-Heine-University, Düsseldorf, Germany
| | - Annika Jerg
- Department of Prosthodontics, Medical Faculty and University Hospital Düsseldorf, Heinrich-Heine-University, Düsseldorf, Germany
| | | | - Estevam A Bonfante
- Department of Prosthodontics and Periodontology, Bauru School of Dentistry, University of Sao Paulo, Bauru, Brazil
| | - Frank A Spitznagel
- Department of Prosthodontics, Medical Faculty and University Hospital Düsseldorf, Heinrich-Heine-University, Düsseldorf, Germany
| |
Collapse
|
13
|
JURADO CA, MOURAD F, TREVINO DACORTES, GOUVEIA DN, HYER J, ELGREATLY A, MAHROUS AM, GARCIA-GODOY F, TSUJIMOTO A. Comparison of full and partial coverage crowns with CAD/CAM leucite reinforced ceramic blocks on fracture resistance and fractographic analysis. Dent Mater J 2022; 41:295-301. [DOI: 10.4012/dmj.2021-253] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
- Carlos A. JURADO
- Texas Tech University Health Sciences Center El Paso, Woody L. Hunt School of Dental Medicine
| | - Firas MOURAD
- Department of Care Planning and Restorative Sciences, University of Mississippi Medical Center School of Dentistry
| | | | - Diogo N. GOUVEIA
- Department of Restorative and Prosthetic Dentistry, Ohio State University College of Dentistry
| | - Jared HYER
- A.T. Still University Arizona School of Dentistry & Oral Health
| | - Amira ELGREATLY
- Department of Operative Dentistry, University of Iowa College of Dentistry
| | - Ahmed M. MAHROUS
- Department of Prosthodontics, University of Iowa College of Dentistry
| | - Franklin GARCIA-GODOY
- Department of Bioscience Research, College of Dentistry, University of Tennessee Health Science Center
| | - Akimasa TSUJIMOTO
- Department of Operative Dentistry, University of Iowa College of Dentistry
| |
Collapse
|
14
|
Ladino L, Sanjuan ME, Valdez DJ, Eslava RA. Clinical and Biomechanical Performance of Occlusal Veneers: A Scoping Review. J Contemp Dent Pract 2021; 22:1327-1337. [PMID: 35343461 DOI: 10.5005/jp-journals-10024-3226] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
AIM This manuscript aims to evaluate, through a scoping review, current knowledge of the biomechanical behavior, materials, preparations, and limitations of occlusal veneers. BACKGROUND Occlusal veneers are a minimally invasive alternative for the additive restoration of posterior teeth with significant loss of the occlusal structure. This type of restoration has been emerged in recent years as an alternative to invasive treatment, which in the same way seeks to restore the structure of the posterior teeth. All this is because in recent years restorative dentistry has focused a large part of its objectives on conservative therapies. REVIEW RESULTS Five electronic databases-PubMed, Cochrane, LILACS, EMBASE, and Google Scholar-were searched. Title and abstracts were independently screened by three reviewers, followed by a full-text review. A total of 42 articles met our inclusion criteria; most of these studies were in vitro (n = 35) and other studies were clinical studies (n = 7). These in vitro studies included 21 studies that analyzed the type of preparation and 6 studies that evaluated the limitations of occlusal veneers. CONCLUSION Thicknesses between 0.7 and 1.0 mm are recommended for ceramic materials; in addition, thicknesses less than 0.7 mm are recommended to use polymeric materials. The materials used for this type of restoration are plastic- and ceramic-based materials, whose load resistance values were found to exceed 2000 N in most studies. It is recommended to carry out a minimally invasive preparation or not to carry out a dental preparation, as long as there is a peripheral enamel to make an external bevel that redirects the eccentric forces to the axis of the tooth. CLINICAL SIGNIFICANCE Restorative dentistry has moved toward conservative treatments with the least amount of dental tissue being removed. Occlusal veneers appear to be a conservative option in the reconstruction of tooth tissues lost due to tooth wear and in cases where it is necessary to restore or increase the vertical dimension.
