1
|
Watson JC, Lien W, Raimondi CJ, Arnason SC, Vandewalle KS. In Vitro Microleakage and Fracture Resistance of "Infinity Edge" and Cusp Reduction Preparation Designs for Moderate-sized Class II Composites. J Contemp Dent Pract 2024; 25:3-9. [PMID: 38514424 DOI: 10.5005/jp-journals-10024-3628] [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] [Indexed: 03/23/2024]
Abstract
AIM This study aimed to evaluate the marginal microleakage and maximum occlusal fracture loads and fracture modes of two novel class II preparation designs, "infinity edge" and the "2.5 mm cusp reduction" preparations as compared to a traditional class II preparation without cuspal involvement. MATERIALS AND METHODS Thirty extracted human mandibular molars were prepared for moderate-sized class II restorations with extensions into all occlusal grooves. Of these, ten class II preparations served as control. Ten were modified for a 2.5 mm even reduction of the cusps adjacent to the interproximal box. An additional 10 preparations were modified with an "infinity edge" bevel on the interproximal and occlusal portions. All teeth were restored utilizing a flowable bulk-fill composite in the apical portion of the interproximal box and 2-4 mm of heated bulk-fill composite in one increment for the remainder. All groups were cyclic loaded and thermocycled, then imaged with microcomputed tomography (µCT) before and after infiltration with a silver nitrate solution. Images were subtracted to obtain volumetric measurements of microleakage and reported as a percentage of the total volume from the apical extent of the proximal box. All groups were loaded to failure and fracture load and mode were recorded. RESULTS No significant differences were found in microleakage volume as a percentage of total tooth volume; however, the "infinity edge" group had significantly greater microleakage in the proximal box compared to the traditional class II group. No significant differences were found in fracture load or mode between the groups. CONCLUSION Traditional class II, 2.5 mm cuspal reduction, and "infinity edge" preparation designs have similar fracture loads as well as volumes of microleakage; however, an "infinity edge" preparation has a higher ratio of microleakage in the proximal box. CLINICAL SIGNIFICANCE Clinicians should carefully consider the use of "infinity edge" margins, particularly on dentin in the apical extent of the proximal box. How to cite this article: Watson JC, Lien W, Raimondi JC, et al. In Vitro Microleakage and Fracture Resistance of "Infinity Edge" and Cusp Reduction Preparation Designs for Moderate-sized Class II Composites. J Contemp Dent Pract 2024;25(1):3-9.
Collapse
Affiliation(s)
- Jill C Watson
- Department of General Dentistry, Advanced Education in General Dentistry Residency, Wright-Patterson Air Force Base, Ohio; Uniformed Services University of the Health Sciences, Bethesda, Maryland, United States of America
| | - Wen Lien
- Department of Research, Dental Materials Research, USAF Dental Research and Consultation Service, Joint Base San Antonio - Fort Sam Houston, Texas; Uniformed Services University of the Health Sciences, Bethesda, Maryland, United States of America
| | - Christopher J Raimondi
- Department of Research, Dental Materials Research, USAF Dental Research and Consultation Service, Joint Base San Antonio - Fort Sam Houston, Texas; Uniformed Services University of the Health Sciences, Bethesda, Maryland, United States of America
| | - Stephen C Arnason
- Department of General Dentistry, Advanced Education in General Dentistry Residency, Travis Air Force Base, California; Uniformed Services University of the Health Sciences, Bethesda, Maryland, United States of America
| | - Kraig S Vandewalle
- Department of General Dentistry, Advanced Education in General Dentistry Residency, AF Postgraduate Dental School, Joint Base San Antonio - Lackland, Texas; Uniformed Services University of the Health Sciences, Bethesda, Maryland, United States of America, Phone: +1 (210) 292-0760, e-mail:
| |
Collapse
|
2
|
Yang B, Aregawi W, Chen R, Zhang L, Wang Y, Fok A. Accelerated Fatigue Model for Predicting Composite Restoration Failure. J Dent Res 2022; 101:1606-1612. [PMID: 36199249 PMCID: PMC9703530 DOI: 10.1177/00220345221126928] [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] [Indexed: 11/17/2022] Open
Abstract
An empirical method is proposed to predict the clinical performance of resin composite dental restorations by using laboratory data derived from simple specimens subjected to chemical degradation and accelerated cyclic fatigue. Three resin composites were used to fill dentin disks (2-mm inner diameter, 5-mm outer diameter, and 2 mm thick) made from bovine incisor roots. The specimens (n = 30 per group) were aged with different durations of a low-pH challenge (0, 24, and 48 h under pH 4.5) before being subjected to diametral compression with either a monotonically increasing load (fast fracture) or a cyclic load with a continuously increasing amplitude (accelerated fatigue). The data from 1 material were used to establish the relationship between laboratory time (number of cycles) and clinical time to failure (years) via the respective survival probability curves. The temporal relationship was then used to predict the clinical rates of failure for restorations made of the other 2 materials, and the predictions were compared with the clinical data to assess their accuracy. Although there were significant differences in the fast fracture strength among the groups of materials or durations of chemical challenge, fatigue testing was much better at separating the groups. Linear relationships were found between the laboratory and clinical times to failure for the first material (R2 = 0.90, 0.90, and 0.62 for the 0-, 24-, and 48-h low-pH groups, respectively). The clinical life of restorations made of the other 2 materials was best predicted with data from the 48-h low-pH groups. In conclusion, an accelerated fatigue model was successfully calibrated and applied to predict the clinical failure of resin composite restorations, and the predictions based on data obtained from chemically aged specimens provided the best agreement with clinical data.
