Interleukin-27-induced HIV-resistant dendritic cells suppress reveres transcription following virus entry in an SPTBN1, Autophagy, and YB-1 independent manner.

Interleukin (IL)-27, a member of the IL-12 family of cytokines, induces human immunodeficiency virus (HIV)-resistant monocyte-derived macrophages and T cells. This resistance is mediated via the downregulation of spectrin beta, non-erythrocytic 1 (SPTBN1), induction of autophagy, or suppression of the acetylation of Y-box binding protein-1 (YB-1); however, the role of IL-27 administration during the induction of immature monocyte-derived dendritic cells (iDC) is poorly investigated. In the current study, we investigated the function of IL-27-induced iDC (27DC) on HIV infection. 27DC inhibited HIV infection by 95 ± 3 % without significant changes in the expression of CD4, CCR5, and SPTBN1 expression, autophagy induction and acetylation of YB-1 compared to iDC. An HIV proviral DNA copy number assay displayed that 27DC suppressed reverse transcriptase (RT) reaction without influencing the virus entry. A DNA microarray analysis was performed to identify the differentially expressed genes between 27DC and iDC. Compared to iDC, 51 genes were differentially expressed in 27DC, with more than 3-fold changes in four independent donors. Cross-reference analysis with the reported 2,214 HIV regulatory host genes identified nine genes as potential interests: Ankyrin repeat domain 22, Guanylate binding protein (GBP)-1, -2, -4, -5, Stabilin 1, Serpin family G member 1 (SERPING1), Interferon alpha inducible protein 6, and Interferon-induced protein with tetratricopeptide repeats 3. A knock-down study using si-RNA failed to determine a key factor associated with the anti-HIV activity due to the induction of robust amounts of off-target effects. Overexpression of each protein in cells had no impact on HIV infection. Thus, we could not define the mechanism of the anti-HIV effect in 27DC. However, our findings indicated that IL-27 differentiates monocytes into HIV-resistant DC, and the inhibitory mechanism differs from IL-27-induced HIV-resistant macrophages and T cells.

Interleukin-27-induced HIV-resistant dendritic cells suppress reveres transcription following virus entry in an SPTBN1, autophagy, and YB-1 independent manner.

Interleukin (IL)-27, a member of the IL-12 family of cytokines, induces human immunodeficiency virus (HIV)-resistant monocyte-derived macrophages and T cells. This resistance is mediated via the downregulation of spectrin beta, non-erythrocytic 1 (SPTBN1), induction of autophagy, or suppression of the acetylation of Y-box binding protein-1 (YB-1); however, the role of IL-27 administration during the induction of immature monocyte-derived dendritic cells (iDC) is poorly investigated. In the current study, we investigated the function of IL-27-induced iDC (27DC) on HIV infection. 27DC inhibited HIV infection by 95 ± 3% without significant changes in the expression of CD4, CCR5, and SPTBN1 expression, autophagy induction and acetylation of YB-1 compared to iDC. An HIV proviral DNA copy number assay displayed that 27DC suppressed reverse transcriptase (RT) reaction without influencing the virus entry. A DNA microarray analysis was performed to identify the differentially expressed genes between 27DC and iDC. Compared to iDC, 51 genes were differentially expressed in 27DC, with more than 3-fold changes in four independent donors. Cross-reference analysis with the reported 2,214 HIV regulatory host genes identified nine genes as potential interests: Ankyrin repeat domain 22, Guanylate binding protein (GBP)-1, -2, -4, -5, Stabilin 1, Serpin family G member 1 (SERPING1), Interferon alpha inducible protein 6, and Interferon-induced protein with tetratricopeptide repeats 3. A knock-down study using si-RNA failed to determine a key factor associated with the anti-HIV activity due to the induction of robust amounts of off-target effects. Overexpression of each protein in cells had no impact on HIV infection. Thus, we could not define the mechanism of the anti-HIV effect in 27DC. However, our findings indicated that IL-27 differentiates monocytes into HIV-resistant DC, and the inhibitory mechanism differs from IL-27-induced HIV-resistant macrophages and T cells.

Co-operative membrane disruption between cell-penetrating peptide and cargo: implications for the therapeutic use of the Bcl-2 converter peptide D-NuBCP-9-r8.

