In this study,different conditions of sandblasting on dental implant fixtures were investigated to achieve the best sandblasting conditions.18 different sandblasting conditions(Using 152 implant fixture samples)were e...In this study,different conditions of sandblasting on dental implant fixtures were investigated to achieve the best sandblasting conditions.18 different sandblasting conditions(Using 152 implant fixture samples)were examined,including parameters such as particle size,particle blasting pressure,and particle blasting angle.The surface treatment of the samples was performed using the SLA+Anodizing method.AFM testing was performed for each of the 18 different states,and the average surface roughness of each of these was compared with each other.Then,a bone layer was placed on the sample with the closest average surface roughness to the standard and the least amount of aluminum oxide on its surface among the 18 different states,to confirm the accuracy and quality of the desired surface roughness by examining the bone formation process and speed.The results showed that state No.4(sandblast particle size:75µm,spraying pressure of sandblast particles:4 bar,sandblast particle spraying angle:30 degrees),which was prepared using the SLA+Anodizing method and had a surface roughness of 1.989µm(The percentage of Al_(2)O_(3)on the surface=6%),had the best sandblasting conditions and showed 95%cell viability and accelerated the treatment and bone formation process for about a week.The simulation results,using Abaqus software,indicated that the stress distribution on the surface of the implant fixture in contact with the bone surface has increased by approximately 4.3%for state No.4.This will help prevent loosening of the dental implant fixture over time.展开更多
BACKGROUND: Dental anomalies are variations from the established well-known general anatomy and morphology of the tooth as a result of disturbances during tooth formation. They can be developmental, congenital, or acq...BACKGROUND: Dental anomalies are variations from the established well-known general anatomy and morphology of the tooth as a result of disturbances during tooth formation. They can be developmental, congenital, or acquired and may be localized to a single tooth or involve systemic conditions. AIM: To evaluate the prevalence of dental anomalies in patients who report to the Komfo Anokye Teaching Hospital (KATH) dental clinics. METHOD: A descriptive cross-sectional design was used with a sample size of 92 patients aged 18 or older, obtained through convenience sampling. Data analysis was performed using SPSS version 26.0. RESULTS: The study included 92 patients aged 18 to 72 years, with 47.8% males and 52.2% females. Dental anomalies were observed in 51.1% of participants, with a higher prevalence in females (55.3%). The most common anomalies were diastema (48.3%), impacted teeth (22.0%), dilaceration (11.9%), and peg-shaped lateral teeth (6.8%). CONCLUSION: This study highlights the importance of conducting thorough dental examinations to identify and address dental anomalies, which may have implications for treatment. Early detection and correction of these anomalies are crucial to prevent future complications.展开更多
Dental stem cells(DSCs)have attracted significant interest as autologous stem cells since they are easily accessible and give a minimal immune response.These properties and their ability to both maintain self-renewal ...Dental stem cells(DSCs)have attracted significant interest as autologous stem cells since they are easily accessible and give a minimal immune response.These properties and their ability to both maintain self-renewal and undergo multi-lineage differentiation establish them as key players in regenerative medicine.While many regulatory factors determine the differentiation trajectory of DSCs,prior research has predominantly been based on genetic,epigenetic,and molecular aspects.Recent evidence suggests that DSC differentiation can also be influenced by autophagy,a highly conserved cellular process responsible for maintaining cellular and tissue homeostasis under various stress conditions.This comprehensive review endeavors to elucidate the intricate regulatory mechanism and relationship between autophagy and DSC differentiation.To achieve this goal,we dissect the intricacies of autophagy and its mechanisms.Subsequently,we elucidate its pivotal roles in impacting DSC differentiation,including osteo/odontogenic,neurogenic,and angiogenic trajectories.Furthermore,we reveal the regulatory factors that govern autophagy in DSC lineage commitment,including scaffold materials,pharmaceutical cues,and the extrinsic milieu.The implications of this review are far-reaching,underpinning the potential to wield autophagy as a regulatory tool to expedite DSC-directed differentiation and thereby promote the application of DSCs within the realm of regenerative medicine.展开更多
Human dental pulp stem cell transplantation has been shown to be an effective therapeutic strategy for spinal cord injury.However,whether the human dental pulp stem cell secretome can contribute to functional recovery...Human dental pulp stem cell transplantation has been shown to be an effective therapeutic strategy for spinal cord injury.However,whether the human dental pulp stem cell secretome can contribute to functional recovery after spinal cord injury remains unclear.In the present study,we established a rat model of spinal cord injury based on impact injury from a dropped weight and then intraperitoneally injected the rats with conditioned medium from human dental pulp stem cells.We found that the conditioned medium effectively promoted the recovery of sensory and motor functions in rats with spinal cord injury,decreased expression of the microglial pyroptosis markers NLRP3,GSDMD,caspase-1,and interleukin-1β,promoted axonal and myelin regeneration,and inhibited the formation of glial scars.In addition,in a lipopolysaccharide-induced BV2 microglia model,conditioned medium from human dental pulp stem cells protected cells from pyroptosis by inhibiting the NLRP3/caspase-1/interleukin-1βpathway.These results indicate that conditioned medium from human dental pulp stem cells can reduce microglial pyroptosis by inhibiting the NLRP3/caspase-1/interleukin-1βpathway,thereby promoting the recovery of neurological function after spinal cord injury.Therefore,conditioned medium from human dental pulp stem cells may become an alternative therapy for spinal cord injury.展开更多
