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BDJ Open Dec 2023Evaluation of the Shear bond strength over zirconia and titanium alloy and degree of conversion of extraoral compared to intraoral self-adhesive resin cements.
OBJECTIVE
Evaluation of the Shear bond strength over zirconia and titanium alloy and degree of conversion of extraoral compared to intraoral self-adhesive resin cements.
MATERIALS AND METHODS
Nine bonding protocols were carried out on zirconia 4Y-TZP and titanium alloy (Ti-6Al-4V). Seven resin cement (one extraoral and six intraoral) were tested in the shear bond strength test and the degree of conversion measurements.
RESULTS
The significantly highest value was obtained for Monobond Plus + Multilink Hybrid Abutment, the extraoral resin cement for both titanium alloy (35.1 MPa) and zirconia (32.9 MPa). For each resin, significantly higher DC values were obtained for the dual-cure mode compared with the self-cure mode. Regardless of the cure mode, Nexus Universal reached the highest DC (78.4%).
DISCUSSION/CONCLUSIONS
In this study, the extraoral self-curing resin cement showed the higher bond strength values on zirconia and titanium alloy when associated with a universal primer. Some intraoral dual-cure resin cements showed closed performances when used with universal primers. There is no direct correlation between the degree of conversion of the resin cement and the shear bond strength obtained on the prosthetic materials tested.
PubMed: 38071342
DOI: 10.1038/s41405-023-00178-0 -
Journal of Functional Biomaterials Sep 2023To regulate the degradation rate and improve the surface biocompatibility of the AZ31B magnesium alloy, three different coating systems were produced via plasma...
To regulate the degradation rate and improve the surface biocompatibility of the AZ31B magnesium alloy, three different coating systems were produced via plasma electrolytic oxidation (PEO): simple PEO, PEO incorporating multi-walled carbon nanotubes (PEO + CNT), and a duplex coating that included a polycaprolactone top layer (PEO + CNT/PCL). Surfaces were characterized by chemical content, roughness, topography, and wettability. Biological properties analysis included cell metabolism and adhesion. PEO ± CNT resulted in an augmented surface roughness compared with the base material (BM), while PCL deposition produced the smoothest surface. All surfaces had a contact angle below 90°. The exposure of gFib-TERT and bmMSC to culture media collected after 3 or 24 h did not affect their metabolism. A decrease in metabolic activity of 9% and 14% for bmMSC and of 14% and 29% for gFib-TERT was observed after 3 and 7 days, respectively. All cells died after 7 days of exposure to BM and after 15 days of exposure to coated surfaces. Saos-2 and gFib-TERT adhered poorly to BM, in contrast to bmMSC. All cells on PEO anchored into the pores with filopodia, exhibited tiny adhesion protrusions on PEO + CNT, and presented a web-like spreading with lamellipodia on PEO + CNT/PCL. The smooth and homogenous surface of the duplex PEO + CNT/PCL coating decreased magnesium corrosion and led to better biological functionality.
PubMed: 37754889
DOI: 10.3390/jfb14090475 -
The Japanese Dental Science Review Dec 2023Binary titanium-zirconium alloys have been studied as promising alternatives for Ti implants. The commercial Ti-15Zr alloy (Roxolid, Straumann) has been the major... (Review)
Review
Binary titanium-zirconium alloys have been studied as promising alternatives for Ti implants. The commercial Ti-15Zr alloy (Roxolid, Straumann) has been the major subject of numerous binary Ti-Zr alloys-related studies and has gained wide recognition in laboratory studies and clinical practices. However, binary Ti-Zr alloys of other composition ratios are still being investigated by researchers. This review aims to provide information on the potential of binary Ti-Zr alloys other than Ti-15Zr as implant materials in terms of mechanical strengths, chemical or electrochemical corrosion resistance capabilities, and biological performances. In addition, in this review, the Ti-15Zr alloy is discussed only when compared with other binary Ti-Zr alloys. From the included 26 studies, it is confirmed that the mechanical, chemical, electrochemical, and biological properties of Ti-Zr alloys are related to the Ti and Zr composition ratio in the alloy, phase, manufacturing process, and surface treatment. Among the studied alloys, α-or α' phase-Ti-5 wt, 45 wt/30at, and 50 wt. %Zr exhibited relatively more promising results for further investigation. More research is necessary to evaluate the potential for future use of these materials for implants.