Collapse
Affiliation(s)
- B. Yang
- Hospital of Stomatology, Guanghua School of Stomatology, Sun Yat-sen University; Guangdong Provincial Key Laboratory of Stomatology, Guangzhou, China
| | - W. Aregawi
- Minnesota Dental Research Center for Biomaterials and Biomechanics, School of Dentistry, University of Minnesota, Minneapolis, MN, USA
| | - R. Chen
- Minnesota Dental Research Center for Biomaterials and Biomechanics, School of Dentistry, University of Minnesota, Minneapolis, MN, USA
| | - L. Zhang
- Divison of Biostatistics, School of Public Health, University of Minnesota, Minneapolis, MN, USA
| | - Y. Wang
- Hospital of Stomatology, Guanghua School of Stomatology, Sun Yat-sen University; Guangdong Provincial Key Laboratory of Stomatology, Guangzhou, China
| | - A.S.L. Fok
- Minnesota Dental Research Center for Biomaterials and Biomechanics, School of Dentistry, University of Minnesota, Minneapolis, MN, USA
| |
Collapse
|
3
|
Moussa DG, Sharma AK, Mansour TA, Witthuhn B, Perdigão J, Rudney JD, Aparicio C, Gomez A. Functional signatures of ex-vivo dental caries onset. J Oral Microbiol 2022; 14:2123624. [PMID: 36189437 PMCID: PMC9518263 DOI: 10.1080/20002297.2022.2123624] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Revised: 08/09/2022] [Accepted: 08/18/2022] [Indexed: 11/18/2022] Open
Abstract
Background The etiology of dental caries remains poorly understood. With the advent of next-generation sequencing, a number of studies have focused on the microbial ecology of the disease. However, taxonomic associations with caries have not been consistent. Researchers have also pursued function-centric studies of the caries microbial communities aiming to identify consistently conserved functional pathways. A major question is whether changes in microbiome are a cause or a consequence of the disease. Thus, there is a critical need to define conserved functional signatures at the onset of dental caries. Methods Since it is unethical to induce carious lesions clinically, we developed an innovative longitudinal ex-vivo model integrated with the advanced non-invasive multiphoton second harmonic generation bioimaging to spot the very early signs of dental caries, combined with 16S rRNA short amplicon sequencing and liquid chromatography-mass spectrometry-based targeted metabolomics. Findings For the first time, we induced longitudinally monitored caries lesions validated with the scanning electron microscope. Consequently, we spotted the caries onset and, associated with it, distinguished five differentiating metabolites - Lactate, Pyruvate, Dihydroxyacetone phosphate, Glyceraldehyde 3-phosphate (upregulated) and Fumarate (downregulated). Those metabolites co-occurred with certain bacterial taxa; Streptococcus, Veillonella, Actinomyces, Porphyromonas, Fusobacterium, and Granulicatella, regardless of the abundance of other taxa. Interpretation These findings are crucial for understanding the etiology and dynamics of dental caries, and devising targeted interventions to prevent disease progression.
Collapse
Affiliation(s)
- Dina G. Moussa
- Minnesota Dental Research Center for Biomaterials and Biomechanics, Department of Restorative Sciences, School of Dentistry, University of Minnesota, Minneapolis, Minnesota, USA
- Department of Animal Science, College of Food, Agriculture and Natural Resource Sciences, University of Minnesota, St Paul, Minnesota, USA
| | - Ashok K. Sharma
- Department of Animal Science, College of Food, Agriculture and Natural Resource Sciences, University of Minnesota, St Paul, Minnesota, USA
| | - Tamer A Mansour
- Department of Population Health and Reproduction, School of Veterinary Medicine, University of California, Davis, CA, USA
- Department of Clinical Pathology, School of Medicine, Mansoura University, Mansoura, Egypt
| | - Bruce Witthuhn
- Center for Mass Spectrometry and Proteomics, Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, Minnesota, USA
| | - Jorge Perdigão
- Department of Restorative Sciences, School of Dentistry, University of Minnesota, Minneapolis, Minnesota, USA
| | - Joel D. Rudney
- Department of Diagnostic and Biological Sciences, School of Dentistry, University of Minnesota, Minneapolis, Minnesota, USA
| | - Conrado Aparicio
- Minnesota Dental Research Center for Biomaterials and Biomechanics, Department of Restorative Sciences, School of Dentistry, University of Minnesota, Minneapolis, Minnesota, USA
- Department of Restorative Sciences, School of Dentistry, University of Minnesota, Minneapolis, Minnesota, USA
| | - Andres Gomez
- Department of Animal Science, College of Food, Agriculture and Natural Resource Sciences, University of Minnesota, St Paul, Minnesota, USA
| |
Collapse
|
4
|
Kumar D, Bolskar RD, Mutreja I, Jones RS. Methacrylate Polymers With “Flipped External” Ester Groups: A Review. FRONTIERS IN DENTAL MEDICINE 2022. [DOI: 10.3389/fdmed.2022.923780] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Current resin composites have favorable handling and upon polymerization initial physical properties that allow for efficient material replacement of removed carious tooth structure. Dental resin composites have long term durability limitations due to the hydrolysis of ester bonds within the methacrylate based polymer matrix. This article outlines the importance of ester bonds positioned internal to the carbon-carbon double bond in current methacrylate monomers. Water and promiscuous salivary/bacterial esterase activity can initiate ester bond hydrolysis that can sever the polymer backbone throughout the material. Recent studies have custom synthesized, with the latest advances in modern organic chemical synthesis, a novel molecule named ethylene glycol bis (ethyl methacrylate) (EGEMA). EGEMA was designed to retain the reactive acrylate units. Upon intermolecular polymerization of vinyl groups, EGEMA ester groups are positioned outside the backbone of the polymer chain. This review highlights investigation into the degradation resistance of EGEMA using buffer, esterase, and microbial storage assays. Material samples of EGEMA had superior final physical and mechanical properties than traditional ethylene glycol dimethacrylate (EGDMA) in all degradation assays. Integrating bioinformatics-based biodegradation predictions to the experimental results of storage media analyzed by LC/GC-MS revealed that hydrolysis of EGEMA generated small amounts of ethanol while preserving the strength bearing polymer backbone. Prior studies support investigation into additional custom synthesized methacrylate polymers with “flipped external” ester groups. The long term goal is to improve clinical durability compared to current methacrylates while retaining inherent advantages of acrylic based chemistry, which may ease implementation of these novel methacrylates into clinical practice.