Dental pulp stem/stromal cells(DPSCs)are fibroblast-like,neural crest-derived,and multipotent cells that can differentiate into several lineages.They are relatively easy to isolate from healthy and inflamed pulps,with...Dental pulp stem/stromal cells(DPSCs)are fibroblast-like,neural crest-derived,and multipotent cells that can differentiate into several lineages.They are relatively easy to isolate from healthy and inflamed pulps,with little ethical concerns and can be successfully cryopreserved and thawed.The therapeutic effects of DPSCs derived from animal or human sources have been extensively studied through in-vitro and in-vivo animal experiments and the findings indicated that DPSCs are effective not only for dental diseases but also for systemic diseases.Understanding that translational research is a critical step through which the fundamental scientific discoveries could be translated into applicable diagnostics and therapeutics that directly benefit humans,several clinical studies were carried out to generate evidence for the efficacy and safety of autogenous or allogeneic human DPSCs(hDPSCs)as a treatment modality for use in cell-based therapy,regenerative medicine/dentistry and tissue engineering.In clinical medicine,hDPSCs were effective for treating acute ischemic stroke and human exfoliated deciduous teeth-conditioned medium(SHED-CM)repaired vascular damage of the corpus cavernous,which is the main cause of erectile dysfunction.Whereas in clinical dentistry,autologous SHED was able to rege-nerate necrotic dental pulp after implantation into injured teeth,and micrografts enriched with autologous hDPSCs and collagen sponge were considered a treatment option for human intrabony defects.In contrast,hDPSCs did not add a significant regenerative effect when they were used for the treatment of post-extraction sockets.Large-scale clinical studies across diverse populations are still lacking to provide robust evidence on the safety and efficacy of hDPSCs as a new treatment option for various human diseases including dental-related problems.展开更多
BACKGROUND The self-assembly of solid organs from stem cells has the potential to greatly expand the applicability of regenerative medicine.Stem cells can self-organise into microsized organ units,partially modelling ...BACKGROUND The self-assembly of solid organs from stem cells has the potential to greatly expand the applicability of regenerative medicine.Stem cells can self-organise into microsized organ units,partially modelling tissue function and regeneration.Dental pulp organoids have been used to recapitulate the processes of tooth development and related diseases.However,the lack of vasculature limits the utility of dental pulp organoids.AIM To improve survival and aid in recovery after stem cell transplantation,we demonstrated the three-dimensional(3D)self-assembly of adult stem cell-human dental pulp stem cells(hDPSCs)and endothelial cells(ECs)into a novel type of spheroid-shaped dental pulp organoid in vitro under hypoxia and conditioned medium(CM).METHODS During culture,primary hDPSCs were induced to differentiate into ECs by exposing them to a hypoxic environment and CM.The hypoxic pretreated hDPSCs were then mixed with ECs at specific ratios and conditioned in a 3D environment to produce prevascularized dental pulp organoids.The biological characteristics of the organoids were analysed,and the regulatory pathways associated with angiogenesis were studied.RESULTS The combination of these two agents resulted in prevascularized human dental pulp organoids(Vorganoids)that more closely resembled dental pulp tissue in terms of morphology and function.Single-cell RNA sequencing of dental pulp tissue and RNA sequencing of Vorganoids were integrated to analyse key regulatory pathways associated with angiogenesis.The biomarkers forkhead box protein O1 and fibroblast growth factor 2 were identified to be involved in the regulation of Vorganoids.CONCLUSION In this innovative study,we effectively established an in vitro model of Vorganoids and used it to elucidate new mechanisms of angiogenesis during regeneration,facilitating the development of clinical treatment strategies.展开更多
Background: Medical and dental students are at risk of Hepatitis B Virus (HBV) infection. The study aimed to assess the vaccination status against Hepatitis B Virus of students in clinical and non-clinical years of a ...Background: Medical and dental students are at risk of Hepatitis B Virus (HBV) infection. The study aimed to assess the vaccination status against Hepatitis B Virus of students in clinical and non-clinical years of a private medical and dental college, and their knowledge, attitude, and awareness about the subject. Methods: A cross-sectional study was conducted using a pretested, self-administered questionnaire among 203 medical and dental students of CMH Lahore Medical College and Institute of Dentistry (CMH LMC & IOD) in Lahore, Pakistan. Participants were evaluated for their knowledge and vaccination status against Hepatitis B Virus. Students were considered to be fully vaccinated (recipients of 3 doses), partially vaccinated (recipients of 1 or 2 doses), and unvaccinated. Comparisons were made between students of clinical and non-clinical years. Data was entered and analysed using Statistical Package for the Social Sciences (SPSS) version 23. Results: Only 66% (n = 134) of the 203 participants had ever received a Hepatitis B Virus vaccine out of which a meagre 17.2% (n = 35) were fully vaccinated. No significant difference was found in vaccine uptake between students of clinical and non-clinical years (p-value = 0.181) despite significant differences seen in the knowledge of vaccination schedule (p-value = 0.001), the prevalence of needle-stick injuries (p-value = 0.001), and knowledge of protocols to be followed after a needle-stick injury (p-value = 0.001). Conclusion: Our study found that a large proportion of the student population is vulnerable to HBV infection. There is a need to create awareness regarding the subject to increase vaccine uptake. HBV vaccination should be offered to all currently enrolled students and be made mandatory at the time of admission in the future.展开更多
Objective:To explore the relationships between the daily total intake of fluoride,dental fluorosis and dental caries. Methods: An epidemiological method was used to investigate the daily total intake of fluoride,denta...Objective:To explore the relationships between the daily total intake of fluoride,dental fluorosis and dental caries. Methods: An epidemiological method was used to investigate the daily total intake of fluoride,dental fluorosis,and dental caries among 236 and 290 children aged 8-13 years in a severe endemic area and in a non-fluorosis control area,respectively. The children were divided into eight subgroups according to each child’s estimated daily total intake of fluoride. The prevalence of dental fluorosis and dental caries in each group was calculated. Results: As expected,elevated levels of fluoride intake were significantly associated with a higher prevalence of dental fluorosis and an increasing amount of more severe defect dental fluorosis. When the daily total F intake was 2.78 mg/child/day,the prevalence of dental fluorosis was nearly 100%,with the prevalence of defect dental fluorosis increasing with increasing fluoride intake. There was also a significant negative(inverse) dose-response relationship between the daily total intake of fluoride and the overall preva-lence of dental caries,the prevalence of which decreased when the daily total intake of fluoride increased up to 3.32 mg/child/day. However,at higher levels of daily total intake of fluoride the prevalence of dental caries increased,giving rise to a U-shaped dose-response relationship curve. Conclusion: It is important to monitor total fluoride exposure and protect children from excessive fluoride intake,especially during the years of tooth development.展开更多
