Biomedical subjects

Fang Qian

Publications and source records attributed to Fang Qian.

At least 19 recordsLinked to original sources

PubMed2026

Genetic and epigenetic contributors to cleft laterality: evidence from monozygotic mirror twins and replication cohorts.

Nonsyndromic cleft lip (nsCL) exhibits a non-random laterality pattern, with left-sided clefts occurring twice as frequently as right-sided clefts. The molecular mechanisms underlying this laterality bias remain poorly understood. We performed whole-genome sequencing and methylation profiling on a family comprising monozygotic twins with mirror-image nsCL, their affected mother, and unaffected father and brother. We conducted three independent replications via publicly available whole genome data; genome-wide methylation analysis in 38 individuals with unilateral cleft; and validation of methylation results in the top 3 candidate genes in 385 unrelated individuals with unilateral nonsyndromic cleft lip with or without cleft palate (nsCL/P) (DNA from blood or saliva). We identified a variant in FGF20 (p.Ile79Val) shared by the twins and their mother. We observed laterality and severity-associated methylation differences in three main genes. ARID5B showed higher methylation in left clefts (saliva, P = .001; blood, P = .032). ZFP57 demonstrated a strong cleft-extent effect, with cleft lip and palate (CLP) showing markedly higher methylation than cleft lip only (CL) (LCLP vs. RCL padj = 0.0004; LCLP vs. LCL padj = 0.019). HOOK2 displayed a cross-tissue cleft-extent effect in the opposite direction-CLP subtypes were hypomethylated relative to CL-only subtypes in blood (P < .0001) and saliva (P = .0008). This study provides evidence that DNA methylation patterns play a role in both the laterality and severity of cleft lip. ARID5B provides a consistent laterality signal across tissues, while ZFP57 and HOOK2 track palatal involvement independently of side. Together, these findings suggest that epigenetic variation acts downstream of genetic predisposition to shape cleft phenotypes.

Humans↗

PubMed2026

Genetic and Epigenetic Contributors to Cleft Laterality: Evidence from Monozygotic Mirror Twins and Replication Cohorts.

Nonsyndromic cleft lip (nsCL) exhibits a non-random laterality pattern, with left-sided clefts occurring approximately twice as frequently as right-sided clefts. The molecular mechanisms underlying this laterality bias remain poorly understood. We performed whole-genome sequencing and methylation profiling on a family comprising monozygotic twins with mirror-image nsCL, their affected mother, and unaffected father and brother. We conducted three independent replications via (1) publicly available whole genome data; (2) genome-wide methylation analysis in 38 individuals with unilateral cleft; and (3) validation of methylation results in the top 3 candidate genes in 385 unrelated individuals with unilateral clefts (DNA from blood or saliva). We identified a variant in FGF20 (p.Ile79Val) shared by the twins and their mother. We observed laterality and severity-associated methylation differences in three main genes. ARID5B showed higher methylation in left clefts (saliva, p=0.001; blood, p=0.032). ZFP57 demonstrated a strong cleft-extent effect, with cleft lip and palate (CLP) showing markedly higher methylation than cleft lip only (CL) (LCLP vs. RCL padj=0.0004; LCLP vs. LCL padj = 0.019). HOOK2 displayed a cross-tissue cleft-extent effect in the opposite direction - CLP subtypes were hypomethylated relative to CL-only subtypes in blood (p<0.0001) and saliva p=0.0008). This study provides evidence that DNA methylation patterns plays a role in both the laterality and severity of cleft lip. ARID5B provides a consistent laterality signal across tissues, while ZFP57 and HOOK2 track palatal involvement independently of side. Together, these findings suggest that epigenetic variation acts downstream of genetic predisposition to shape cleft phenotypes.

Journal Article↗

PubMed2006

A BAFF antagonist suppresses experimental autoimmune encephalomyelitis by targeting cell-mediated and humoral immune responses.