Collapse
|
5
|
Arora RK, Mordan NJ, Spratt DA, Ng YL, Gulabivala K. Bacteria in the cavity-restoration interface after varying periods of clinical service - SEM description of distribution and 16S rRNA gene sequence identification of isolates. Clin Oral Investig 2022; 26:5029-5044. [PMID: 35359188 PMCID: PMC9276561 DOI: 10.1007/s00784-022-04473-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Accepted: 03/21/2022] [Indexed: 11/03/2022]
Abstract
OBJECTIVES To use extracted human teeth with amalgam (n = 26) or GIC (n = 3) restorations in service up to 20 years to evaluate microbiota at the cavity/restoration interface by SEM or culture. MATERIALS AND METHODS Extracted teeth with intracoronal restorations (n = 20) of known history (2-20 years) were fixed, split, and prepared for SEM to ascertain the pattern and structure of bacterial aggregates on cavity and restoration surfaces. Another 9 teeth were anaerobically decontaminated, split and sampled (cavity/restorations), and cultured (anaerobically, aerobically); recovered isolates were identified by 16S rRNA gene sequencing. RESULTS SEM showed rods, cocci, and filaments in 11/20 teeth (55%) on cavity and corresponding restoration surfaces; 4/20 (20%) on neither surface; 1/20 (5%) on just cavity; and 4/20 (20%) on just restoration. Microbial growth extended from marginal openings into the deeper interfacial microspace to varying extents but was not always evident. Restoration size or age did not predict bacterial presence. Bacteria-free surfaces (cavity/amalgam) showed possible calcification. Cultivation yielded 160 isolates, mainly Gram-positive (86%) and facultative (81%); and morphotypes of rods (43%), cocci (36%), and cocco-bacilli (18%) belonging to Actinobacteria (45%) and Firmicutes (50%). The most frequent genera were Staphylococcus, Streptococcus, Actinomyces, and Lactobacillus. Biofilms on cavity and restoration appeared independent of each other. CONCLUSIONS Cavity and amalgam surfaces were independently colonised and some not. The penetration of microbiota into marginal gaps varied; resembled root caries and was dominated by Gram-positive species. CLINICAL RELEVANCE Marginal gaps around restorations are unavoidable but are not always colonised by bacteria after long-term clinical service. Calcification of biofilms in the restorative interface may prevent further colonisation. The viable microbiota in the restorative interface resembled root caries and may be subject to ecological fluxes of activity and arrest and therefore preventative management.
Collapse
Affiliation(s)
- Roopinder Kaur Arora
- Unit of Endodontology, Departments of Restorative Dentistry, Microbial Diseases, UCL Eastman Dental Institute, University College London, Bloomsbury Campus, Rockefeller Building, 21 University Street, London, WC1E 6DE, UK
| | - Nicola J Mordan
- Biomaterials and Tissue Engineering, UCL Eastman Dental Institute, University College London, London, UK
| | - David A Spratt
- Unit of Endodontology, Departments of Restorative Dentistry, Microbial Diseases, UCL Eastman Dental Institute, University College London, Bloomsbury Campus, Rockefeller Building, 21 University Street, London, WC1E 6DE, UK
| | - Yuan Ling Ng
- Unit of Endodontology, Departments of Restorative Dentistry, Microbial Diseases, UCL Eastman Dental Institute, University College London, Bloomsbury Campus, Rockefeller Building, 21 University Street, London, WC1E 6DE, UK
| | - Kishor Gulabivala
- Unit of Endodontology, Departments of Restorative Dentistry, Microbial Diseases, UCL Eastman Dental Institute, University College London, Bloomsbury Campus, Rockefeller Building, 21 University Street, London, WC1E 6DE, UK.