Medical Geology can be defined as the branch of geology dealing with the relationship between natural geological aspects and health in organisms (humans and animals), trying to determine the influence of ordinary envi...Medical Geology can be defined as the branch of geology dealing with the relationship between natural geological aspects and health in organisms (humans and animals), trying to determine the influence of ordinary environmental factors on the geographical distribution of health issues. The main goals of this research were: 1) to evaluate the severity of dental fluorosis (DF) and fluoride concentration in groundwater, used for human consumption, as an indicator of overexposure to fluorides, 2) to estimate the Community Fluorosis Index (CFI) in the Julimes municipality in Chihuahua, Mexico. Nine water samples were collected in four locations in the Julimes area: Hacienda Humboldt, La Regina, Colonia San Jose, and Julimes. Samples were collected and stored in accordance with the Mexican standard (NOM-014-SSA1-1993). All the samples exceeded the maximum permissible limit established in the modified Mexican standard (NOM-127-SSA1-1994) of 1.5 mgL<sup>-1</sup> for fluoride in water for human consumption. Average concentrations of 2.74 mgL<sup>-1</sup> were found in Colonia San Jose, 2.19 mgL<sup>-1</sup> in La Regina, 2.17 mgL<sup>-1</sup> in Julimes and 2.06 mgL<sup>-1</sup> in Hacienda Humboldt. Dental Fluorosis diagnosis was evaluated using the Dean Index and the CFI applied to residents. A total of 100 inhabitants were examined, with interviews and oral examinations also carried out. Dental Fluorosis prevalence was 92% overall for the municipality, while for Colonia San Jose was of 100%, of 88.89% for Hacienda Humboldt, 88.24% for Julimes and 96% for La Regina. Dental Fluorosis’ severity for the Julimes municipality was distributed as follows: 2% normal, 6% questionable, 8% very mild, 13% mild, 19% moderate, and 52% severe. An average CFI was found for the four localities of 3.02 points, with a very notable impact on public health.展开更多
The authors have presented a technique of full occlusal rehabilitation in a case of severe dental fluorosis. In this technique, maxillary and mandibular anterior teeth were simultaneously prepared and restored first. ...The authors have presented a technique of full occlusal rehabilitation in a case of severe dental fluorosis. In this technique, maxillary and mandibular anterior teeth were simultaneously prepared and restored first. This was followed by simultaneous preparation of maxillary and mandibular posterior teeth that were restored in canine guided occlusion. The technique and sequence followed here is unique and is not available in dental literature. This technique reduces number of appointments while fulfilling all objectives. Periodontal followup over 3 years was satisfactory. A restorative treatment protocol has been devised for fluorosis which will act as a guide for the dental practitioners.展开更多
Objectives: 1) To identify the hydrogeological characteristics and fluoride (F-) concentration in drinking water in the southeast of the state of Morelos, Mexico, and 2) to estimate the association between the prevale...Objectives: 1) To identify the hydrogeological characteristics and fluoride (F-) concentration in drinking water in the southeast of the state of Morelos, Mexico, and 2) to estimate the association between the prevalence and severity of fluorosis, dental caries, and water F-?concentration. Methods: A hydrogeological model was developed to determine the vertical distribution of lithostratigraphic units, rocks’ hydraulic conductivities, and groundwater flow characteristics. A total of 649 schoolchildren from two communities received oral examinations. One community was located in an area with 0.75 mg F-/L in the water supply and the other in an area with 1.6 mg F-/L. Fluorosis was assessed using the Thylstrup & Fejerskov Index (TFI) and the dental caries were assessed with the decayed, missing, and filled teeth (DMFT) index. The region groundwater was extracted from an inter-granular aquifer consisting of volcano clasts of intermediate volcanic chemical composition. Results: Oral examinations showed that 32.35% of the children had severe forms of fluorosis (TFI ≥ 4) in the community with 1.60 mg F-/L and 7.8% in the 0.75 mg F-/L community (p < 0.0001). DMFT = 0.53 (±1.28) and 0.42 (±0.95) in the community with 1.60 mg F-/L and 0.75 mg F-/L, respectively (p = 0.2259). Conclusions: The increasing extraction of underground water was associated with deeper water flows and higher F-?concentration. In the community with high F-concentration, a third of the children showed objectionable levels of fluorosis. Adequate groundwater management actions are required to reduce fluorosis risk.展开更多
For nearly 20 years,dental stem cells(DSCs)have been successfully isolated from mature/immature teeth and surrounding tissue,including dental pulp of permanent teeth and exfoliated deciduous teeth,periodontal ligament...For nearly 20 years,dental stem cells(DSCs)have been successfully isolated from mature/immature teeth and surrounding tissue,including dental pulp of permanent teeth and exfoliated deciduous teeth,periodontal ligaments,dental follicles,and gingival and apical papilla.They have several properties(such as self-renewal,multidirectional differentiation,and immunomodulation)and exhibit enormous potential for clinical applications.To date,many clinical articles and clinical trials using DSCs have reported the treatment of pulpitis,periapical lesions,periodontitis,cleft lip and palate,acute ischemic stroke,and so on,and DSC-based therapies obtained satisfactory effects in most clinical trials.In these studies,no adverse events were reported,which suggested the safety of DSC-based therapy.In this review,we outline the characteristics of DSCs and summ-arize clinical trials and their safety as DSC-based therapies.Meanwhile,we also present the current limitations and perspectives of DSC-based therapy(such as harvesting DSCs from inflamed tissue,applying DSC-conditioned medi-um/DSC-derived extracellular vesicles,and expanding-free strategies)to provide a theoretical basis for their clinical applications.展开更多
The community La Llave, Queretaro State, Mexico, has not been identified by the sanitary authorities as living in a hazard area related to dental fluorosis. However;a high concentration of fluoride is found in their d...The community La Llave, Queretaro State, Mexico, has not been identified by the sanitary authorities as living in a hazard area related to dental fluorosis. However;a high concentration of fluoride is found in their drinking water causing them dental fluorosis. Physical-chemical analysis was carried out in the groundwater sources to determine the prevalence of dental fluorosis risk and caries accordingly to criteria of The World Health Organization, and 154 school children of ages 10 to 13 years were examined. As a result, 1.9 mg/L of fluorine concentration in drinking water was obtained;dental fluorosis presence was detected in the school children with an incidence of about 98%, in 47% of cases severe fluorosis with a dental caries index of 3.06 was traced. The groundwater sources in La Llave community contains fluorine above the limits dictated by Mexican regulations, producing serious repercussions on the health of school children, with an unnaturally high incidence of dental fluorosis.展开更多