BAFF [B cell-activating factor of the tumour necrosis factor (TNF) family] and APRIL (a proliferation-inducing ligand) are two TNF family members with shared receptors. While, physiological roles for APRIL are not fully understood, BAFF is critical for B cell homeostasis and also acts as a co-stimulator of T cells. Using a B and T cell-mediated mouse model of multiple sclerosis (MS), myelin oligodendrocyte glycoprotein (MOG)-induced experimental autoimmune encephalomyelitis (EAE), we observed that a BAFF/APRIL antagonist (soluble BCMA-Fc) inhibited central nervous system inflammation and demyelination such that it suppressed the onset and progression of clinical symptoms of EAE. In addition to dramatically reducing the titre of MOG-specific auto-antibodies, this treatment also induced a switch in the subtype of the T(h) cell population characterized by marked alterations in cytokine production following re-stimulation with MOG in vitro. Indeed, hBCMA-Fc therapy led to significant increases in the level of transforming growth factor beta, while the levels of T(h)1 cytokines were markedly diminished. These results not only identify BAFF as a critical factor in maintaining humoral immunity in EAE but also support its role in T lymphocyte responses. Our findings demonstrate that hBCMA-Fc acts on both effector arms of the immune response in EAE, a characteristic that may be of significant therapeutic value in the treatment of MS.

Animals↗

PubMed2006

Structure activity relationships of monocyte chemoattractant proteins in complex with a blocking antibody.

Monocyte chemoattractant proteins (MCPs) are cytokines that direct immune cells bearing appropriate receptors to sites of inflammation or injury and are therefore attractive therapeutic targets for inhibitory molecules. 11K2 is a blocking mouse monoclonal antibody active against several human and murine MCPs. A 2.5 A structure of the Fab fragment of this antibody in complex with human MCP-1 has been solved. The Fab blocks CCR2 receptor binding to MCP-1 through an adjacent but distinct binding site. The orientation of the Fab indicates that a single MCP-1 dimer will bind two 11K2 antibodies. Several key residues on the antibody and on human MCPs were predicted to be involved in antibody selectivity. Mutational analysis of these residues confirms their involvement in the antibody-chemokine interaction. In addition to mutations that decreased or disrupted binding, one antibody mutation resulted in a 70-fold increase in affinity for human MCP-2. A key residue missing in human MCP-3, a chemokine not recognized by the antibody, was identified and engineering the preferred residue into the chemokine conferred binding to the antibody.

Amino Acid Sequence↗

PubMed2006

Formation of virus-like clusters is an intrinsic property of the tumor necrosis factor family member BAFF (B cell activating factor).

The oligomeric state of BAFF (B cell activing factor), a tumor necrosis factor (TNF) family cytokine that plays a critical role in B cell development and survival, has been the subject of recent debate. Myc-tagged BAFF starting at residue Gln136 was previously reported to crystallize as trimers at pH 4.5, whereas a histidine-tagged construct of BAFF, starting at residue Ala134, formed a virus-like cluster containing 60 monomers when crystallized at pH 9.0. The formation of the BAFF 60-mer was pH dependent, requiring pH >or= 7.0. More recently, 60-mer formation was suggested to be artificially induced by the histidine tag, and it was proposed that BAFF, like all other TNF family members, is trimeric. We report here that a construct of BAFF with no amino-terminal tag (Ala134-BAFF) can form a 60-mer in solution. Using size exclusion chromatography and static light scattering to monitor trimer to 60-mer ratios in BAFF preparations, we find that 60-mer formation is pH-dependent and requires histidine 218 within the DE loop of BAFF. Biacore measurements established that the affinity of Ala134-BAFF for the BAFF receptor BAFFR/BR3 is similar to that of myc-Gln136-BAFF, which is exclusively trimeric in solution. However, Ala134-BAFF is more efficacious than myc-Gln136-BAFF in inducing B cell proliferation in vitro. We additionally show that BAFF that is processed and secreted by 293T cells transfected with full-length BAFF, or by a histiocytic lymphoma cell line (U937) that expresses BAFF endogenously, forms a pH-dependent 60-mer in solution. Our results indicate that the formation of the 60-mer in solution by the BAFF extracellular domain is an intrinsic property of the protein, and therefore that this more active form of BAFF may be physiologically relevant.

Animals↗

PubMed2006

Identification of a putative mitochondrial RNA polymerase from Physarum polycephalum: characterization, expression, purification, and transcription in vitro.