| |
Collapse
|
6
|
Ordinola-Zapata R, Lin F, Nagarkar S, Perdigão J. A critical analysis of research methods and experimental models to study the load capacity and clinical behavior of the root filled teeth. Int Endod J 2022; 55 Suppl 2:471-494. [PMID: 35263455 PMCID: PMC9314814 DOI: 10.1111/iej.13722] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Accepted: 03/04/2022] [Indexed: 12/04/2022]
Abstract
The prognosis of root‐filled teeth depends not only on a successful root canal treatment but also on the restorative prognosis. This critical review discusses the advantages and limitations of various methodologies used to assess the load capacity or clinical survivability of root‐filled teeth and restorations. These methods include static loading, cyclic loading, finite element analysis and randomized clinical trials. In vitro research is valuable for preclinical screening of new dental materials or restorative modalities. It also can assist investigators or industry to decide whether further clinical trials are justified. It is important that these models present high precision and accuracy, be reproducible, and present adequate outcomes. Although in vitro models can reduce confounding by controlling important variables, the lack of clinical validation (accuracy) is a downside that has not been properly addressed. Most importantly, many in vitro studies did not explore the mechanisms of failure and their results are limited to rank different materials or treatment modalities according to the maximum load capacity. An extensive number of randomized clinical trials have also been published in the last years. These trials have provided valuable insight on the survivability of the root‐filled tooth answering numerous clinical questions. However, trials can also be affected by the selected outcome and by intrinsic and extrinsic biases. For example, selection bias, loss to follow‐up and confounding. In the clinical scenario, hypothesis‐based studies are preferred over observational and retrospective studies. It is recommended that hypothesis‐based studies minimize error and bias during the design phase.
Collapse
Affiliation(s)
- Ronald Ordinola-Zapata
- Division of Endodontics, Department of Restorative Sciences, School of Dentistry, University of Minnesota, Minneapolis, MN, 55455, USA
| | - Fei Lin
- Department of Cariology and Endodontology, Peking University School and Hospital of Stomatology, Beijing, 100081, China.,Minnesota Dental Research Center for Biomaterials and Biomechanics, School of Dentistry, University of Minnesota, Minneapolis, MN, 55455, USA
| | - Sanket Nagarkar
- Park Dental Group, Minneapolis, Minnesota, and Clinical Research Assistant Professor (affiliated), Department of Restorative Sciences, University of Minnesota, Minneapolis, Minnesota, USA
| | - Jorge Perdigão
- Division of Operative Dentistry, Department of Restorative Sciences, University of Minnesota, Minneapolis, Minnesota, USA
| |
Collapse
|
7
|
In Vitro Biofilm Formation on Aryl Ketone Polymer (AKP), A New Denture Material, Compared with That on Three Traditional Dental Denture Materials. Int J Dent 2021; 2021:4713510. [PMID: 34737774 PMCID: PMC8563116 DOI: 10.1155/2021/4713510] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2020] [Revised: 09/28/2021] [Accepted: 10/01/2021] [Indexed: 12/27/2022] Open
Abstract
Control of denture plaque biofilms is a practical approach to preventing persistent oral infections such as denture stomatitis. Objectives. This study compared in vitro biofilm attachment and growth on a new denture material, Ultaire® AKP, with that on traditional denture materials including cobalt chrome (CoCr), polymethyl methacrylate (PMMA), and polyoxymethylene (POM). Methods. Microbial biofilms were grown with cultures of Candida albicans, Streptococcus mutans UA159, or a mixed Streptococcus spp. (S. mutans 700610/Streptococcus sanguinis BAA-1455) for 6 hours in a static protocol or 24 hours in a dynamic protocol for each material. Adherent biofilm cells were removed, and viable colony-forming units (CFUs) were enumerated. Confocal microscopy of the 24-hour Streptococcus spp. biofilms was used to determine biofilm mass and roughness coefficients. Results. The rank order of C. albicans attachment after 6 hours was CoCr > PMMA ∗ > Ultaire® AKP ∗ ( ∗ vs CoCr, p ≤ 0.05), and that for 24-hour biofilm growth was CoCr > Ultaire® AKP ∗ > PMMA ∗ ( ∗ vs CoCr, p ≤ 0.05). The rank order of S. mutans biofilm attachment was CoCr > POM > Ultaire® AKP ∗ > PMMA ∗ ( ∗ vs CoCr, p ≤ 0.05), and that for the 24-hour Streptococcus spp. biofilm growth was POM > Ultaire® AKP > PMMA > CoCr ∗ ( ∗ vs POM, p ≤ 0.05). Confocal images revealed structural differences in Streptococcus spp. biofilms on CoCr compared with the other test materials. Significantly lower roughness coefficients of Streptococcus spp. biofilms on Ultaire® AKP were noted, suggesting that these biofilms were less differentiated. Ultaire® AKP promoted significantly less C. albicans and S. mutans biofilm attachment than CoCr at 6 hours and C. albicans growth at 24 hours. Streptococcus spp. biofilms on Ultaire® AKP were less differentiated than those on other test materials. Conclusion. In addition to its material strength, Ultaire® AKP represents an attractive option for denture material in removable partial dentures.
Collapse
|
8
|
Montoya C, Jain A, Londoño JJ, Correa S, Lelkes PI, Melo MA, Orrego S. Multifunctional Dental Composite with Piezoelectric Nanofillers for Combined Antibacterial and Mineralization Effects. ACS APPLIED MATERIALS & INTERFACES 2021; 13:43868-43879. [PMID: 34494813 DOI: 10.1021/acsami.1c06331] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
After nearly seven decades of development, dental composite restorations continue to show limited clinical service. The triggering point for restoration failure is the degradation of the bond at the tooth-biomaterial interface from chemical, biological, and mechanical sources. Oral biofilms form at the bonded interfaces, producing enzymes and acids that demineralize hard tissues and damage the composite. Removing bacteria from bonded interfaces and remineralizing marginal gaps will increase restorations' clinical service. To address this need, we propose for the first time the use of piezoelectric nanoparticles of barium titanate (BaTiO3) as a multifunctional bioactive filler in dental resin composites, offering combined antibacterial and (re)mineralization effects. In this work, we developed and characterized the properties of dental piezoelectric resin composites, including the degree of conversion and mechanical and physical properties, for restorative applications. Moreover, we evaluated the antibacterial and mineralization responses of piezoelectric composites in vitro. We observed a significant reduction in biofilm growth (up to 90%) and the formation of thick and dense layers of calcium phosphate minerals in piezoelectric composites compared to control groups. The antibacterial mechanism was also revealed. Additionally, we developed a unique approach evaluating the bond strength of dentin-adhesive-composite interfaces subjected to simultaneous attacks from bacteria and cyclic mechanical loading operating in synergy. Our innovative bioactive multifunctional composite provides an ideal technology for restorative applications using a single filler with combined long-lasting nonrechargeable antibacterial/remineralization effects.