This study was conducted to assess the level of dental flourosis and Decaying, Missing, Filled Tooth (DMFT) of selected patients, in district Mardan village Rustam and District Mianwali village Harnoli. Study was cond...This study was conducted to assess the level of dental flourosis and Decaying, Missing, Filled Tooth (DMFT) of selected patients, in district Mardan village Rustam and District Mianwali village Harnoli. Study was conducted among people of age 10 - 60 years. The regions of Rustam and Harnoli are known to have high value of fluoride in drinking water. A cross sectional study was conducted among the subjects and the grade of fluorosis was calculated according to Deans Fluorosis Index. DMFT of each subject was also calculated. Total of 100 subjects were selected by simple random sampling technique among the population of Rustam and Harnoli and they were observed for the extent of fluorosis they had along with the number of decayed, missing and filled teeth they had Most of the population uses underground water, the water people commonly used was collected and was tested for amount of fluoride. The results show that there is a strong relationship between fluoride level and extent of fluorosis. Populations of both areas have dental fluorosis due to high concentration of fluoride in drinking water and also comparatively low DMFT because fluoride has caries protective effect.展开更多
Since dental pulp stem cells(DPSCs)were first reported,six types of dental SCs(DSCs)have been isolated and identified.DSCs originating from the craniofacial neural crest exhibit dental-like tissue differentiation pote...Since dental pulp stem cells(DPSCs)were first reported,six types of dental SCs(DSCs)have been isolated and identified.DSCs originating from the craniofacial neural crest exhibit dental-like tissue differentiation potential and neuroectodermal features.As a member of DSCs,dental follicle SCs(DFSCs)are the only cell type obtained at the early developing stage of the tooth prior to eruption.Dental follicle tissue has the distinct advantage of large tissue volume compared with other dental tissues,which is a prerequisite for obtaining a sufficient number of cells to meet the needs of clinical applications.Furthermore,DFSCs exhibit a significantly higher cell proliferation rate,higher colony-formation capacity,and more primitive and better anti-inflammatory effects than other DSCs.In this respect,DFSCs have the potential to be of great clinical significance and translational value in oral and neurological diseases,with natural advantages based on their origin.Lastly,cryopreservation preserves the biological properties of DFSCs and enables them to be used as off-shelf products for clinical applications.This review summarizes and comments on the properties,application potential,and clinical transformation value of DFSCs,thereby inspiring novel perspectives in the future treatment of oral and neurological diseases.展开更多
Human dental pulp stem cells(hDPSCs) promote recovery after ischemic stro ke;however,the therapeutic efficacy is limited by the poor survival of transplanted cells.For in vitro expe riments in the present study,we use...Human dental pulp stem cells(hDPSCs) promote recovery after ischemic stro ke;however,the therapeutic efficacy is limited by the poor survival of transplanted cells.For in vitro expe riments in the present study,we used oxygen-glucose deprivation/reoxygenation in hDPSCs to mimic cell damage induced by ischemia/reperfusion.We found that miRNA-34a-5p(miR-34a) was elevated under oxygen-glucose deprivation/reoxygenation conditions in hDPSCs.Inhibition of miR-34a facilitated the prolife ration and antioxidant capacity and reduced the apoptosis of hDPSCs.Moreove r,dual-luciferase reporter gene assay showed WNT1and SIRT1 as the targets of miR-34a.In miR-34a knockdown cell lines,WNT1 suppression reduced cell prolife ration,and SIRT1 suppression decreased the antioxidant capacity.Togethe r,these results indicated that miR-34a regulates cell prolife ration and antioxidant stress via targeting WNT1 and SIRT1,respectively.For in vivo expe riments,we injected genetically modified hDPSCs(anti34a-hDPSCs) into the brains of mice.We found that anti34a-hDPSCs significantly inhibited apoptosis,reduced cerebral edema and cerebral infarct volume,and improved motor function in mice.This study provides new insights into the molecular mechanism of the cell prolife ration and antioxidant capacity of hDPSCs,and suggests a potential gene that can be targeted to improve the survival rate and efficacy of transplanted hDPSCs in brain after ischemic stroke.展开更多
Objective: To assess the actual practical attitude and knowledge of dental implants among senior dental students and general dentists graduated from some Saudi and Non-Saudi dental schools. Methods: A total of 300 sen...Objective: To assess the actual practical attitude and knowledge of dental implants among senior dental students and general dentists graduated from some Saudi and Non-Saudi dental schools. Methods: A total of 300 senior dental students and general dentists participated in the study. Hard copies of the self-designed, multiple-choice questionnaires were distributed to all participants. The questionnaire consisted of 31 questions in five parts. Data were collected and analyzed using Chi-square test and t-test, where p Results: There is a statistically significant relationship between the participants’ answers, and their dental schools. Participants’ general knowledge, training, and teaching of dental implants, as well as information about restorations retained for the dental implants, were higher among participants from Saudi dental schools than participants from non-Saudi dental schools, while the information about dental implants was higher among participants from non-Saudi dental schools than participants from Saudi dental schools. Conclusion: We conclude that the actual practical attitude and knowledge of dental implants among participants in the current study was insufficient. Therefore, dental implant education in the undergraduate curricula of dental schools surveyed should be updated to include teaching, laboratory training, and preclinical and clinical training.展开更多
