Current Issue : April - June Volume : 2017 Issue Number : 2 Articles : 7 Articles
The objective of this study was to investigate if a prolonged bleaching effect of carbamide\nperoxide-loaded hollow calcium phosphate spheres (HCPS) can be achieved. HCPS was synthesized\nvia a hydrothermal reaction method. Carbamide peroxide (CP) was-loaded into HCPS by mixing\nwith distilled water as solvent. We developed two bleaching gels containing CP-loaded HCPS: one\ngel with low HP concentration as at-home bleaching gel, and one with high HP concentration as\nin-office gel. Their bleaching effects on stained human permanent posterior teeth were investigated\nby measuring the color difference before and after bleaching. The effect of gels on rhodamine B\ndegradation was also studied. To investigate the potential effect of remineralization of using HCPS,\nbleached teeth were soaked in phosphate buffer solution (PBS) containing calcium and magnesium\nions. Both bleaching gels had a prolonged whitening effect, and showed a strong ability to degrade\nrhodamine B. After soaking in PBS for 3 days, remineralization was observed at the sites where HCPS\nattached to the teeth surface. CP-loaded HCPS could prolong the HP release behavior and improve\nthe bleaching effect. HCPS was effective in increasing the whitening effect of carbamide peroxide\nand improving remineralization after bleaching process....
The accurate duplicate cast obtained froma single impression reduces the profession clinical time, patient inconvenience, and extra\nmaterial cost. The stainless steel working cast model assembly consisting of two abutments and one pontic area was fabricated. Two\nsets of six each customaluminumtrayswere fabricated, with fivemmspacer and twommspacer.The impressionmethods evaluated\nduring the study were additional silicone putty reline (two steps), heavy-light body (one step), monophase (one step), and polyether\n(one step). Type IV gypsum casts were poured at the interval of one hour, 12 hours, 24 hours, and 48 hours. The resultant cast was\nmeasured with traveling microscope for the comparative dimensional accuracy. The data obtained were subjected to Analysis of\nVariance test at significance level <0.05. The die obtained from two-step putty reline impression techniques had the percentage of\nvariation for the height âË?â??0.36 to âË?â??0.97%, while diameter was increased by 0.40ââ?¬â??0.90%. The values for one-step heavy-light body\nimpression dies, additional silicone monophase impressions, and polyether were âË?â??0.73 to âË?â??1.21%, âË?â??1.34%, and âË?â??1.46% for the height\nand 0.50ââ?¬â??0.80%, 1.20%, and âË?â??1.30% for the width, respectively....
Background: Malocclusion is a common disease of oral and maxillofacial region. The study was aimed to\ninvestigate levels changes of periodontal pathogens in malocclusion patients before, during and after orthodontic\ntreatments, and to confirm the difference between adults and children.\nMethod: One hundred and eight malocclusion patients (46 adults and 62 children at the school-age) were\nrandomly selected and received orthodontic treatment with fixed orthodontic appliances. Subgingival plaques were\nPorphyromonas gingivalis (P.gingivalis), Fusobacterium nucleatum (F. nucleatum), Prevotella intermedia (P. intermedia)\nand Tannerella forsythensis (T. forsythensis) collected from the observed regions before and after treatment. Clinical\nindexes, including plaque index (PLI), gingival index (GI), sulcus bleeding index (SBI), probing depth (PD) and\nattachment loss (AL) of observed teeth were examined.\nResults: The detection rates of P.gingivalis, F. nucleatum, P. intermedia and T. forsythensis increased from baseline to\nthe third month without significant difference, and then returned to pretreatment levels 12 month after applying\nfixed orthodontic appliances. Adults� percentage contents of P.gingivalis, F. nucleatum, P. intermedia and T.\nforsythensis were significantly higher than those of children at baseline and the first month, but not obvious at the\nthird month. PLI and SBI were increased from baseline to the first and to the third month both in adults and\nchildren groups. Besides, PD were increased from baseline to first month, followed by a downward trend in the\nthird month; however, all patients were failed to detect with AL.\nConclusions: Periodontal and microbiological statuses of malocclusion patients may be influenced by fixed\northodontic appliances in both adults and children, more significant in children than in adults. Some\nmicrobiological indexes have synchronous trend with the clinical indexes. Long-term efficacy of fixed orthodontic\nappliances for malocclusion should be confirmed by future researches....
This study investigated the effect of the oxygen-inhibited layer on the degree of conversion\n(DC) of three dental adhesives, comparing two different protocols. Quartzââ?¬â??tungstenââ?¬â??halogen\n(QTH) light curing and light-emitting diode (LED) were used to cure three adhesives: OptiBond\nAll in One (OAIO), Adper Easy Bond (AEB) and ExciteF (EXF). The DC was calculated utilizing\nFourier Transform infrared spectroscopy (FTIR) (n = 12). The two protocols used were as follows:\n(i) prevent the oxygen-inhibited layer using a Mylar plastic strip pushed onto each bonding adhesive;\nand (ii) polymerize samples without a plastic strip. The data was analyzed statistically by a three-way\nANOVA, and Tukey Test (a = 0.05). The presence of an oxygen-inhibited layer reduced the DC of\nthe adhesives by 64% for EXF, 46% for AEB and 32% for OAIO. This study suggests that there are\ndifferences among the oxygen-inhibited layers present for the adhesives tested....