Collapse
Affiliation(s)
- Carolina Montoya
- Department of Oral Health Sciences, Kornberg School of Dentistry, Temple University, Philadelphia, Pennsylvania 19140, United States
| | - Anubhav Jain
- Department of Oral Health Sciences, Kornberg School of Dentistry, Temple University, Philadelphia, Pennsylvania 19140, United States
| | - Juan José Londoño
- Department of Oral Health Sciences, Kornberg School of Dentistry, Temple University, Philadelphia, Pennsylvania 19140, United States
- Bioengineering Research Group (GIB), Department of Mechanical Engineering, Universidad EAFIT, Medellin 050022, Colombia
| | - Santiago Correa
- Bioengineering Research Group (GIB), Department of Mechanical Engineering, Universidad EAFIT, Medellin 050022, Colombia
| | - Peter I Lelkes
- Bioengineering Department, College of Engineering, Temple University, Philadelphia, Pennsylvania 19122, United States
| | - Mary Anne Melo
- Division of Operative Dentistry, Department of General Dentistry, University of Maryland School of Dentistry, Baltimore, Maryland 21201, United States
| | - Santiago Orrego
- Department of Oral Health Sciences, Kornberg School of Dentistry, Temple University, Philadelphia, Pennsylvania 19140, United States
- Bioengineering Department, College of Engineering, Temple University, Philadelphia, Pennsylvania 19122, United States
| |
Collapse
|
9
|
Zhang A, Ye N, Aregawi W, Zhang L, Salah M, VanHeel B, Chew HP, Fok ASL. A Review of Mechano-Biochemical Models for Testing Composite Restorations. J Dent Res 2021; 100:1030-1038. [PMID: 34365857 DOI: 10.1177/00220345211026918] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Due to the severe mechano-biochemical conditions in the oral cavity, many dental restorations will degrade and eventually fail. For teeth restored with resin composite, the major modes of failure are secondary caries and fracture of the tooth or restoration. While clinical studies can answer some of the more practical questions, such as the rate of failure, fundamental understanding on the failure mechanism can be obtained from laboratory studies using simplified models more effectively. Reviewed in this article are the 4 main types of models used to study the degradation of resin-composite restorations, namely, animal, human in vivo or in situ, in vitro biofilm, and in vitro chemical models. The characteristics, advantages, and disadvantages of these models are discussed and compared. The tooth-restoration interface is widely considered the weakest link in a resin composite restoration. To account for the different types of degradation that can occur (i.e., demineralization, resin hydrolysis, and collagen degradation), enzymes such as esterase and collagenase found in the oral environment are used, in addition to acids, to form biochemical models to test resin-composite restorations in conjunction with mechanical loading. Furthermore, laboratory tests are usually performed in an accelerated manner to save time. It is argued that, for an accelerated multicomponent model to be representative and predictive in terms of both the mode and the speed of degradation, the individual components must be synchronized in their rates of action and be calibrated with clinical data. The process of calibrating the in vitro models against clinical data is briefly described. To achieve representative and predictive in vitro models, more comparative studies of in vivo and in vitro models are required to calibrate the laboratory studies.
Collapse
Affiliation(s)
- A Zhang
- Minnesota Dental Research Center for Biomaterials and Biomechanics, School of Dentistry, University of Minnesota, Minneapolis, MN, USA
| | - N Ye
- Minnesota Dental Research Center for Biomaterials and Biomechanics, School of Dentistry, University of Minnesota, Minneapolis, MN, USA
| | - W Aregawi
- Minnesota Dental Research Center for Biomaterials and Biomechanics, School of Dentistry, University of Minnesota, Minneapolis, MN, USA
| | - L Zhang
- Minnesota Dental Research Center for Biomaterials and Biomechanics, School of Dentistry, University of Minnesota, Minneapolis, MN, USA.,The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) & Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology, Wuhan University, Wuhan, China
| | - M Salah
- Minnesota Dental Research Center for Biomaterials and Biomechanics, School of Dentistry, University of Minnesota, Minneapolis, MN, USA.,Faculty of Dentistry, Ain-Shams University, Cairo, Egypt
| | - B VanHeel
- Minnesota Dental Research Center for Biomaterials and Biomechanics, School of Dentistry, University of Minnesota, Minneapolis, MN, USA
| | - H P Chew
- Minnesota Dental Research Center for Biomaterials and Biomechanics, School of Dentistry, University of Minnesota, Minneapolis, MN, USA
| | - A S L Fok
- Minnesota Dental Research Center for Biomaterials and Biomechanics, School of Dentistry, University of Minnesota, Minneapolis, MN, USA
| |
Collapse
|
10
|
Ordinola-Zapata R, Fok ASL. Research that matters: debunking the myth of the "fracture resistance" of root filled teeth. Int Endod J 2021; 54:297-300. [PMID: 33570814 DOI: 10.1111/iej.13479] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- R Ordinola-Zapata
- Division of Endodontics, Department of Restorative Sciences, University of Minnesota, Minneapolis, MN, USA
| | - A S L Fok
- MDRCBB-Minnesota Dental Research Center for Biomaterials and Biomechanics, Department of Restorative Sciences, School of Dentistry, University of Minnesota, Minneapolis, MN, USA
| |
Collapse
|
11
|
Zhou Y, Matin K, Shimada Y, Wang G, Sadr A, Tagami J. Detection and analysis of early degradation at resin-dentin interface by optical coherence tomography (OCT) and confocal laser scanning microscope (CLSM). J Dent 2021; 106:103583. [PMID: 33450311 DOI: 10.1016/j.jdent.2021.103583] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2020] [Revised: 01/06/2021] [Accepted: 01/07/2021] [Indexed: 01/21/2023] Open