The main role of this article is to describe dental assistants and the dental department’s role in the dental delivery system for Special health care needs (SCHN) by creating a structure to educate the dental assisti...The main role of this article is to describe dental assistants and the dental department’s role in the dental delivery system for Special health care needs (SCHN) by creating a structure to educate the dental assisting profession and project factors that have a significant impact on the dental assistant. The dental assisting management of SCHN patient’s profession including dental Assistance general responsibilities, regulation credentialing, and education. The SCHN patient’s management creates a challenge in all area of the dental department. Handling patient with a SCHN is underexplored throughout the dental staff especially when there is not enough theoretical foundation, education and training to deal with this category of patients. SCHN patients are defined as individuals who have abnormal behavioral impairments, mental conditions or/and chronic disease or abnormal laboratory results. Thus, the aim of this article is to guide all dental assistance staff in the best dental management choice for SCHN patients. All health care teams are part of patient care in most medical settings. A work environment supportive ensures positive outcomes for patient care. This article was considered as those categories of patients required more care and special way to deal with, moreover language, age, gender and education level of the patient are also considered significant parries. Not Many studies were found to support the care of SCHN patients in dentistry department. Taking experience from other area help to design a system to handle the SCHN even if it requires hiring a Dentist who is specialized in that filed.展开更多
文摘In this study,different conditions of sandblasting on dental implant fixtures were investigated to achieve the best sandblasting conditions.18 different sandblasting conditions(Using 152 implant fixture samples)were examined,including parameters such as particle size,particle blasting pressure,and particle blasting angle.The surface treatment of the samples was performed using the SLA+Anodizing method.AFM testing was performed for each of the 18 different states,and the average surface roughness of each of these was compared with each other.Then,a bone layer was placed on the sample with the closest average surface roughness to the standard and the least amount of aluminum oxide on its surface among the 18 different states,to confirm the accuracy and quality of the desired surface roughness by examining the bone formation process and speed.The results showed that state No.4(sandblast particle size:75µm,spraying pressure of sandblast particles:4 bar,sandblast particle spraying angle:30 degrees),which was prepared using the SLA+Anodizing method and had a surface roughness of 1.989µm(The percentage of Al_(2)O_(3)on the surface=6%),had the best sandblasting conditions and showed 95%cell viability and accelerated the treatment and bone formation process for about a week.The simulation results,using Abaqus software,indicated that the stress distribution on the surface of the implant fixture in contact with the bone surface has increased by approximately 4.3%for state No.4.This will help prevent loosening of the dental implant fixture over time.
文摘BACKGROUND: Dental anomalies are variations from the established well-known general anatomy and morphology of the tooth as a result of disturbances during tooth formation. They can be developmental, congenital, or acquired and may be localized to a single tooth or involve systemic conditions. AIM: To evaluate the prevalence of dental anomalies in patients who report to the Komfo Anokye Teaching Hospital (KATH) dental clinics. METHOD: A descriptive cross-sectional design was used with a sample size of 92 patients aged 18 or older, obtained through convenience sampling. Data analysis was performed using SPSS version 26.0. RESULTS: The study included 92 patients aged 18 to 72 years, with 47.8% males and 52.2% females. Dental anomalies were observed in 51.1% of participants, with a higher prevalence in females (55.3%). The most common anomalies were diastema (48.3%), impacted teeth (22.0%), dilaceration (11.9%), and peg-shaped lateral teeth (6.8%). CONCLUSION: This study highlights the importance of conducting thorough dental examinations to identify and address dental anomalies, which may have implications for treatment. Early detection and correction of these anomalies are crucial to prevent future complications.
基金funded by grants from the National Natural Science Foundation of China(Nos.81771095,82071235)Key R&D Program of Shaanxi Province(2017SF-103,2021KWZ-26,2023-JC-ZD-56)State Key Laboratory of Military Stomatology(2020ZA01).
文摘Dental stem cells(DSCs)have attracted significant interest as autologous stem cells since they are easily accessible and give a minimal immune response.These properties and their ability to both maintain self-renewal and undergo multi-lineage differentiation establish them as key players in regenerative medicine.While many regulatory factors determine the differentiation trajectory of DSCs,prior research has predominantly been based on genetic,epigenetic,and molecular aspects.Recent evidence suggests that DSC differentiation can also be influenced by autophagy,a highly conserved cellular process responsible for maintaining cellular and tissue homeostasis under various stress conditions.This comprehensive review endeavors to elucidate the intricate regulatory mechanism and relationship between autophagy and DSC differentiation.To achieve this goal,we dissect the intricacies of autophagy and its mechanisms.Subsequently,we elucidate its pivotal roles in impacting DSC differentiation,including osteo/odontogenic,neurogenic,and angiogenic trajectories.Furthermore,we reveal the regulatory factors that govern autophagy in DSC lineage commitment,including scaffold materials,pharmaceutical cues,and the extrinsic milieu.The implications of this review are far-reaching,underpinning the potential to wield autophagy as a regulatory tool to expedite DSC-directed differentiation and thereby promote the application of DSCs within the realm of regenerative medicine.
基金supported by the Research Foundation of Technology Committee of Tongzhou District,No.KJ2019CX001(to SX).
文摘Human dental pulp stem cell transplantation has been shown to be an effective therapeutic strategy for spinal cord injury.However,whether the human dental pulp stem cell secretome can contribute to functional recovery after spinal cord injury remains unclear.In the present study,we established a rat model of spinal cord injury based on impact injury from a dropped weight and then intraperitoneally injected the rats with conditioned medium from human dental pulp stem cells.We found that the conditioned medium effectively promoted the recovery of sensory and motor functions in rats with spinal cord injury,decreased expression of the microglial pyroptosis markers NLRP3,GSDMD,caspase-1,and interleukin-1β,promoted axonal and myelin regeneration,and inhibited the formation of glial scars.In addition,in a lipopolysaccharide-induced BV2 microglia model,conditioned medium from human dental pulp stem cells protected cells from pyroptosis by inhibiting the NLRP3/caspase-1/interleukin-1βpathway.These results indicate that conditioned medium from human dental pulp stem cells can reduce microglial pyroptosis by inhibiting the NLRP3/caspase-1/interleukin-1βpathway,thereby promoting the recovery of neurological function after spinal cord injury.Therefore,conditioned medium from human dental pulp stem cells may become an alternative therapy for spinal cord injury.