PubMed: 36819742
DOI: 10.1016/j.jdsr.2023.01.002 -
Journal of Functional Biomaterials Dec 2023The interaction of different dental alloys with the oral environment may cause severe side effects (e.g., burning sensation, inflammatory reactions, carcinogenesis) as a...
The interaction of different dental alloys with the oral environment may cause severe side effects (e.g., burning sensation, inflammatory reactions, carcinogenesis) as a result of oral galvanism. However, the pathogenesis of side effects associated with oral galvanism is still unclear, and the effects of direct current and alloy corrosion ions are considered potentially contributing factors. Therefore, the aim of this study was to systemically compare the damaging effects of (1) galvanism as a synergistic process (direct current + corrosion ions), (2) direct current separately, and (3) corrosion ions separately on an in vitro mucosa-like model based on a cell line of immortalized human keratinocytes (HaCaTs) to reveal the factors playing a pivotal role in dental alloys side effects. For this, we chose and compared the dental alloys with the highest risk of oral galvanism: Ti64-AgPd and NiCr-AgPd. We showed that galvanic current may be the leading damaging factor in the cytotoxic processes associated with galvanic coupling of metallic intraoral appliances in the oral cavity, especially in the short-term period (28 days). However, the contribution of corrosion ions (Ni) to the synergistic toxicity was also shown, and quite possibly, in the long term, it could be no less dangerous.
PubMed: 38132818
DOI: 10.3390/jfb14120564 -
Dental Materials Journal Sep 2023Although dental evidence is frequently used for the identification of unidentified persons, information about the many types of alloys used in prosthetics is not...
Although dental evidence is frequently used for the identification of unidentified persons, information about the many types of alloys used in prosthetics is not utilized. If the type of alloy can be identified from a small amount of material, the scope of the search could be narrowed. In this experiment, a method was investigated for identifying the alloy type using 3 kinds of cutting points (a white point and 2 types of silicone points). Wavelength-dispersive X-ray spectroscopy (WDS) was used for elemental analysis. The elements were translated into multidimensional vectors, and the cosine similarity was calculated to compare vectors of the WDS results and vectors of the official data of alloys. According to the results, cosine similarity showed a concordance of more than 0.8. The developed program is expected to be useful as a method for identifying alloy types using only a small amount of grinding dust.
PubMed: 37558424
DOI: 10.4012/dmj.2023-068 -
Dental Materials : Official Publication... Dec 2023The objective is to compare the preventive effect on secondary caries of glass ionomer cement (GIC) restorations with amalgam or resin-composite restorations. (Meta-Analysis)
Meta-Analysis Review
OBJECTIVE
The objective is to compare the preventive effect on secondary caries of glass ionomer cement (GIC) restorations with amalgam or resin-composite restorations.
METHODS
Two independent researchers conducted a systematic search of English publications in PubMed, Web of Science, Cochrane and Scopus. They selected randomized clinical trials comparing secondary caries incidences around GIC restorations (conventional GIC or resin-modified GIC) with amalgam or resin-composite restorations. Meta-analysis of the secondary-caries incidences with risk ratio (RR) and 95% confidence interval (95% CI) as the effect measure was performed.
RESULTS
This review included 64 studies. These studies included 8310 GIC restorations and 5857 amalgam or resin-composite restorations with a follow-up period from 1 to 10 years. Twenty-one studies with 4807 restorations on primary teeth and thirty-eight studies with 4885 restorations on permanent teeth were eligible for meta-analysis. The GIC restorations had a lower secondary caries incidence compared with amalgam restorations in both primary dentition [RR= 0.55, 95% CI:0.41-0.72] and permanent dentition [RR= 0.20, 95% CI:0.11-0.38]. GIC restorations showed similar secondary caries incidence compared with resin-composite restorations in primary dentition [RR= 0.92, 95% CI:0.77-1.10] and permanent dentition [RR= 0.77, 95% CI:0.39-1.51]. Conventional GIC restorations showed similar secondary caries incidence compared with resin-modified GIC-restored teeth in both primary dentition [RR= 1.12, 95% CI:0.67-1.87] and permanent dentition [RR= 1.63, 95% CI:0.34-7.84].