Abstract
OBJECTIVE To evaluate early degradation at resin-dentin interface using non-invasive swept-source optical coherence tomography (SS-OCT) and confocal laser scanning microscope (CLSM). METHODS Self-etch adhesives and resin-composites containing bisphenol-glycidyl-dimethacrylate (Bis-GMA), which is one of the most widely used monomers in restorative materials, were investigated in this study. Forty cervical cavities were prepared in bovine incisors and applied by the adhesive with/without Bis-GMA (AdhesiveBG/Adhesive), filled by the resin with/without Bis-GMA (ResinBG/Resin) and then challenged by cariogenic biofilm (37 °C, 24 h). Gap Formation and dentin demineralization around resin-composites were observed by SS-OCT and CLSM. RESULTS Three types of resin-dentin interfacial degradation could be detected from SS-OCT. Type I-dentin demineralization around resin without gap, showing feather-shaped dark zones without bright scattered lines at resin-dentin interfaces. Type II-dentin demineralization around resin with adhesive-dentin bonded gaps, showing feather-shaped dark zones with bright scattered lines at resin-dentin interfaces. Type III-dentin demineralization around resin with adhesive-dentin debonded gaps, showing edge-shaped dark zones with bright scattered lines at resin-dentin interface. From CLSM, the groups were compared in gap scale (GS), gap depth (GD), gap width (GW) and dentin wall lesion depth (WLD). Bis-GMA-containing adhesive groups showed significantly lower GS than Bis-GMA-free adhesive groups. Bis-GMA-containing resin groups showed significantly lower WLD than Bis-GMA-free resin groups. However, they did not show significant differences in GD and GW. CONCLUSION Three types of early degradation at resin-dentin interface can be noninvasively detected by SS-OCT. Bis-GMA-containing and Bis-GMA-free restorative materials show differences in gap scale and dentin wall lesion depth. CLINICAL SIGNIFICANCE SS-OCT can nondestructively detect early resin-dentin interfacial degradation. Gap scale can be used as a parameter to evaluate the risk factor of gaps.
Collapse
Affiliation(s)
- Yuan Zhou
- Laboratory of Molecular and Preventive Dentistry, Department of Preventive Dentistry, Shanghai Ninth People's Hospital, Shanghai JiaoTong University School of Medicine, 639 Zhizaoju Road, Huangpu District, 200011, Shanghai, China.
| | - Khairul Matin
- Department of Cariology and Operative Dentistry, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan; Endowed Department of International Oral Health Science (Affiliated With Department of Translational Research), School of Dental Medicine, Tsurumi University, Yokohama, Kanagawa, Japan
| | - Yasushi Shimada
- Department of Operative Dentistry, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan
| | - Guoqing Wang
- Department of Electrical and Electronic Engineering, Southern University of Science and Technology, Shenzhen, Guangdong, China
| | - Alireza Sadr
- Biomimetics Biomaterials Biophotonics & Technology Laboratory, Department of Restorative Dentistry, University of Washington School of Dentistry, Seattle, WA, USA
| | - Junji Tagami
- Department of Cariology and Operative Dentistry, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan.
| |
Collapse
|
12
|
Polymeric nanoparticles protect the resin-dentin bonded interface from cariogenic biofilm degradation. Acta Biomater 2020; 111:316-326. [PMID: 32439613 DOI: 10.1016/j.actbio.2020.05.002] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Revised: 04/30/2020] [Accepted: 05/02/2020] [Indexed: 12/15/2022]
Abstract
The objective was to assess doxycycline (Dox) and zinc (Zn) doped nanoparticles' (NPs) potential to protect the resin-dentin interface from cariogenic biofilm. Three groups of polymeric NPs were tested: unloaded, loaded with zinc and with doxycycline. NPs were applied after dentin etching. The disks were exposed to a cariogenic biofilm challenge in a Drip-Flow Reactor during 72 h and 7 d. Half of the specimens were not subjected to biofilm formation but stored 72 h and 7 d. LIVE/DEAD® viability assay, nano-dynamic mechanical assessment, Raman spectroscopy and field emission electron microscopy (FESEM) analysis were performed. The measured bacterial death rates, at 7 d were 46% for the control group, 51% for the undoped-NPs, 32% for Dox-NPs, and 87% for Zn-NPs; being total detected bacteria reduced five times in the Dox-NPs group. Zn-NPs treated samples reached, in general, the highest complex modulus values at the resin-dentin interface over time. Regarding the mineral content, Zn-NPs-treated dentin interfaces showed the highest mineralization degree associated to the phosphate peak and the relative mineral concentration. FESEM images after Zn-NPs application permitted to observe remineralization of the etched and non-resin infiltrated collagen layer, and bacteria were scarcely encountered. The combined antibacterial and remineralizing effects, when Zn-NPs were applied, reduced biofilm formation. Dox-NPs exerted an antibacterial role but did not remineralize the bonded interface. Undoped-NPs did not improve the properties of the interfaces. Application of Zn-doped NPs during the bonding procedure is encouraged. STATEMENT OF SIGNIFICANCE: Application of Zn-doped nanoparticles on acid etched dentin reduced biofilm formation and viability at the resin-dentin interface due to both remineralization and antibacterial properties. Doxycycline-doped nanoparticles also diminished oral biofilm viability, but did not remineralize the resin-dentin interface.