文摘Dental pulp stem/stromal cells(DPSCs)are fibroblast-like,neural crest-derived,and multipotent cells that can differentiate into several lineages.They are relatively easy to isolate from healthy and inflamed pulps,with little ethical concerns and can be successfully cryopreserved and thawed.The therapeutic effects of DPSCs derived from animal or human sources have been extensively studied through in-vitro and in-vivo animal experiments and the findings indicated that DPSCs are effective not only for dental diseases but also for systemic diseases.Understanding that translational research is a critical step through which the fundamental scientific discoveries could be translated into applicable diagnostics and therapeutics that directly benefit humans,several clinical studies were carried out to generate evidence for the efficacy and safety of autogenous or allogeneic human DPSCs(hDPSCs)as a treatment modality for use in cell-based therapy,regenerative medicine/dentistry and tissue engineering.In clinical medicine,hDPSCs were effective for treating acute ischemic stroke and human exfoliated deciduous teeth-conditioned medium(SHED-CM)repaired vascular damage of the corpus cavernous,which is the main cause of erectile dysfunction.Whereas in clinical dentistry,autologous SHED was able to rege-nerate necrotic dental pulp after implantation into injured teeth,and micrografts enriched with autologous hDPSCs and collagen sponge were considered a treatment option for human intrabony defects.In contrast,hDPSCs did not add a significant regenerative effect when they were used for the treatment of post-extraction sockets.Large-scale clinical studies across diverse populations are still lacking to provide robust evidence on the safety and efficacy of hDPSCs as a new treatment option for various human diseases including dental-related problems.
基金Supported by the Science and Technology Programme of Guangzhou City,No.202201020341.
文摘BACKGROUND The self-assembly of solid organs from stem cells has the potential to greatly expand the applicability of regenerative medicine.Stem cells can self-organise into microsized organ units,partially modelling tissue function and regeneration.Dental pulp organoids have been used to recapitulate the processes of tooth development and related diseases.However,the lack of vasculature limits the utility of dental pulp organoids.AIM To improve survival and aid in recovery after stem cell transplantation,we demonstrated the three-dimensional(3D)self-assembly of adult stem cell-human dental pulp stem cells(hDPSCs)and endothelial cells(ECs)into a novel type of spheroid-shaped dental pulp organoid in vitro under hypoxia and conditioned medium(CM).METHODS During culture,primary hDPSCs were induced to differentiate into ECs by exposing them to a hypoxic environment and CM.The hypoxic pretreated hDPSCs were then mixed with ECs at specific ratios and conditioned in a 3D environment to produce prevascularized dental pulp organoids.The biological characteristics of the organoids were analysed,and the regulatory pathways associated with angiogenesis were studied.RESULTS The combination of these two agents resulted in prevascularized human dental pulp organoids(Vorganoids)that more closely resembled dental pulp tissue in terms of morphology and function.Single-cell RNA sequencing of dental pulp tissue and RNA sequencing of Vorganoids were integrated to analyse key regulatory pathways associated with angiogenesis.The biomarkers forkhead box protein O1 and fibroblast growth factor 2 were identified to be involved in the regulation of Vorganoids.CONCLUSION In this innovative study,we effectively established an in vitro model of Vorganoids and used it to elucidate new mechanisms of angiogenesis during regeneration,facilitating the development of clinical treatment strategies.
文摘Background: Medical and dental students are at risk of Hepatitis B Virus (HBV) infection. The study aimed to assess the vaccination status against Hepatitis B Virus of students in clinical and non-clinical years of a private medical and dental college, and their knowledge, attitude, and awareness about the subject. Methods: A cross-sectional study was conducted using a pretested, self-administered questionnaire among 203 medical and dental students of CMH Lahore Medical College and Institute of Dentistry (CMH LMC & IOD) in Lahore, Pakistan. Participants were evaluated for their knowledge and vaccination status against Hepatitis B Virus. Students were considered to be fully vaccinated (recipients of 3 doses), partially vaccinated (recipients of 1 or 2 doses), and unvaccinated. Comparisons were made between students of clinical and non-clinical years. Data was entered and analysed using Statistical Package for the Social Sciences (SPSS) version 23. Results: Only 66% (n = 134) of the 203 participants had ever received a Hepatitis B Virus vaccine out of which a meagre 17.2% (n = 35) were fully vaccinated. No significant difference was found in vaccine uptake between students of clinical and non-clinical years (p-value = 0.181) despite significant differences seen in the knowledge of vaccination schedule (p-value = 0.001), the prevalence of needle-stick injuries (p-value = 0.001), and knowledge of protocols to be followed after a needle-stick injury (p-value = 0.001). Conclusion: Our study found that a large proportion of the student population is vulnerable to HBV infection. There is a need to create awareness regarding the subject to increase vaccine uptake. HBV vaccination should be offered to all currently enrolled students and be made mandatory at the time of admission in the future.
基金supported by Jiangsu Provincial Foundation of Prevention Medicine(Y200621)
文摘Objective:To explore the relationships between the daily total intake of fluoride,dental fluorosis and dental caries. Methods: An epidemiological method was used to investigate the daily total intake of fluoride,dental fluorosis,and dental caries among 236 and 290 children aged 8-13 years in a severe endemic area and in a non-fluorosis control area,respectively. The children were divided into eight subgroups according to each child’s estimated daily total intake of fluoride. The prevalence of dental fluorosis and dental caries in each group was calculated. Results: As expected,elevated levels of fluoride intake were significantly associated with a higher prevalence of dental fluorosis and an increasing amount of more severe defect dental fluorosis. When the daily total F intake was 2.78 mg/child/day,the prevalence of dental fluorosis was nearly 100%,with the prevalence of defect dental fluorosis increasing with increasing fluoride intake. There was also a significant negative(inverse) dose-response relationship between the daily total intake of fluoride and the overall preva-lence of dental caries,the prevalence of which decreased when the daily total intake of fluoride increased up to 3.32 mg/child/day. However,at higher levels of daily total intake of fluoride the prevalence of dental caries increased,giving rise to a U-shaped dose-response relationship curve. Conclusion: It is important to monitor total fluoride exposure and protect children from excessive fluoride intake,especially during the years of tooth development.