CONCLUSIONS
GIC restorations showed a superior preventive effect against secondary caries compared to amalgam restorations, and a similar preventive effect against secondary caries compared to resin-composite restorations in both primary and permanent teeth. [PROSPERO Registration ID: CRD42022380959].
Topics: Humans; Dental Restoration, Permanent; Glass Ionomer Cements; Dental Caries Susceptibility; Dental Caries; Composite Resins; Dental Amalgam
PubMed: 37838608
DOI: 10.1016/j.dental.2023.10.008 -
Success and complication rates of non-precious alloy telescopic crowns in a general dental practice.Clinical Oral Investigations Dec 2023This retrospective, single-center, practice-based cohort study aimed to analyze factors associated with the success of removable partial dentures retained by telescopic...
OBJECTIVES
This retrospective, single-center, practice-based cohort study aimed to analyze factors associated with the success of removable partial dentures retained by telescopic crowns (TRPD).
MATERIALS AND METHODS
TRPD which were placed in a single practice of a practice-based research network were analyzed. Data from 139 patients (age (SD): 66 (11) years; 66 female) with 174 TRPD including 488 non-precious alloy telescopic crowns (TC) between 2004 and 2016 were included. TC without any technical complication were considered as successful, and as survived, if they were still in function at the last check-up. Multilevel Cox proportional hazard models were used to evaluate the association between clinical factors and time until failure.
RESULTS
Within a mean follow-up period (SD) of 4.2 (3.3) years (min-max: 1 day-12 years), 372 (76%) TC (AFR: 5.0%) as well as 136 (87%) TRPD (AFR: 5.1%) ("worst-case scenario") and 150 (86%) TRPD (AFR: 3.4%) ("best-case scenario") were considered as successful. The main failure types were recementation (n = 39), endodontic treatment (n = 36), and extraction (n = 35). TC in male patients showed 1.6 times higher risk for failure than in female patients (95%CI: 1.1-2.4; p = 0.023). TC on premolars showed 2.2 times higher risk for failure than on incisors (95%CI: 1.1-5.0; p = 0.023) and TC in dentures with ≤ 3TC showed 2.1 times higher risk for failure than TC in dentures with > 3TC (1.3-3.4; p = 0.042). Furthermore, TC on the most distal tooth in an arch showed 2.4 times higher risk for failure than TC on a more mesial tooth (1.5-3.8; p < 0.001).
CONCLUSION
For removable partial dentures retained by telescopic crowns, high success rates could be found after up to 12 years. Patient-level and tooth-level factors were significantly associated with failure.
CLINICAL RELEVANCE
For removable partial dentures retained by telescopic crowns, high success rates could be found after up to 12 years. Patient-level and tooth-level factors were significantly associated with failure.
Topics: Humans; Male; Female; Follow-Up Studies; Retrospective Studies; Alloys; Cohort Studies; Crowns; Denture, Partial, Removable; Dental Abutments; Dental Restoration Failure; Dental Prosthesis Design
PubMed: 37910235
DOI: 10.1007/s00784-023-05350-2 -
Dental and Medical Problems 2024Nickel-titanium (NiTi) file separation during endodontic treatment is an undesirable event. This phenomenon needs to be understood by knowing the factors influencing... (Review)
Review
Nickel-titanium (NiTi) file separation during endodontic treatment is an undesirable event. This phenomenon needs to be understood by knowing the factors influencing fracture in endodontic files. There is a large amount of literature where these factors and their influence have been studied, increasing the knowledge about the mechanisms involved, mainly related to wire technology, file shapes and geometry, operator manipulation, the anatomy of the root canal, and the irrigation and sterilization processes. As many factors are involved, the complexity of the fracture phenomena increases and the isolated correlation of one factor with the file fracture becomes a small part of comprehending the separation phenomena. This thematic review aims to compile important reports from 2014 to 2022 on the factors influencing NiTi file separation. The information obtained was classified into wire technology, file geometry, operational aspects, irrigation and sterilization, and anatomy. For this purpose, the Scopus, Web of Science and ScienceDirect databases were consulted using a search string. Filters were applied to consolidate the final set of relevant papers covering the subject of factors influencing endodontic file separation. It was found that the fracture of NiTi files incorporates different mechanisms that operate simultaneously during the endodontic procedure and strongly affect the instrument performance. The collected information promotes good practices to prevent file separation.