Collapse
|
13
|
Jain A, Armstrong SR, Banas JA, Qian F, Maia RR, Teixeira EC. Dental adhesive microtensile bond strength following a biofilm-based in vitro aging model. J Appl Oral Sci 2020; 28:e20190737. [PMID: 32609185 PMCID: PMC7340208 DOI: 10.1590/1678-7757-2019-0737] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Accepted: 05/11/2020] [Indexed: 11/22/2022] Open
Abstract
OBJECTIVE Laboratory tests are routinely used to test bonding properties of dental adhesives. Various aging methods that simulate the oral environment are used to complement these tests for assessment of adhesive bond durability. However, most of these methods challenge hydrolytic and mechanical stability of the adhesive- enamel/dentin interface, and not the biostability of dental adhesives. To compare resin-dentin microtensile bond strength (μTBS) after a 15-day Streptococcus mutans (SM) or Streptococcus sobrinus (SS) bacterial exposure to the 6-month water storage (WS) ISO 11405 type 3 test. METHODOLOGY A total of 31 molars were flattened and their exposed dentin was restored with Optibond-FL adhesive system and Z-100 dental composite. Each restored molar was sectioned and trimmed into four dumbbell-shaped specimens, and randomly distributed based on the following aging conditions: A) 6 months of WS (n=31), B) 5.5 months of WS + 15 days of a SM-biofilm challenge (n=31), C) 15 days of a SM-biofilm challenge (n=31) and D) 15 days of a SS-biofilm challenge (n=31). μTBS were determined and the failure modes were classified using light microscopy. RESULTS Statistical analyses showed that each type of aging condition affected μTBS (p<0.0001). For Group A (49.7±15.5MPa), the mean μTBS was significantly greater than in Groups B (19.3±6.3MPa), C (19.9±5.9MPa) and D (23.6±7.9MPa). For Group D, the mean μTBS was also significantly greater than for Groups B and C, but no difference was observed between Groups B and C. CONCLUSION A Streptococcus mutans- or Streptococcus sobrinus-based biofilm challenge for 15 days resulted in a significantly lower μTBS than did the ISO 11405 recommended 6 months of water storage. This type of biofilm-based aging model seems to be a practical method for testing biostability of resin-dentin bonding.
Collapse
Affiliation(s)
- Aditi Jain
- University of Iowa, Department of Operative Dentistry, Iowa City, IA, USA
| | - Steve R Armstrong
- University of Iowa, Department of Operative Dentistry, Iowa City, IA, USA
| | - Jeffrey A Banas
- University of Iowa, Iowa Institute for Oral Health Research, Iowa City, IA, USA
| | - Fang Qian
- University of Iowa, Iowa Institute for Oral Health Research, Iowa City, IA, USA
| | - Rodrigo R Maia
- University of Iowa, Department of Operative Dentistry, Iowa City, IA, USA
| | - Erica C Teixeira
- University of Iowa, Department of Operative Dentistry, Iowa City, IA, USA
| |
Collapse
|
14
|
Zhang A, Chen R, Aregawi W, He Y, Wang S, Aparicio C, Rudney J, Chew HP, Fok AS. Development and calibration of biochemical models for testing dental restorations. Acta Biomater 2020; 109:132-141. [PMID: 32289496 PMCID: PMC7244368 DOI: 10.1016/j.actbio.2020.04.014] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Revised: 04/03/2020] [Accepted: 04/07/2020] [Indexed: 02/07/2023]
Abstract
Currently, resin composites are the most popular materials for dental restoration in clinical practice. Although the properties of such materials have been improved significantly, together with better clinical techniques used for their placement, early restoration failure still occurs too frequently. As clinical studies take years to complete, and new resin composites are being produced at ever increasing pace, laboratory assessment using accelerated but representative tests is necessary. The main types of failure in resin-composite restoration are tooth/restoration fracture and secondary caries, which are caused by a combination of mechanical and biochemical challenges. In this study, a biofilm model (S. mutans) and a chemical model (lactic-acid buffer) for producing artificial caries in bovine dentin are developed and calibrated against in situ data. Using a power law relationship between the demineralization depth and challenge duration, scale factors that convert the in vitro durations to the equivalent clinical durations are determined for different pH values for each model. The scale factors will allow the synchronization of biochemical and mechanical challenges in terms of their rates of action to potentially test resin-composite restoration in an accelerated but clinically representative manner. STATEMENT OF SIGNIFICANCE: Although the properties of resin composites for dental restoration have been improved significantly, early restoration failure still occurs too frequently. As clinical studies take years to complete, accelerated laboratory testing is necessary. Resin-composite restoration fail mainly through fracture and secondary caries, caused by a combination of mechanical and biochemical challenges. In this study, a biofilm and a chemical model for producing artificial caries in bovine dentin are calibrated against in situ data. Using a power law relationship between demineralization depth and challenge duration, scale factors are determined for different pH for each model. The scale factors will allow the synchronization of biochemical and mechanical challenges in testing resin-composite restoration in an accelerated but clinically representative manner.
