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Nigerian Journal of Clinical Practice Jun 2024Apically extruded debris can be affected by some features of the file systems such as kinematics or metallurgic properties.
BACKGROUND
Apically extruded debris can be affected by some features of the file systems such as kinematics or metallurgic properties.
AIMS
This in vitro study aimed to evaluate the effect of movement kinematics (reciprocation or rotation) and heat-treated alloys (C.Wire) on the amount of debris extrusion.
METHODS
Seventy-two mesiobuccal root canals were assigned into three experimental groups related to the single-file system used (n = 24): two rotational; One Shape (Conventional Ni-Ti), One Curve (C.Wire), and one reciprocating; and One Reci (C.Wire). The file systems were used according to the advisable speed and torque according to the manufacturers' suggestion. The weight of debris was calculated by subtracting the preweights from postweights of Eppendorf tubes. Kruskall-Wallis and Mann-Whitney U tests were used to analyze the data (P = 0.05).
RESULTS
One Shape produced the greatest amount of extruded debris compared with One Curve (P < 0.001) and One Reci (P < 0.001), respectively. No statistical difference was found between One Curve and One Reci concerning amount of apical debris extrusion (P = 0.489).
CONCLUSION
Metallurgical properties of files may affect apical debris extrusion. Alloy type is an important factor in the amount of debris extrusion. File kinematics does not affect apical debris extrusion.
Topics: Humans; Alloys; Root Canal Preparation; Hot Temperature; Biomechanical Phenomena; In Vitro Techniques; Materials Testing; Equipment Design; Nickel; Dental Pulp Cavity
PubMed: 38943303
DOI: 10.4103/njcp.njcp_889_23 -
Science Advances Jun 2024Rotator cuff repair surgeries fail frequently, with 20 to 94% of the 600,000 repairs performed annually in the United States resulting in retearing of the rotator cuff....
Rotator cuff repair surgeries fail frequently, with 20 to 94% of the 600,000 repairs performed annually in the United States resulting in retearing of the rotator cuff. The most common cause of failure is sutures tearing through tendons at grasping points. To address this issue, we drew inspiration from the specialized teeth of snakes of the Pythonoidea superfamily, which grasp soft tissues without tearing. To apply this nondamaging gripping approach to the surgical repair of tendon, we developed and optimized a python tooth-inspired device as an adjunct to current rotator cuff suture repair and found that it nearly doubled repair strength. Integrated simulations, 3D printing, and ex vivo experiments revealed a relationship between tooth shape and grasping mechanics, enabling optimization of the clinically relevant device that substantially enhances rotator cuff repair by distributing stresses over the attachment footprint. This approach suggests an alternative to traditional suturing paradigms and may reduce the risk of tendon retearing after rotator cuff repair.
Topics: Animals; Rotator Cuff; Boidae; Rotator Cuff Injuries; Tooth; Suture Techniques; Biomechanical Phenomena; Humans; Printing, Three-Dimensional
PubMed: 38941456
DOI: 10.1126/sciadv.adl5270 -
Frontiers in Bioscience (Landmark... Jun 2024Dental pulp stem cells (DPSCs) have self-renewal and multidirectional differentiation potentials. As such, DPSCs have a wide range of clinical applications. Low-level...
BACKGROUND
Dental pulp stem cells (DPSCs) have self-renewal and multidirectional differentiation potentials. As such, DPSCs have a wide range of clinical applications. Low-level laser therapy (LLLT) has positive photobiostimulatory effects on cell proliferation, angiogenesis, osteogenic differentiation, bone regeneration, and fracture healing. However, there have been few studies on the effect of low-energy lasers on DPSC proliferation.
METHODS
DPSCs were obtained from dental pulp tissue. The effects of LLLT on the proliferation of DPSCs and the associated mechanisms were investigated by culture and laser irradiation.
RESULTS
LLLT with energy densities of 3.5 J/cm2 and 14 J/cm2promoted the proliferation of DPSCs. Differential protein expression studies suggested the stimulation of DPSC proliferation by LLLT involved the PI3K-Akt and Rap1 signaling pathways, as well as the apoptosis-related pathway.
CONCLUSION
This preliminary study demonstrated that low-energy lasers have a pro-proliferative effect on DPSCs, and identified possible associated mechanisms. Our findings provide a theoretical basis for the clinical application of DPSCs and suggest novel strategies for the treatment of related diseases.
Topics: Dental Pulp; Cell Proliferation; Humans; Stem Cells; Low-Level Light Therapy; Cells, Cultured; Signal Transduction; Apoptosis; Cell Differentiation
PubMed: 38940041
DOI: 10.31083/j.fbl2906211 -
Frontiers in Cellular and Infection... 2024Recent studies have demonstrated a positive role of hyaluronic acid (HA) on periodontal clinical outcomes. This study aimed to investigate the impact of four different...