Mitochondrial RNA polymerases (mtRNAPs) are necessary for the biogenesis of mitochondria and for proper mitochondrial function since they transcribe genes on mtDNA for tRNAs, rRNAs, and mRNAs. The unique type of RNA editing identified in mitochondria of Physarum polycephalum is thought to be closely associated with transcription, and as such, RNA editing activity would be expected to be closely associated with the mtRNAP. In order to better characterize the role of mtRNAPs in mitochondrial biogenesis and to determine the role of the Physarum mtRNAP in RNA editing, the cDNA of the Physarum mtRNAP was identified using PCR and degenerate primers designed from conserved motifs in mtRNAPs. This amplification product was used to screen a cDNA library for the cDNA corresponding to the Physarum mtRNAP. A cDNA corresponding to a 3.2 kb transcript containing a 997 codon open reading frame was identified. The amino acid sequence inferred from the open reading frame contains motifs characteristic of mtRNAPs. To confirm that a cDNA for an RNA polymerase had been isolated, the cDNA was expressed in E. coli as an N-terminal maltose binding protein (MBP) fusion protein. The fusion protein was purified by affinity chromatography and shown to have DNA-directed RNA polymerase activity. This functional mtRNAP will be useful for in vitro studies of mitochondrial transcription and RNA editing.

Animals↗

PubMed2006

Dopant-free GaN/AlN/AlGaN radial nanowire heterostructures as high electron mobility transistors.

We report the rational synthesis of dopant-free GaN/AlN/AlGaN radial nanowire heterostructures and their implementation as high electron mobility transistors (HEMTs). The radial nanowire heterostructures were prepared by sequential shell growth immediately following nanowire elongation using metal-organic chemical vapor deposition (MOCVD). Transmission electron microscopy (TEM) studies reveal that the GaN/AlN/AlGaN radial nanowire heterostructures are dislocation-free single crystals. In addition, the thicknesses and compositions of the individual AlN and AlGaN shells were unambiguously identified using cross-sectional high-angle annular darkfield scanning transmission electron microscopy (HAADF-STEM). Transport measurements carried out on GaN/AlN/AlGaN and GaN nanowires prepared using similar conditions demonstrate the existence of electron gas in the undoped GaN/AlN/AlGaN nanowire heterostructures and also yield an intrinsic electron mobility of 3100 cm(2)/Vs and 21,000 cm(2)/Vs at room temperature and 5 K, respectively, for the heterostructure. Field-effect transistors fabricated with ZrO(2) dielectrics and metal top gates showed excellent gate coupling with near ideal subthreshold slopes of 68 mV/dec, an on/off current ratio of 10(7), and scaled on-current and transconductance values of 500 mA/mm and 420 mS/mm. The ability to control synthetically the electronic properties of nanowires using band structure design in III-nitride radial nanowire heterostructures opens up new opportunities for nanoelectronics and provides a new platform to study the physics of low-dimensional electron gases.

Aluminum Compounds↗

PubMed2006

Effects of exogenous collagenase and cholesterol esterase on the durability of the resin-dentin bond.

PURPOSE: The purpose of this work was to determine microtensile dentin bond strengths (microTBS) of dentin-resin composite bonds after three-month storage in artificial saliva containing either collagenase (COL) or cholesterol esterase (EST). The null hypothesis tested is that the resin-dentin bond strength is equivalent for each storage medium at the tested storage times. MATERIALS AND METHODS: Resin composite was bonded to occlusal dentin, and microTBS specimens were formed and stored in the artificial saliva, COL, EST, or synthetic oil. After 24 h and 12-week storage, microTBS was determined and failure modes were characterized by SEM. The interfacial ultrastructure was evaluated by transmission electron microscopy as unstained and stained sections (phosphotungstic acid/uranyl acetate). Statistical analysis was performed by ANOVA and Weibull survival analyses at the 0.05 level of statistical significance. RESULTS: There were significantly weaker bond strengths after 12 weeks for all experimental storage media (p < 0.001). Artificial saliva containing EST lowered bond strengths to a significantly greater extent than did COL after 12 weeks of storage, while no difference between these groups could be discerned after 24 h. Therefore, the null hypothesis of this experiment is rejected. CONCLUSION: Exogenous enzymatic challenge to resin-dentin bonds decreased bond durability only with EST. However, when further challenges to ideal infiltration of the comonomers into the hybrid layer were carried out using inadequate removal of solvent, additional alterations in hybrid layer ultrastructure were discerned by TEM that may represent different potential degradative processes. The contribution of endogenous enzymatic challenges to the primary degradative process, ie, hydrolysis, is unknown and deserves continued attention.

Acid Etching, Dental↗

PubMed2006

Prevention of demineralization by CO2 and Er,Cr:YSGG laser irradiation of overdenture abutments.