文摘Medical Geology can be defined as the branch of geology dealing with the relationship between natural geological aspects and health in organisms (humans and animals), trying to determine the influence of ordinary environmental factors on the geographical distribution of health issues. The main goals of this research were: 1) to evaluate the severity of dental fluorosis (DF) and fluoride concentration in groundwater, used for human consumption, as an indicator of overexposure to fluorides, 2) to estimate the Community Fluorosis Index (CFI) in the Julimes municipality in Chihuahua, Mexico. Nine water samples were collected in four locations in the Julimes area: Hacienda Humboldt, La Regina, Colonia San Jose, and Julimes. Samples were collected and stored in accordance with the Mexican standard (NOM-014-SSA1-1993). All the samples exceeded the maximum permissible limit established in the modified Mexican standard (NOM-127-SSA1-1994) of 1.5 mgL<sup>-1</sup> for fluoride in water for human consumption. Average concentrations of 2.74 mgL<sup>-1</sup> were found in Colonia San Jose, 2.19 mgL<sup>-1</sup> in La Regina, 2.17 mgL<sup>-1</sup> in Julimes and 2.06 mgL<sup>-1</sup> in Hacienda Humboldt. Dental Fluorosis diagnosis was evaluated using the Dean Index and the CFI applied to residents. A total of 100 inhabitants were examined, with interviews and oral examinations also carried out. Dental Fluorosis prevalence was 92% overall for the municipality, while for Colonia San Jose was of 100%, of 88.89% for Hacienda Humboldt, 88.24% for Julimes and 96% for La Regina. Dental Fluorosis’ severity for the Julimes municipality was distributed as follows: 2% normal, 6% questionable, 8% very mild, 13% mild, 19% moderate, and 52% severe. An average CFI was found for the four localities of 3.02 points, with a very notable impact on public health.
文摘The authors have presented a technique of full occlusal rehabilitation in a case of severe dental fluorosis. In this technique, maxillary and mandibular anterior teeth were simultaneously prepared and restored first. This was followed by simultaneous preparation of maxillary and mandibular posterior teeth that were restored in canine guided occlusion. The technique and sequence followed here is unique and is not available in dental literature. This technique reduces number of appointments while fulfilling all objectives. Periodontal followup over 3 years was satisfactory. A restorative treatment protocol has been devised for fluorosis which will act as a guide for the dental practitioners.
文摘Objectives: 1) To identify the hydrogeological characteristics and fluoride (F-) concentration in drinking water in the southeast of the state of Morelos, Mexico, and 2) to estimate the association between the prevalence and severity of fluorosis, dental caries, and water F-?concentration. Methods: A hydrogeological model was developed to determine the vertical distribution of lithostratigraphic units, rocks’ hydraulic conductivities, and groundwater flow characteristics. A total of 649 schoolchildren from two communities received oral examinations. One community was located in an area with 0.75 mg F-/L in the water supply and the other in an area with 1.6 mg F-/L. Fluorosis was assessed using the Thylstrup & Fejerskov Index (TFI) and the dental caries were assessed with the decayed, missing, and filled teeth (DMFT) index. The region groundwater was extracted from an inter-granular aquifer consisting of volcano clasts of intermediate volcanic chemical composition. Results: Oral examinations showed that 32.35% of the children had severe forms of fluorosis (TFI ≥ 4) in the community with 1.60 mg F-/L and 7.8% in the 0.75 mg F-/L community (p < 0.0001). DMFT = 0.53 (±1.28) and 0.42 (±0.95) in the community with 1.60 mg F-/L and 0.75 mg F-/L, respectively (p = 0.2259). Conclusions: The increasing extraction of underground water was associated with deeper water flows and higher F-?concentration. In the community with high F-concentration, a third of the children showed objectionable levels of fluorosis. Adequate groundwater management actions are required to reduce fluorosis risk.
基金Supported by the National Natural Science Foundation of China,No.82071073 and No.82270951.
文摘For nearly 20 years,dental stem cells(DSCs)have been successfully isolated from mature/immature teeth and surrounding tissue,including dental pulp of permanent teeth and exfoliated deciduous teeth,periodontal ligaments,dental follicles,and gingival and apical papilla.They have several properties(such as self-renewal,multidirectional differentiation,and immunomodulation)and exhibit enormous potential for clinical applications.To date,many clinical articles and clinical trials using DSCs have reported the treatment of pulpitis,periapical lesions,periodontitis,cleft lip and palate,acute ischemic stroke,and so on,and DSC-based therapies obtained satisfactory effects in most clinical trials.In these studies,no adverse events were reported,which suggested the safety of DSC-based therapy.In this review,we outline the characteristics of DSCs and summ-arize clinical trials and their safety as DSC-based therapies.Meanwhile,we also present the current limitations and perspectives of DSC-based therapy(such as harvesting DSCs from inflamed tissue,applying DSC-conditioned medi-um/DSC-derived extracellular vesicles,and expanding-free strategies)to provide a theoretical basis for their clinical applications.
文摘The community La Llave, Queretaro State, Mexico, has not been identified by the sanitary authorities as living in a hazard area related to dental fluorosis. However;a high concentration of fluoride is found in their drinking water causing them dental fluorosis. Physical-chemical analysis was carried out in the groundwater sources to determine the prevalence of dental fluorosis risk and caries accordingly to criteria of The World Health Organization, and 154 school children of ages 10 to 13 years were examined. As a result, 1.9 mg/L of fluorine concentration in drinking water was obtained;dental fluorosis presence was detected in the school children with an incidence of about 98%, in 47% of cases severe fluorosis with a dental caries index of 3.06 was traced. The groundwater sources in La Llave community contains fluorine above the limits dictated by Mexican regulations, producing serious repercussions on the health of school children, with an unnaturally high incidence of dental fluorosis.