INTRODUCTION
Recent studies have demonstrated a positive role of hyaluronic acid (HA) on periodontal clinical outcomes. This study aimed to investigate the impact of four different HAs on interactions between periodontal biofilm and immune cells.
METHODS
The four HAs included: high-molecular-weight HA (HHA, non-cross-linked), low-molecular-weight HA (LHA), oligomers HA (OHA), and cross-linked high-molecular-weight HA (CHA). Serial experiments were conducted to verify the influence of HAs on: (i) 12-species periodontal biofilm (formation and pre-existing); (ii) expression of inflammatory cytokines and HA receptors in monocytic (MONO-MAC-6) cells and periodontal ligament fibroblasts (PDLF) with or without exposure to periodontal biofilms; (iii) generation of reactive oxygen species (ROS) in MONO-MAC-6 cells and PDLF with presence of biofilm and HA.
RESULTS
The results indicated that HHA and CHA reduced the bacterial counts in a newly formed (4-h) biofilm and in a pre-existing five-day-old biofilm. Without biofilm challenge, OHA triggered inflammatory reaction by increasing IL-1β and IL-10 levels in MONO-MAC cells and IL-8 in PDLF in a time-dependent manner, whereas CHA suppressed this response by inhibiting the expression of IL-10 in MONO-MAC cells and IL-8 in PDLF. Under biofilm challenge, HA decreased the expression of IL-1β (most decreasing HHA) and increased IL-10 levels in MONO-MAC-6 cells in a molecular weight dependent manner (most increasing CHA). The interaction between HA and both cells may occur via ICAM-1 receptor. Biofilm stimulus increased ROS levels in MONO-MAC-6 cells and PDLF, but only HHA slightly suppressed the high generation of ROS induced by biofilm stimulation in both cells.
CONCLUSION
Overall, these results indicate that OHA induces inflammation, while HHA and CHA exhibit anti-biofilm, primarily anti-inflammatory, and antioxidant properties in the periodontal environment.
Topics: Biofilms; Hyaluronic Acid; Humans; Reactive Oxygen Species; Fibroblasts; Cytokines; Monocytes; Periodontal Ligament; Cell Line; Interleukin-1beta; Interleukin-10
PubMed: 38938883
DOI: 10.3389/fcimb.2024.1414861 -
BMC Oral Health Jun 2024To examine the patterns of pretreatment facial soft tissue shape in orthodontic cases with premolar extraction using artificial intelligence (AI) and to investigate the... (Comparative Study)
Comparative Study
OBJECTIVE
To examine the patterns of pretreatment facial soft tissue shape in orthodontic cases with premolar extraction using artificial intelligence (AI) and to investigate the corresponding changes.
METHODS
One hundred and fifty-two patients who underwent orthodontic treatment with premolar extraction were enrolled. Lateral cephalograms were obtained before and after the treatment. For each record, the outlines of the nose-lip-chin profile and corresponding 21 cephalometric variables were extracted. The AI method classified pretreatment records into three subject groups based on the feature variables extracted from the outline. Dentoskeletal and soft tissue facial form changes observed after treatment were compared statistically (P < 0.05) between the groups using ANOVA. Multivariate regression models were used for each group.
RESULTS
Group 1 (n = 59) was characterized by Class II high-angle retrognathic mandible with an incompetent lip, group 2 (n = 55) by Class I malocclusion with retruded and thin lips, and group 3 (n = 38) by Class I malocclusion with an everted superior lip before treatment. The ratios of anteroposterior soft tissue to hard tissue movements in Group 1 were 56% (r = 0.64) and 83% (r = 0.75) for the superior and inferior lips, respectively, whereas those in Group 2 were 49% (r = 0.78) and 91% (r = 0.80), and 40% (r = 0.54) and 79% (r = 0.70), respectively, in Group 3.
CONCLUSIONS
The modes of facial form changes differed depending on the pre-treatment profile patterns classified by the AI. This indicates that the determination of the pre-treatment profile pattern can help in the selection of soft tissue to hard tissue movement ratios, which helps estimate the post-treatment facial profile with a moderate to high correlation.
Topics: Humans; Cephalometry; Face; Bicuspid; Tooth Extraction; Female; Male; Lip; Adolescent; Nose; Malocclusion, Angle Class I; Artificial Intelligence; Chin; Malocclusion, Angle Class II; Mandible; Tooth Movement Techniques; Child; Young Adult; Malocclusion
PubMed: 38937790
DOI: 10.1186/s12903-024-04512-2 -
BMC Oral Health Jun 2024The desirable properties of silver diamine fluoride (SDF) make it an effective agent for managing dental caries and tooth hypersensitivity. There are several clinical...