Topics: Nickel; Titanium; Humans; Root Canal Preparation; Equipment Failure; Equipment Design; Sterilization; Dental Instruments
PubMed: 38686969
DOI: 10.17219/dmp/156805 -
Alternative Therapies in Health and... May 2024To investigate the impact of the restoration of non-bracket invisible orthodontic titanium alloy implant on individuals with dental malocclusion and arch deficiency...
The Impact of the Restoration of Invisible Orthodontic Titanium Alloy Implant Without Bracket on Individuals Afflicted with Dental Malocclusion and Arch Deficiency Accompanied by Periodontitis and a Local Periodontal Inflammation.
OBJECTIVE
To investigate the impact of the restoration of non-bracket invisible orthodontic titanium alloy implant on individuals with dental malocclusion and arch deficiency accompanied by periodontitis and local periodontal Inflammation.
METHOD
A cohort of 120 patients presenting with dental malocclusion and defects compounded by periodontitis, were treated at our institution between January 2021 and January 2022; these patients were enrolled in a randomized controlled trial.. These patients were allocated into two groups. The control group (comprising 60 cases) underwent titanium alloy implant restoration, while the research group (also with 60 cases) received titanium alloy implant restoration following invisible orthodontic treatment without brackets. A one-year post-treatment follow-up was conducted, during which various parameters, including pain levels, aesthetic improvement, inflammatory response, dental function, oral hygiene, and the incidence of adverse events, were evaluated and compared before and after treatment between the two groups.
RESULTS
After six months of treatment, the visual analog scale (VAS) in the study group was lower than that in the control group (P < .05). After 6 months of treatment, the research team observed the changes in gingival crevicular interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), Interleuckin-1 (IL-1), plaque index (PLI), and soft dirt index (DI) were all lower than those in the control group (P < .05). After 6 months of treatment, the research group had higher scores for tooth functions such as chewing, swallowing, speech expression, and occlusion than the control group, as well as higher pink and white aesthetics indexes (P < .05). The difference in the incidence rate of adverse outcomes between the research and control group was not distinct (P > .05).
CONCLUSION
In case of dental malocclusion accompanied by periodontal disease, the utilization of titanium implants for rectifying dental arch deformities without the use of orthodontic brackets, devoid of orthodontic brackets, has demonstrated notable efficacy in alleviating patients' periodontal discomfort, their oral hygiene, and dental functionality. This modality is conducive to augmenting dental aesthetics without incurring heightened rates of unfavorable consequences, thereby enhancing treatment outcomes.
PubMed: 38702170
DOI: No ID Found -
British Dental Journal Sep 2023Aim This study aimed to explore disparities in experience of UK dental foundation trainees in amalgam use at dental school compared to their first year in dental...
Aim This study aimed to explore disparities in experience of UK dental foundation trainees in amalgam use at dental school compared to their first year in dental practice.Methods A modified version of the 'survey of Yorkshire dentists' targeted the dental foundation trainees. A mixed-method of quantitative and thematic content analysis was undertaken for the close-ended and free-text responses, respectively.Results Only 35% of participants described their confidence level as 'satisfactory' in placing dental amalgam before starting their dental foundation training and 51% scored the level of teaching between 'very poor' and 'satisfactory'. In total, 63% of respondents were in favour of receiving additional support in placing amalgam restorations during their undergraduate training. Participants indicated that the consequences of amalgam phase-out are increased appointment times and decreased quality of care due to patient and health service unaffordability of amalgam alternatives.Conclusion These findings raise concerns regarding newly qualified undergraduates' confidence, experience and skill in placing amalgams. This suggests the need to increase undergraduate education and training to improve undergraduates' skills and confidence in amalgam procedures to reduce the gap between the dental schools and real-world practice.
Topics: Humans; Dental Amalgam; Schools, Dental; Students; Dental Care
PubMed: 37684467
DOI: 10.1038/s41415-023-6228-4