Collapse
Affiliation(s)
- Anqi Zhang
- Minnesota Dental Research Center for Biomaterials and Biomechanics (MDRCBB), School of Dentistry, University of Minnesota, 16-212 Moos Tower, 515 Delaware St. SE, Minneapolis, MN 55455, United States
| | - Ruoqiong Chen
- Department of Diagnostic and Biological Sciences, School of Dentistry, University of Minnesota, Minneapolis, MN, United States
| | - Wondwosen Aregawi
- Minnesota Dental Research Center for Biomaterials and Biomechanics (MDRCBB), School of Dentistry, University of Minnesota, 16-212 Moos Tower, 515 Delaware St. SE, Minneapolis, MN 55455, United States
| | - Yiting He
- Department of Prosthodontics, Guanghua School of Stomatology, Guangdong Provincial Key Laboratory of Stomatology, Hospital of Stomatology, Sun Yat-sen University, Guangzhou, Guangdong, People's Republic of China
| | - Shuting Wang
- Department of Stomatology, Peking University People's Hospital, Beijing, People's Republic of China
| | - Conrado Aparicio
- Minnesota Dental Research Center for Biomaterials and Biomechanics (MDRCBB), School of Dentistry, University of Minnesota, 16-212 Moos Tower, 515 Delaware St. SE, Minneapolis, MN 55455, United States
| | - Joel Rudney
- Department of Diagnostic and Biological Sciences, School of Dentistry, University of Minnesota, Minneapolis, MN, United States
| | - Hooi Pin Chew
- Minnesota Dental Research Center for Biomaterials and Biomechanics (MDRCBB), School of Dentistry, University of Minnesota, 16-212 Moos Tower, 515 Delaware St. SE, Minneapolis, MN 55455, United States
| | - Alex S Fok
- Minnesota Dental Research Center for Biomaterials and Biomechanics (MDRCBB), School of Dentistry, University of Minnesota, 16-212 Moos Tower, 515 Delaware St. SE, Minneapolis, MN 55455, United States.
| |
Collapse
|
15
|
Mergulhão VA, de Mendonça LS, de Albuquerque MS, Braz R. Fracture Resistance of Endodontically Treated Maxillary Premolars Restored With Different Methods. Oper Dent 2019; 44:E1-E11. [DOI: 10.2341/17-262-l] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
SUMMARY
Purpose:
The purpose of this in vitro study was to evaluate the resistance and patterns of fracture of endodontically treated maxillary premolars (ETPs) restored with different methods.
Methods and Materials:
Mesio-occluso-distal cavities were prepared in 50 extracted caries-free human maxillary premolars after endodontic treatment. The teeth were divided into five groups (n=10), according to the restorative method. G1: intact teeth (control group); G2: conventional composite resin; G3: conventional composite resin with a horizontal glass fiber post inserted between buccal and palatal walls; G4: bulk-fill flowable and bulk-fill restorative composites; and G5: ceramic inlay. For direct restorations, Filtek Z350 XT, Filtek Bulk Fill Flowable Restorative, and Filtek Bulk Fill Posterior Restorative were used. Indirect restorations were fabricated from a pressable lithium disilicate glass-ceramic (IPS e-max Press) and adhesively cemented (RelyX Ultimate). All specimens were subjected to thermocycling (5°C to 55°C/5000 cycles) and additionally submitted to cyclic loading 50,000 times in an Electro-Mechanical Fatigue Machine. Next, the specimens were subjected to a compressive load at a crosshead speed of 1 mm/min until fracture. The fractured specimens were analyzed to determine the fracture pattern using a stereomicroscope, and then representative specimens were carbon coated to allow for the studying of the fracture surface under scanning electron microscopy. One-way analysis of variance (ANOVA) was used to compare fracture resistance of the groups. The results of fracture patterns were submitted to the Fisher exact test (α=0.05).
Results:
All specimens survived fatigue. Mean (standard deviation) failure loads (N) for groups were as follows: G1: 949.6 (331.5); G2: 999.6 (352.5); G3: 934.5 (233.6); G4: 771.0 (147.4); and G5: 856.7 (237.5). The lowest fracture resistance was recorded for G4, and the highest ones were recorded for G2, followed by that of G1 and G3. One-way ANOVA did not reveal significant differences between groups (p>0.05). The highest repairable fracture rates were observed in G1 (100%) and G3 (80%).
Conclusions:
ETPs restored with conventional composite resin with or without horizontal fiber post, bulk-fill composite, and ceramic inlay showed fracture resistance similar to that of sound teeth. Conventional composite resin restorations exhibited the highest prevalence of unrepairable fractures, and the insertion of a horizontal fiber post decreased this prevalence. Intact teeth showed 100% of repairable fractures. It is difficult to extrapolate the results directly to a clinical situation due to the limitations of this study.
Collapse
Affiliation(s)
- VA Mergulhão
- Viviane A Mergulhão, PhD, Department of Restorative Dentistry, University of Pernambuco, Brazil
| | - LS de Mendonça
- Luciana S de Mendonça, PhD student, University of Pernambuco, Camaragibe, Brazil
| | - MS de Albuquerque
- Mônica S de Albuquerque, PhD student, Department of Restorative Dentistry, University of Pernambuco, Brazil
| | - R Braz
- Rodivan Braz, PhD, DDS, professor, Department of Restorative Dentistry, University of Pernambuco, Camaragibe, Brazil
| |
Collapse
|