文摘This study was conducted to assess the level of dental flourosis and Decaying, Missing, Filled Tooth (DMFT) of selected patients, in district Mardan village Rustam and District Mianwali village Harnoli. Study was conducted among people of age 10 - 60 years. The regions of Rustam and Harnoli are known to have high value of fluoride in drinking water. A cross sectional study was conducted among the subjects and the grade of fluorosis was calculated according to Deans Fluorosis Index. DMFT of each subject was also calculated. Total of 100 subjects were selected by simple random sampling technique among the population of Rustam and Harnoli and they were observed for the extent of fluorosis they had along with the number of decayed, missing and filled teeth they had Most of the population uses underground water, the water people commonly used was collected and was tested for amount of fluoride. The results show that there is a strong relationship between fluoride level and extent of fluorosis. Populations of both areas have dental fluorosis due to high concentration of fluoride in drinking water and also comparatively low DMFT because fluoride has caries protective effect.
基金Supported by the Hainan Provincial Natural Science Foundation of China,No.822RC828.
文摘Since dental pulp stem cells(DPSCs)were first reported,six types of dental SCs(DSCs)have been isolated and identified.DSCs originating from the craniofacial neural crest exhibit dental-like tissue differentiation potential and neuroectodermal features.As a member of DSCs,dental follicle SCs(DFSCs)are the only cell type obtained at the early developing stage of the tooth prior to eruption.Dental follicle tissue has the distinct advantage of large tissue volume compared with other dental tissues,which is a prerequisite for obtaining a sufficient number of cells to meet the needs of clinical applications.Furthermore,DFSCs exhibit a significantly higher cell proliferation rate,higher colony-formation capacity,and more primitive and better anti-inflammatory effects than other DSCs.In this respect,DFSCs have the potential to be of great clinical significance and translational value in oral and neurological diseases,with natural advantages based on their origin.Lastly,cryopreservation preserves the biological properties of DFSCs and enables them to be used as off-shelf products for clinical applications.This review summarizes and comments on the properties,application potential,and clinical transformation value of DFSCs,thereby inspiring novel perspectives in the future treatment of oral and neurological diseases.
基金supported by the National Natural Science Foundation of China,Nos.81971870 and 82172173 (both to ML)。
文摘Human dental pulp stem cells(hDPSCs) promote recovery after ischemic stro ke;however,the therapeutic efficacy is limited by the poor survival of transplanted cells.For in vitro expe riments in the present study,we used oxygen-glucose deprivation/reoxygenation in hDPSCs to mimic cell damage induced by ischemia/reperfusion.We found that miRNA-34a-5p(miR-34a) was elevated under oxygen-glucose deprivation/reoxygenation conditions in hDPSCs.Inhibition of miR-34a facilitated the prolife ration and antioxidant capacity and reduced the apoptosis of hDPSCs.Moreove r,dual-luciferase reporter gene assay showed WNT1and SIRT1 as the targets of miR-34a.In miR-34a knockdown cell lines,WNT1 suppression reduced cell prolife ration,and SIRT1 suppression decreased the antioxidant capacity.Togethe r,these results indicated that miR-34a regulates cell prolife ration and antioxidant stress via targeting WNT1 and SIRT1,respectively.For in vivo expe riments,we injected genetically modified hDPSCs(anti34a-hDPSCs) into the brains of mice.We found that anti34a-hDPSCs significantly inhibited apoptosis,reduced cerebral edema and cerebral infarct volume,and improved motor function in mice.This study provides new insights into the molecular mechanism of the cell prolife ration and antioxidant capacity of hDPSCs,and suggests a potential gene that can be targeted to improve the survival rate and efficacy of transplanted hDPSCs in brain after ischemic stroke.
文摘Objective: To assess the actual practical attitude and knowledge of dental implants among senior dental students and general dentists graduated from some Saudi and Non-Saudi dental schools. Methods: A total of 300 senior dental students and general dentists participated in the study. Hard copies of the self-designed, multiple-choice questionnaires were distributed to all participants. The questionnaire consisted of 31 questions in five parts. Data were collected and analyzed using Chi-square test and t-test, where p Results: There is a statistically significant relationship between the participants’ answers, and their dental schools. Participants’ general knowledge, training, and teaching of dental implants, as well as information about restorations retained for the dental implants, were higher among participants from Saudi dental schools than participants from non-Saudi dental schools, while the information about dental implants was higher among participants from non-Saudi dental schools than participants from Saudi dental schools. Conclusion: We conclude that the actual practical attitude and knowledge of dental implants among participants in the current study was insufficient. Therefore, dental implant education in the undergraduate curricula of dental schools surveyed should be updated to include teaching, laboratory training, and preclinical and clinical training.
文摘The main role of this article is to describe dental assistants and the dental department’s role in the dental delivery system for Special health care needs (SCHN) by creating a structure to educate the dental assisting profession and project factors that have a significant impact on the dental assistant. The dental assisting management of SCHN patient’s profession including dental Assistance general responsibilities, regulation credentialing, and education. The SCHN patient’s management creates a challenge in all area of the dental department. Handling patient with a SCHN is underexplored throughout the dental staff especially when there is not enough theoretical foundation, education and training to deal with this category of patients. SCHN patients are defined as individuals who have abnormal behavioral impairments, mental conditions or/and chronic disease or abnormal laboratory results. Thus, the aim of this article is to guide all dental assistance staff in the best dental management choice for SCHN patients. All health care teams are part of patient care in most medical settings. A work environment supportive ensures positive outcomes for patient care. This article was considered as those categories of patients required more care and special way to deal with, moreover language, age, gender and education level of the patient are also considered significant parries. Not Many studies were found to support the care of SCHN patients in dentistry department. Taking experience from other area help to design a system to handle the SCHN even if it requires hiring a Dentist who is specialized in that filed.