PURPOSE: To assess the effects of Er,Cr:YSGG and CO2 laser irradiation on the prevention of demineralization of overdenture abutments. METHODS: 32 human canines, premolars, and molars were acquired, cleaned, and scaled. They were randomly divided into two groups. Each tooth had two windows on the occlusal cut dentin. One window on each tooth was irradiated by either Er,Cr:YSGG or CO2 laser, while the other window served as a control. After pH cycling at pH 5.5 for 18 days and pH 4.7 for 16 days, the teeth were sectioned and analyzed using polarized light microscopy with water as the imbibing medium. RESULTS: The Er,Cr:YSGG irradiated dentin had a mean lesion depth of 207 +/- 27 microm while its control had a mean lesion depth of 209 +/- 34 microm. The CO2 laser irradiated dentin had a mean lesion depth of 185 +/- 24 microm while its control had a mean lesion depth of 205 +/- 22 microm. Based on paired t-tests Er,Cr:YSGG laser irradiation of dentin did not reduce demineralization when compared to the controls (P= 0.81), while CO2 laser irradiation of dentin showed that it helped reduce demineralization when compared to the controls (P= 0.025).

Adult↗

PubMed2005

Selectivity of BAFF/BLyS and APRIL for binding to the TNF family receptors BAFFR/BR3 and BCMA.

BAFF (B cell activating factor of the TNF family, also known as BlyS and TALL-1), a TNF family cytokine critical for the development and function of B cells, has been reported to bind to three receptors, BCMA (B cell maturation protein), TACI (transmembrane activator and CAML [calcium-modulator and cyclophilin ligand] interactor), and BAFFR (BAFF receptor), but with widely conflicting values for the affinity and selectivity of binding. BCMA and TACI additionally bind APRIL (a proliferation-inducing ligand), the TNF family ligand most homologous to BAFF. Using soluble, monomeric forms of the receptors, we demonstrate that BAFFR binds BAFF with K(D) approximately 16 nM, while BCMA binds with K(D) approximately 1.6 microM, indicating a approximately 100-fold selectivity for binding to BAFFR over BCMA. APRIL shows the opposite selectivity, binding to BCMA with K(D) approximately 16 nM while showing no detectable affinity for BAFFR (K(D) > 3 microM). The binding of BAFF or APRIL to these receptors is highly sensitive to assay-dependent avidity effects, likely explaining the widely ranging affinity values reported in the literature. Binding of BAFF to BCMA-Fc, a bivalent fusion protein consisting of the extracellular domain of BCMA fused to the hinge and CH1 and CH2 domains of human IgG1, in solution or coated onto an ELISA plate gave apparent binding affinities of approximately 0.63 and approximately 0.15 nM, respectively, compared to values of K(D(app)) <or= 30 and approximately 100 pM for the corresponding BAFFR/IgG1 fusion protein, BAFFR-Fc. The high selectivity of BAFF for BAFFR versus BCMA is thus partly obscured in these multivalent assays. The intrinsically high selectivity inferred from the measurements with monomeric receptor correlates well with in vivo data from knockout mice, providing a possible explanation for the observations that interruption of the BAFFR gene in the A/WySnJ mouse produces a phenotype similar to the BAFF knockout mouse, while the BCMA knockout mouse has no discernible B cell phenotype.

Animals↗

PubMed2005

Buccal corridors and smile esthetics.

PURPOSE: The purpose of this study was to determine the influence of buccal corridors on smile attractiveness when judged by lay persons. MATERIAL: Full-face color slides of 10 randomly selected smiling subjects (5 women, 5 men) were digitized. The maxillary posterior dentitions for all subjects were digitally altered to produce a range of smile fullness: narrow (28% buccal corridor), medium-narrow (22% buccal corridor), medium (15% buccal corridor), medium-broad (10% buccal corridor), and broad (2% buccal corridor). The 5 images of each subject were paired into 11 possible combinations, and the resulting 110 pairings were randomly projected to a panel of 30 adult lay persons who compared the 2 images in each pair for smile attractiveness. RESULTS: Statistical analysis with the Wilcoxon signed-rank and rank-sum tests showed that (1) a broader smile (minimal buccal corridor) was judged by lay persons to be more attractive than a narrow smile (larger buccal corridors), and (2) no significant differences were found in judging between male and female subjects or between male and female judges. CONCLUSIONS: Having minimal buccal corridors is a preferred esthetic feature in both men and women, and large buccal corridors should be included in the problem list during orthodontic diagnosis and treatment planning.