BACKGROUND
The desirable properties of silver diamine fluoride (SDF) make it an effective agent for managing dental caries and tooth hypersensitivity. There are several clinical instances that SDF application might precede the placement of direct tooth-colored restorations. On the other hand, SDF stains demineralized/carious dental tissues black, which might affect the esthetic outcomes of such restorations. Color is a key parameter of esthetics in dentistry. Therefore, this study aims to systematically review dental literature on color/color change of tooth-colored restorations placed following the application of SDF on dentine.
METHODS
Comprehensive search of PubMed, Embase, Scopus and ISI Web of Science databases (until August 2023) as well as reference lists of retrieved studies was performed. In vitro studies reported color or color change of tooth-colored restorative materials applied on SDF-treated dentine were included. Methodological quality assessment was performed using RoBDEMAT tool. Pooled weighted mean difference (WMD) and 95% confidence interval (95% CI) was calculated.
RESULTS
Eleven studies/reports with a total of 394 tooth-colored restorations placed following a) no SDF (control) or b) SDF with/without potassium iodide (KI)/glutathione dentine pre-treatments were included. Color change was quantified using ∆E formulas in most reports. The pooled findings for the comparison of resin-based composite (RBC) restorations with and without prior 38% SDF + KI application revealed no statistically significant differences in ∆E values at short- and long-term evaluations (~ 14 days: WMD: -0.56, 95% CI: -2.09 to 0.96; I: 89.6%, and ~ 60 days: WMD: 0.11; 95% CI: -1.51 to 1.72; I: 76.9%). No studies provided sufficient information for all the items in the risk of bias tool (moderate to low quality).
CONCLUSIONS
The limited evidence suggested comparable color changes of RBC restorations with and without 38% SDF + KI pre-treatment up to 60 days. The included studies lacked uniformity in methodology and reported outcomes. Further studies are imperative to draw more definite conclusions.
PROTOCOL REGISTRATION
The protocol of this systematic review was registered in PROSPERO database under number CRD42023485083.
Topics: Silver Compounds; Humans; Quaternary Ammonium Compounds; Fluorides, Topical; Dentin; Color; Dental Restoration, Permanent
PubMed: 38937760
DOI: 10.1186/s12903-024-04487-0 -
PloS One 2024The patterning cascade model of crown morphogenesis has been studied extensively in a variety of organisms to elucidate the evolutionary history surrounding postcanine...
OBJECTIVE
The patterning cascade model of crown morphogenesis has been studied extensively in a variety of organisms to elucidate the evolutionary history surrounding postcanine tooth form. The current research is the first to use a large modern human sample to examine whether the crown configuration of lower deciduous and permanent molars aligns with expectations derived from the model. This study has two main goals: 1) to determine if metameric and antimeric pairs significantly differ in size, accessory trait expression, and relative intercusp spacing, and 2) assess whether the relative distance among early-forming cusps accounts for observed variation in accessory cusp expression.
METHODS
Tooth size, intercusp distance, and morphological trait expression data were collected from 3D scans of mandibular dental casts representing participants of the Harvard Solomon Islands Project. Paired tests were utilized to compare tooth size, accessory trait expression, and relative intercusp distance between diphyodont metameres and permanent antimeres. Proportional odds logistic regression was implemented to investigate how the odds of greater accessory cusp expression vary as a function of the distance between early-developing cusps.
RESULTS/SIGNIFICANCE
Comparing paired molars, significant differences were identified for tooth size and cusp 5 expression. Several relative intercusp distances emerged as important predictors of cusp 6 expression, however, results for cusp 5 and cusp 7 did not match expected patterns. These findings support previous quantitative genetic results and suggest the development of neighboring crown structures represents a zero-sum partitioning of cellular territory and resources. As such, this study contributes to a better understanding of the foundations of deciduous and permanent molar crown variation in humans.
Topics: Humans; Tooth Crown; Molar; Dentition, Permanent; Morphogenesis; Tooth, Deciduous; Odontogenesis; Male; Child; Female
PubMed: 38935640
DOI: 10.1371/journal.pone.0304455 -
International Journal of Implant... Jun 2024This propensity score matching, multicenter, cross-sectional study was performed to examine the effects of various prosthetic methods for dental clinic outpatients with...
Effects of various prosthetic methods for patients with Kennedy Class I partial edentulism on oral hypofunction, subjective symptoms, and oral health-related quality of life.
PURPOSE
This propensity score matching, multicenter, cross-sectional study was performed to examine the effects of various prosthetic methods for dental clinic outpatients with Kennedy Class I partial edentulism (KCIPE) on oral hypofunction, subjective frailty symptoms, and oral health-related quality of life (QOL).