Delivering apoptosis inducing peptides to cells is an emerging area in cancer and molecular therapeutics. Here, we have identified an alternative mechanism of action for the proapoptotic chimeric peptide D-NuBCP-9-r8. Integral to D-NuBCP-9-r8 is the Nur-77-derived D-isoform sequence fsrslhsll that targets Bcl-2, and the cell-penetrating peptide (CPP) octaarginine (r8) that is required for intracellular delivery. We find that the N-terminal phenylalanine of fsrslhsll acts in synergy with the cell-penetrating moiety to enhance peptide uptake at low nontoxic levels and cause rapid membrane blebbing and cell necrosis at higher (IC(50)) concentrations. These effects were not observed when a single phenylalanine-alanine mutation was introduced at the N-terminus of D-NuBCP-9-r8. Using primary samples from chronic lymphocytic leukemia (CLL) patients and cancer cell lines, we show that NuBCP-9-r8 induced toxicity, via membrane disruption, is independent of Bcl-2 expression. Overall, this study demonstrates a new mechanism of action for this peptide and cautions its use as a highly specific entity for targeting Bcl-2. For delivery of therapeutic peptides the work emphasizes that key amino acids in cargo, located several residues away from the cell-penetrating sequence, can significantly influence their cellular uptake and mode of action.

Chemical synthesis of cell-permeable apoptotic peptides from in vivo produced proteins.

In vivo synthesis of peptides by bacterial expression has developed into a reliable alternative to solid-phase peptide synthesis. A significant drawback of in vivo methods is the difficulty with which gene products can be modified post-translationally. Here, we present a method for the facile modification of peptides generated in bacterial hosts after cyanogen bromide cleavage at C-terminal methionines. Reaction of the resulting homoserine lactones with propargylamine allows efficient and selective modification with a wide variety of chemicals such as fluorescent dyes, biotin derivatives, polyprenyls, lipids, polysaccharides, or peptides. Attachment of the cell penetrating peptide octa-arginine (R(8)) to peptides derived from the proapoptotic tumor suppressor Bak BH3 led to efficient cellular uptake and subsequent cytochrome c release from mitochondria, culminating in induction of apoptosis similar to that observed with peptides linked to R(8) via the peptide backbone. These results highlight the significant potential for use of such tools in live cells.

Digital Approaches to Music-Making for People With Dementia in Response to the COVID-19 Pandemic: Current Practice and Recommendations.

Before COVID-19, dementia singing groups and choirs flourished, providing activity, cognitive stimulation, and social support for thousands of people with dementia in the UK. Interactive music provides one of the most effective psychosocial interventions for people with dementia; it can allay agitation and promote wellbeing. Since COVID-19 has halted the delivery of in-person musical activities, it is important for the welfare of people with dementia and their carers to investigate what alternatives to live music making exist, how these alternatives are delivered and how their accessibility can be expanded. This community case study examines recent practice in online music-making in response to COVID-19 restrictions for people with dementia and their supporters, focusing on a UK context. It documents current opportunities for digital music making, and assesses the barriers and facilitators to their delivery and accessibility. Online searches of video streaming sites and social media documented what music activities were available. Expert practitioners and providers collaborated on this study and supplied input about the sessions they had been delivering, the technological challenges and solutions they had found, and the responses of the participants. Recommendations for best practice were developed and refined in consultation with these collaborators. Over 50 examples of online music activities were identified. In addition to the challenges of digital inclusion and accessibility for some older people, delivering live music online has unique challenges due to audio latency and sound quality. It is necessary to adapt the session to the technology's limitations rather than expect to overcome these challenges. The recommendations highlight the importance of accessibility, digital safety and wellbeing of participants. They also suggest ways to optimize the quality of their musical experience. The pandemic has prompted innovative approaches to deliver activities and interventions in a digital format, and people with dementia and their carers have adapted rapidly. While online music is meeting a clear current need for social connection and cognitive stimulation, it also offers some advantages which remain relevant after COVID-19 restrictions are relaxed. The recommendations of this study are intended to be useful to musicians, dementia care practitioners, and researchers during the pandemic and beyond.

Low concentration thresholds of plasma membranes for rapid energy-independent translocation of a cell-penetrating peptide.