Adult↗

PubMed2005

A retrospective review of treatment of the odontogenic keratocyst.

PURPOSE: The purpose of this study was to evaluate different surgical treatment methods for odontogenic keratocysts and the outcome of those treatments over a 25-year period. PATIENTS AND METHODS: A retrospective review was performed of 40 patient charts treated at the University of Iowa Hospitals and Clinics (Iowa City, IA) from 1977 to 2002 with the diagnosis of odontogenic keratocyst. Demographic data were collected along with lesion location, symptoms present at initial presentation, surgical treatment rendered, length of follow-up, and incidence of recurrence. RESULTS: Surgical treatments included enucleation, enucleation with Carnoy's solution, peripheral ostectomy, peripheral ostectomy with Carnoy's solution, and en bloc resection. Recurrence was found in 9 to 40 patients. Seven of 9 recurrences (78%) occurred in 5 years or less, with 2 (22%) occurring more than 5 years after initial treatment. Patients treated with enucleation had a recurrence rate of 54.5% (6 of 11 patients). One of 2 patients treated with enucleation and Carnoy's solution had a recurrence. Those treated with peripheral ostectomy had a recurrence rate of 18.2% (2 of 11). Peripheral ostectomy with Carnoy's solution had no recurrences (0/13). CONCLUSION: Treatment of an odontogenic keratocyst with peripheral ostectomy, with or without the use of Carnoy's solution, had a significantly lower rate of recurrence. Treatment with enucleation, with or without the use of Carnoy's solution was associated with a significantly higher recurrence rate.

Acetic Acid↗

PubMed2005

General synthesis of manganese-doped II-VI and III-V semiconductor nanowires.

A general approach for the synthesis of manganese-doped II-VI and III-V nanowires based on metal nanocluster-catalyzed chemical vapor deposition has been developed. High-resolution transmission electron microscopy and energy-dispersive X-ray spectroscopy studies of Mn-doped CdS, ZnS, and GaN nanowires demonstrate that the nanowires are single-crystal structures and homogeneously doped with controllable concentrations of manganese ions. Photoluminescence measurements of individual Mn-doped CdS and ZnS nanowires show characteristic pseudo-tetrahedral Mn2+ ((4)T1-->(6)A1) transitions that match the corresponding transitions in bulk single-crystal materials well. Photoluminescence studies of Mn-doped GaN nanowires suggest that manganese is incorporated as a neutral (Mn3+) dopant that partially quenches the GaN band-edge emission. The general and controlled synthesis of nanowires doped with magnetic metal ions opens up opportunities for fundamental physical studies and could lead to the development of nanoscale spintronic devices.

Crystallization↗

PubMed2005

Core/multishell nanowire heterostructures as multicolor, high-efficiency light-emitting diodes.

We report the growth and characterization of core/multishell nanowire radial heterostructures, and their implementation as efficient and synthetically tunable multicolor nanophotonic sources. Core/multishell nanowires were prepared by metal-organic chemical vapor deposition with an n-GaN core and InxGa1-xN/GaN/p-AlGaN/p-GaN shells, where variation of indium mole fraction is used to tune emission wavelength. Cross-sectional transmission electron microscopy studies reveal that the core/multishell nanowires are dislocation-free single crystals with a triangular morphology. Energy-dispersive X-ray spectroscopy clearly shows shells with distinct chemical compositions, and quantitatively confirms that the thickness and composition of individual shells can be well controlled during synthesis. Electrical measurements show that the p-AlGaN/p-GaN shell structure yields reproducible hole conduction, and electroluminescence measurements demonstrate that in forward bias the core/multishell nanowires function as light-emitting diodes, with tunable emission from 365 to 600 nm and high quantum efficiencies. The ability to synthesize rationally III-nitride core/multishell nanowire heterostructures opens up significant potential for integrated nanoscale photonic systems, including multicolor lasers.

Journal Article↗

PubMed2005

Students' comfort level in treating vulnerable populations and future willingness to treat: results prior to extramural participation.