Collapse
Affiliation(s)
- LuisGabriel Ladino
- LuisGabriel Ladino, Department of Prosthodontics, Institución Universitaria Colegios de Colombia (UNICOC), Bogota, DC, Colombia, Phone: +57 3057979215, e-mail:
| | - Martin Eduardo Sanjuan
- Department of Prosthodontics, Institución Universitaria Colegios de Colombia (UNICOC), Bogota, DC, Colombia
| | - Darell Josué Valdez
- Department of Prosthodontics, Institución Universitaria Colegios de Colombia (UNICOC), Bogota, DC, Colombia
| | - Rosa Angelica Eslava
- Department of Prosthodontics, Institución Universitaria Colegios de Colombia (UNICOC), Bogota, DC, Colombia
| |
Collapse
|
15
|
Al-Zordk W, Saudi A, Abdelkader A, Taher M, Ghazy M. Fracture Resistance and Failure Mode of Mandibular Molar Restored by Occlusal Veneer: Effect of Material Type and Dental Bonding Surface. MATERIALS 2021; 14:ma14216476. [PMID: 34772003 PMCID: PMC8585144 DOI: 10.3390/ma14216476] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Revised: 10/21/2021] [Accepted: 10/26/2021] [Indexed: 11/16/2022]
Abstract
This study assesses the effect of the material type (lithium disilicate, zirconia, and polymer-infiltrated ceramic) and dental bonding substrates (dentin, dentin with intra-coronal cavity, and dentin with composite filling) on the fracture resistance and failure mode of molars restored by occlusal veneers. Methods: Ninety occlusal veneers, fabricated from either lithium disilicate, zirconia, or polymer-infiltrated ceramic, were adhesively bonded to teeth prepared with either dentin, dentin with intra-coronal cavity, or dentin with composite filling. All specimens were thermally aged (5000 cycles), then load cycled (120,000 cycles). Each specimen was subjected to a compressive load through fracture, then was examined (×20) to identify the fracture type. Data were statistically analyzed. Results: Material type and dental substrate had no significant effect on the fracture resistance of adhesively retained occlusal veneer restorations. For each material, no significant differences were found between veneers bonded to dentin, dentin with intra-coronal cavity, and dentin with composite filling. Additionally, within each bonding substrate, there were no significant differences between lithium disilicate, zirconia, and polymer-infiltrated ceramic veneers. The adhesive failure was recorded mainly with zirconia occlusal veneer restorations. Conclusions: Considering the fracture results, lithium disilicate, zirconia, and polymer-infiltrated ceramic occlusal veneers perform well whatever the type of dental bonding surface. When the dental bonding surface varies, different occlusal veneer materials should be considered. Occlusal veneers bonded to dentin, dentin with composite filling, or dentin with an intra-coronal cavity exhibited a fracture resistance exceeding the average human masticatory forces in the molar area.
Collapse
Affiliation(s)
- Walid Al-Zordk
- Fixed Prosthodontics Department, Faculty of Dentistry, Mansoura University, Mansoura 35516, Egypt; (A.S.); (A.A.); (M.G.)
- Fixed Prosthodontics Department, Faculty of Dentistry, Horus University, Damietta 34511, Egypt
- Correspondence: ; Tel.: +2-010-0890-6074
| | - Alaa Saudi
- Fixed Prosthodontics Department, Faculty of Dentistry, Mansoura University, Mansoura 35516, Egypt; (A.S.); (A.A.); (M.G.)
| | - Abdelraheem Abdelkader
- Fixed Prosthodontics Department, Faculty of Dentistry, Mansoura University, Mansoura 35516, Egypt; (A.S.); (A.A.); (M.G.)
| | - Mansoura Taher
- Conservative Dentistry Department, Faculty of Dentistry, Mansoura University, Mansoura 35516, Egypt;
| | - Mohamed Ghazy
- Fixed Prosthodontics Department, Faculty of Dentistry, Mansoura University, Mansoura 35516, Egypt; (A.S.); (A.A.); (M.G.)
| |
Collapse
|