Background: Periodontally accelerated osteogenic orthodontics (PAOO) combines periodontal therapy with\northodontic therapy, which minimises treatment time. This study compared the effectiveness of a bovine-derived\nxenograft with that of bioactive glass when combined with PAOO for the treatment of adult patients with\nmoderate crowding of the teeth.\nMethods: In this prospective, single-masked clinical trial, 33 orthodontic patients (20 women, 13 men; mean age\n21.2 Ã?± 1.43 [18 âË?â?? 27] years), were randomly allocated to one of three groups. Group 1 underwent a modified\ncorticotomy technique on the labial side only, whereas group 2 was treated with the same technique combined\nwith PAOO using a bovine-derived xenograft and group 3 was treated in the same way but combining PAOO with\nbioactive glass. The total treatment duration was recorded from the start of active orthodontic treatment,\nimmediately after corticotomy, and at the time of debonding. Probing depth was evaluated clinically and bone\ndensity and root length were evaluated radiographically on the day of surgery (baseline, T1), post-treatment at\ndebonding (T2), and 9 months post-treatment (T3).\nResults: The duration of orthodontic treatment was markedly reduced to an average of 11.4 Ã?± 0.14 weeks in all\ngroups. All probing depths were < 3 mm, the interdental papillae were well preserved, there was no loss of tooth\nvitality, and there was no evidence of significant apical root resorption at any time interval. All groups showed a\ndecrease in mean bone density at T2 followed by an increase at T3. The net percentage change that occurred\nbetween baseline and 9 months post-treatment was significantly different between the three groups. Groups 2 and\n3, where grafts were incorporated, demonstrated a statistically significant greater increase in bone density than\ngroup 1 at T3.\nConclusion: Combination of orthodontic treatment and periodontal surgery is an effective treatment for adult\npatients that decreases the duration of active treatment and reduces the risk of root resorption. Use of a bovine derived\nxenograft with modified corticotomy provided superior benefits in terms of increased bone density than\ndid the use of bioactive glass....
Background: Successful pulp regeneration depends on identification of pulp stem cells capable of differentiation\nunder odontoblastic lineage and producing pulp-dentinal like structure. Recent studies demonstrate that plateletderived\ngrowth factor (PDGF) plays an important role in damage repair and tissue regeneration. The aim of this\nstudy was to identify a subpopulation of dental pulp cells responsive to PDGF and with dentin regeneration potential.\nMethods: Pulp tissues were isolated from 12 freshly extracted human impacted third molars. Pulp cells were\nsorted by their expression of PDGFR�² and stem cell marker genes via flow cytometry. For the selected cells,\nproliferation was analyzed by a colorimetric cell proliferation assay, differentiation was assessed by real time PCR\ndetection the expression of odontoblast marker genes, and mineralization was evaluated by Alizarin Red S\nstaining. GFP marked PDGFR�²+/c-kit+ pulp cells were transplanted into emptied root canals of nude rat lower left\nincisors. Pulp-dentinal regeneration was examined by immunohistochemistry.\nResults: PDGFR�²+/c-kit+ pulp cells proliferated significantly faster than whole pulp cells. In mineralization media,\nPDGFR�²+/c-kit+ pulp cells were able to develop under odontoblastic linage as demonstrated by a progressively\nincreased expression of DMP1, DSPP, and osteocalcin. BMP2 seemed to enhance whereas PDGF-BB seemed to\ninhibit odontoblastic differentiation and mineralization of PDGFR�²+/c-kit+ pulp cells. In vivo root canal transplantation\nstudy revealed globular dentin and pulp-like tissue formation by PDGFR�²+/c-kit+ cells.\nConclusions: PDGFR�²+/c-kit+ pulp cells appear to have pulp stem cell potential capable of producing dentinal like\nstructure in vitro and in vivo....
Background: The aim of this study was to compare the external apical root resorption (EARR) in patients receiving\nfixed orthodontic treatment with self-ligating or conventional brackets.\nMethods: Studies comparing the EARR between orthodontic patients using self-ligating or conventional brackets\nwere identified through electronic search in databases including CENTRAL, PubMed, EMBASE, China National\nKnowledge Infrastructure (CNKI) and SIGLE, and manual search in relevant journals and reference lists of the\nincluded studies until Apr 2016. The extraction of data and risk of bias evaluation were conducted by two\ninvestigators independently. The original outcome underwent statistical pooling by using Review Manager 5.\nResults: Seven studies were included in the systematic review, out of which, five studies were statistically pooled\nin meta-analysis. The value of EARR of maxillary central incisors in the self-ligating bracket group was significantly\nlower than that in the conventional bracket group (SMD âË?â??0.31; 95% CI: âË?â??0.60ââ?¬â??âË?â??0.01). No significant differences in\nother incisors were observed between selfâË?â??ligating and conventional brackets.\nConclusions: Current evidences suggest self-ligating brackets do not outperform conventional brackets in reducing\nthe EARR in maxillary lateral incisors, mandible central incisors and mandible lateral incisors. However, self-ligating\nbrackets appear to have an advantage in protecting maxillary central incisor from EARR, which still needs to be\nconfirmed by more high-quality studies....
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