The exact mechanisms by which cell-penetrating peptides such as oligo-arginines and penetratin cross biological membranes has yet to be elucidated, but this is required if they are to reach their full potential as cellular delivery vectors. In the present study, qualitative and quantitative analysis of the influence of temperature, peptide concentration and plasma membrane cholesterol on the uptake and subcellular distribution of the model cell-penetrating peptide octa-arginine was performed in a number of suspension and adherent cell lines. When experiments were performed on ice, the peptide at 2 microM extracellular concentration efficiently entered and uniformly labelled the cytoplasm of all the suspension cells studied, but a 10-fold higher concentration was required to observe similar results in adherent cells. At 37 degrees C and at higher peptide concentrations, time-lapse microscopy experiments showed that the peptide rapidly penetrated the entire plasma membrane of suspension cells, with no evidence of a requirement for nucleation zones to promote this effect. Cholesterol depletion with methyl-beta-cyclodextrin enhanced translocation of octa-arginine across the plasma membrane of suspension cells at 37 degrees C, but decreased overall peptide accumulation. Under the same conditions in adherent cells this agent had no effect on peptide uptake or distribution. Cholesterol depletion increased the overall accumulation of the peptide at 4 degrees C in KG1a cells, but this effect could be reversed by re-addition of cholesterol as methyl-beta-cyclodextrin-cholesterol complexes. The results highlight the relatively high porosity of the plasma membrane of suspension cells to this peptide, especially at low temperatures, suggesting that this feature could be exploited for delivering bioactive entities.

Assessment of the quality of reporting observational studies in the pediatric dental literature.

PURPOSE: The purpose of this assessment was to evaluate reporting of observational studies in the pediatric dental literature. METHODS: This assessment included the following steps: (1) developing a model for reporting information in clinical dentistry studies; (2) identifying treatment comparisons in pediatric dentistry that were evaluated by at least 5 observational studies; (3) abstracting from these studies any data indicated by applying the reporting model; and (4) comparing available data elements to the desired data elements in the reporting model. RESULTS: The reporting model included data elements related to: (1) patients; (2) providers; (3) treatment details; and (4) study design. Two treatment comparisons in pediatric dentistry were identified with 5 or more observational studies: (1) stainless steel crowns vs amalgams (10 studies); and (2) composite restorations vs amalgam (5 studies). Results from studies comparing the same treatments varied substantially. Data elements from the reporting model that could have explained some of the variation were often reported inadequately or not at all. CONCLUSIONS: Reporting of observational studies in the pediatric dental literature may be inadequate for an informed interpretation of the results. Models similar to that used in this study could be used for developing standards for the conduct and reporting of observational studies in pediatric dentistry.

Effect of topical fluoride and fluoride varnish on in vitro root surface lesions.

PURPOSE: To evaluate the effect of a fluoride varnish on demineralization and remineralization of root surfaces in vitro. METHODS: 80 caries-free teeth were selected from a large pool of extracted anterior and premolar teeth from elderly patients. Acid resistant nail varnish was painted on all surfaces except for a window (l x 4 mm) on the buccal or lingual root surfaces. Teeth were randomly divided into four treatment groups: CONTROL: washed with deionized/distilled water; Daily gel: treated with Karigel-N (5,000 ppm) for 4 minutes daily; Weekly gel: treated with Karigel-N for 4 minutes weekly; and Weekly varnish: treated with Duraflor (22,600 ppm) weekly (the varnish was removed 24 hours after each application). Teeth were then placed in a cycle of demineralization (6 hours at pH 4.3) and remineralization (17 hours at pH 7.0) for 21 days. Half the specimens of each group were brushed with no dentifrice for 10 seconds twice daily. Specimens were evaluated under polarized light microscopy and contact microradiography. The depth of each lesion and width of the remineralization bands were measured. An ANOVA model was used to assess the effect of different treatments. RESULTS: The control group had the deepest lesions and the daily gel group had the shallowest lesions. The weekly varnish group was found to have significantly shallower lesions than the weekly gel group. The varnish brushing subgroup had significantly deeper lesions than varnish non-brushing subgroup (P = 0.01). Remineralization bands were detectable in most lesions. There was no significant difference in band width between different groups (F = 0.634, P = 0.594). However, a significant difference was found when remineralization bands were calculated as percentage of lesion depth between different groups (F = 4.24, P = 0.001). The varnish non-brushing subgroup had significantly higher percentage than the control group, but daily gel non-brushing had the highest percentage. Brushing was a significant factor in the varnish group. Lesions were significantly shallower in the non-brushing varnish subgroup.

Overview of the evidence for clinical interventions in pediatric dentistry.