This study analyzed senior dental students' perceptions prior to extramural rotations for comfort and future willingness to treat patients with special needs and other vulnerable groups. The sample included 690 University of Iowa senior dental students who graduated from 1992 through 2004. These students completed a questionnaire concerning twelve vulnerable population groups. Logistic regression models were performed, using student comfort and future willingness to treat each group as the dependent variable. There was a wide percentage of range of comfort with these groups, yet there was no individual group that more than 60 percent of these students were willing to treat in their future practices. Generally, prior experience with the group had a positive impact on comfort level. When gender was included in the regression models, male students were more likely to express comfort. In all instances except one, experience had a positive influence on perceived future willingness to treat the associated group. However, younger graduates had a greater willingness to treat. When controlling for other variables within the future willingness to treat models, comfort was statistically significant only for HIV+/AIDS and non-English speaking groups. This study provides insight about comfort with and perceived future willingness to treat special needs and other vulnerable patient groups.

Acquired Immunodeficiency Syndrome↗

PubMed2004

B cell-activating factor belonging to the TNF family (BAFF)-R is the principal BAFF receptor facilitating BAFF costimulation of circulating T and B cells.

BAFF (B cell-activating factor belonging to the TNF family) is a cell survival and maturation factor for B cells, and overproduction of BAFF is associated with systemic autoimmune disease. BAFF binds to three receptors, BAFF-R, transmembrane activator and calcium modulator and cyclophilin ligand interactor (TACI), and B cell maturation Ag (BCMA). Using specific mAbs, BAFF-R was found to be the predominant BAFF receptor expressed on peripheral B cells, in both humans and mice, and antagonist mAbs to BAFF-R blocked BAFF-mediated costimulation of anti- micro responses. The other BAFF receptors showed a much more restricted expression pattern, suggestive of specialized roles. BCMA was expressed by germinal center B cells, while TACI was expressed predominantly by splenic transitional type 2 and marginal zone B cells, as well as activated B cells, but was notably absent from germinal center B cells. BAFF was also an effective costimulator for T cells, and this costimulation occurs entirely through BAFF-R. BAFF-R, but not TACI or BCMA, was expressed on activated/memory subsets of T cells, and T cells from BAFF-R mutant A/WySnJ mice failed to respond to BAFF costimulation. Thus, BAFF-R is important not only for splenic B cell maturation, but is the major mediator of BAFF-dependent costimulatory responses in peripheral B and T cells.

Animals↗

PubMed2004

Postprocedural problems in an overdenture population: a longitudinal study.

This study reports on endodontic and other post-procedural problems experienced by overdenture patients from 1973 to 1996. There were 395 subjects enrolled in the study; 273 fulfilled the recall criteria. At recall, all subjects were examined by a single examiner, and appropriate maintenance care was performed. The 273 subjects had 666 abutments and 626 endodontically treated teeth; of these, 51 subjects had postprocedural problems in 81 teeth. Thus, 87.1% of the endodontically treated teeth had no postprocedural problems, and 12.9% had postprocedural problems. Of the subpopulation with postprocedural problems, the most common problem was endodontically treated teeth developing periradicular lesions (37.0%) because of recurrent caries causing loss of the restoration sealing the root canal. Twenty of the 30 teeth were successfully retreated. The next most common problem was vertical root fractures (30.9%), followed by vital teeth developing periradicular lesions (19.8%). Most of the failures could have been prevented by better oral hygiene. Vertical root fractures were statistically associated with abutments in the maxilla and opposed by natural teeth; protection of these abutments with thimble crowns could prevent fractures.

Adolescent↗

PubMed2004

Twelve-month sealant retention in a school-based program using a self-etching primer/adhesive.

OBJECTIVES: Very little independent research has been done on the new self-etching primer/adhesives in dentistry. A recent clinical study compared two sealant application techniques involving self-etching primer adhesives and the traditional phosphoric acid etch. The purpose of this study was to compare these two techniques in an Iowa school-based sealant program. METHODS: Twelve-month sealant retention data on 208 students from the Des Moines, Iowa, school-based sealant program were analyzed retrospectively. RESULTS: Sealant retention reported at the person level showed that 60 percent of the students who received sealants at the five schools had to be recalled at one year to have one or more surfaces resealed. A logistic regression model at the person level demonstrated that the phosphoric acid technique was six times as likely to have retention of all the sealed tooth surfaces as those sealed with Prompt-L-Pop. CONCLUSIONS: In this study, many students had to be recalled to the chair 12 months after sealant application due to incomplete retention. Though sealants were retained in larger numbers with phosphoric acid, overall sealant retention at the tooth level was lower than previously published for clinical studies and school-based programs. Examining retention data at the person level, however, allows program administrators to plan resources more effectively and reevaluate sealant protocol to ensure as few children return for sealant reapplication.

Acid Etching, Dental↗