METHODS
Patients (n = 348) were classified into the following three groups for analysis: NT, patients with natural dentition providing intermaxillary contact in four occlusal supporting zones; RPD, patients with KCIPE who received removable partial dentures; and ISFP, patients with KCIPE who received implant-supported fixed prostheses. Participants' basic characteristics were recorded, and oral function tests were conducted. Subjective symptoms of physical and oral frailty were investigated via questionnaire. Oral health-related QOL was assessed using the Japanese short version of the Oral Health Impact Profile (OHIP-JP16). Propensity score matching was performed to adjust for patient background factors that could influence oral hypofunction in each group.
RESULTS
Compared with the ISFP group, the RPD group had significantly higher rates of poor oral hygiene, reduced occlusal force, decreased masticatory function, and declines in swallowing function and oral hypofunction; the odds ratio for oral hypofunction was 4.67. Compared with the ISFP group, the RPD group had significantly greater subjective symptoms of physical frailty and oral frailty, as well as higher OHIP scores.
CONCLUSIONS
Prosthetic treatment of KCIPE affected oral hypofunction, subjective frailty symptoms, and oral health-related QOL in dental clinic outpatients.
Topics: Humans; Quality of Life; Cross-Sectional Studies; Male; Female; Middle Aged; Oral Health; Jaw, Edentulous, Partially; Denture, Partial, Removable; Aged; Surveys and Questionnaires; Propensity Score; Dental Prosthesis, Implant-Supported; Denture, Partial, Fixed; Adult
PubMed: 38935335
DOI: 10.1186/s40729-024-00555-w -
Indian Journal of Dental Research :... Jan 2024During orthodontic treatment, temporary anchoring devices (TADs) are used to restrain tooth movement. They are a relatively recent addition to the dental toolkit.
INTRODUCTION
During orthodontic treatment, temporary anchoring devices (TADs) are used to restrain tooth movement. They are a relatively recent addition to the dental toolkit.
AIM
As TADs have limitations, Dr. Eric Lieu of Taiwan developed Infra Zygomatic Crest (IZC) screws which are placed between the maxillary second premolar at the bony crest.
TREATMENT PLANNING
The goal of this case study is to emphasize the value of anatomy, site selection, and IZC retrieval in the event of an accident. Cone beam computed tomography was used as a diagnostic tool for the precise location of the displaced IZC and immediate surgical retrieval was done under local anesthesia from the infratemporal space to prevent further complications.
TAKEAWAY LESSONS
Orthodontists knowledge of soft tissue and hard tissue anatomy and precise positioning is crucial for successful TAD implantation.
Topics: Humans; Orthodontic Anchorage Procedures; Cone-Beam Computed Tomography; Zygoma; Bone Screws; Male; Female; Bicuspid; Maxilla; Tooth Movement Techniques
PubMed: 38934757
DOI: 10.4103/ijdr.ijdr_143_23 -
Indian Journal of Dental Research :... Jan 2024Dental caries is a dynamic process. By using therapeutic agents, early, noncavitated lesions and caries limited to the enamel can be stopped or even remineralized. For... (Observational Study)
Observational Study
BACKGROUND
Dental caries is a dynamic process. By using therapeutic agents, early, noncavitated lesions and caries limited to the enamel can be stopped or even remineralized. For the remineralization of the initial carious lesion, many nonfluoridated remineralizing agents were investigated.
OBJECTIVES
An observational study to assess the remineralizing efficacy of tricalcium phosphate (TCP), nano-hydroxyapatite (nHAp) and ozone remineralizing agents on the artificial carious lesion.
METHODOLOGY
In this observational research, the artificial carious lesion was produced on extracted 40 premolar teeth. Later, remineralizing agents (Group A: nHAp, Group B: TCP, Group C: Ozone remineralizing agents, Group D: Control group (Deionized water) were used to remineralize demineralized teeth. Utilizing the Vickers Hardness Number, the level of demineralization and remineralization was assessed. Later these readings were statistically assessed using the Tukey's HSD (honestly significant difference) and ANOVA tests in SPSS version 21.0. The P value was set at 0.05 or less.
RESULTS
After demineralization, there was a decrease in enamel microhardness values, with 32% in Group A, 26% in Group B, 22% in Group C, and 21% in Group D, respectively. From the baseline to demineralization, there was a statistically significant decrease in microhardness across all groups. After remineralization, Groups A, B, and C experienced an increase in microhardness while Group D experienced no changes. This showed that Group A had the highest remineralization percentage, followed by Group B and Group C.
CONCLUSION
nHAp and TCP had the greater remineralizing ability, which can be used to manage initial carious lesions.
Topics: Calcium Phosphates; Tooth Remineralization; Durapatite; Dental Caries; Humans; Ozone; In Vitro Techniques; Cariostatic Agents; Bicuspid; Dental Enamel
PubMed: 38934756
DOI: 10.4103/ijdr.ijdr_704_22