PURPOSE: The purpose of this report was to describe the quantity of published literature and types of studies supporting the use of 4 pediatric dentistry procedures: (1) ferric sulfate pulpotomy; (2) stainless steel crowns; (3) space maintainers; and (4) atraumatic restorative technique (ART). METHODS: When available, titles and abstracts of reports written in English and published over a 36-year period (1966-2002) concerning these procedures were retrieved from MEDLINE. They were classified using a modified classification scheme that, in addition to the study designs, also considered the 4 dimensions of measuring dental outcomes. RESULTS: The quantity of available literature concerning each dental procedure varied considerably. Even though many reports were published on treatments, only a small proportion of the published literature for each procedure was found to evaluate outcomes, regardless of outcome dimension. Besides outcomes evaluations, studies on techniques, material properties, and review articles comprised a large proportion of the literature. Clinical dimension of outcomes was most commonly studied. Case series and case reports were the most frequently used study designs to report outcomes. CONCLUSIONS: The outcomes-related literature to support some of the commonly performed treatments is limited both in quantity and study types. More reports are needed to develop the evidence base to support the commonly performed procedures in pediatric dental practice. Additional analyses reporting of the literature are also needed to assess internal and external validity of the studies.

Tooth loss in the very old: 13-15-year incidence among elderly Iowans.

OBJECTIVES: Very few studies have reported tooth loss incidence over a period of 10 years or more, and fewer have reported tooth loss occurrence in subjects aged 80 and older, so that the long-term pattern of tooth loss in the very old is largely unknown. This study assessed 13-15-year tooth loss incidence among a cohort of Iowans, aged 65 and older at baseline. METHODS: Oral examinations were conducted on 520 subjects beginning in 1983, and periodically until 1988, with another round of examinations conducted on surviving members of the initial cohort during 1996-98. RESULTS: Of the 73 remaining subjects, 45 subjects lost a total of 153 teeth during the period (mean=2.1 teeth lost), with a maximum of 17 teeth lost. Molars were the most commonly lost teeth, while canines and maxillary incisors were the least commonly lost. Bivariate analyses found that tooth loss was associated with untreated decay at baseline and level of periodontal attachment loss at earlier examinations. Logistic regression identified only greater severity of attachment loss as a significant risk factor for tooth loss (Adjusted odds ratio=2.4, P=0.006). The impact of tooth loss on subjects' lives was assessed using OHIP and other questions. The occurrence of tooth loss over the study period had little impact, but the number of remaining teeth significantly impacted subjects' ability to eat or chew food, swallow, or their willingness to smile. CONCLUSIONS: These results suggest that tooth loss continues in the very old, that periodontal attachment loss is associated with tooth loss in this age group, and that loss of teeth over one's lifetime does affect certain quality-of-life measures.

Anticipated and experienced pain associated with endodontic therapy.

BACKGROUND: The authors compared the levels of anticipated and experienced pain of patients who received endodontic therapy, or ET, with selected patient and dental characteristics. METHODS: Sensory and affective pain outcome measures (pain and unpleasantness) were evaluated by 333 adult patients immediately before and after dental school faculty or residents performed ET. Dentists provided clinical evaluations and a pulpal diagnosis for each tooth and then rated the level of their patients' pain during treatment. RESULTS: Before ET, 43 percent of all patients anticipated high outcome levels, yet only 22 percent experienced high pain levels, and only 18 percent experienced high unpleasantness levels. Outcome levels did not differ by tooth type, pulpal diagnosis, ET history or dental care attendance. Women were significantly more likely to anticipate higher pain and unpleasantness levels than were men. Experienced outcome levels, however, did not differ by sex. Anticipated and experienced outcome levels significantly decreased with increasing age. Dentists' evaluation of their patients' pain levels correlated more highly for female than for male patients. CONCLUSIONS: Pain experienced during ET often is less than anticipated. Younger people anticipate and experience higher pain levels. Women are more likely than men to anticipate, but not necessarily experience, higher pain levels. Dentists are more closely attuned to the pain experiences of their female patients. Clinical Implications. Practitioners could better prepare younger patients and female patients for ET and improve pain communication with male patients. Findings suggest that patients perceive each ET experience as new, implying that dentists should manage patients who have had ET in the past as carefully as those receiving ET for the first time.

BH3 helix-derived biophotonic nanoswitches regulate cytochrome c release in permeabilised cells.

Dynamic physical interactions between proteins underpin all key cellular processes and are a highly attractive area for the development of research tools and medicines. Protein-protein interactions frequently involve α-helical structures, but peptides matching the sequences of these structures usually do not fold correctly in isolation. Therefore, much research has focused on the creation of small peptides that adopt stable α-helical structures even in the absence of their intended protein targets. We show that short peptides alkylated with azobenzene crosslinkers can be used to photo-stimulate mitochondrial membrane depolarization and cytochrome c release in permeabilised cells, the initial events of the intrinsic apoptosis pathway.

Iowa dentists' involvement in care for patients who are homebound.

This study investigated the frequency of Iowa dentists' provision of in-office and out-of-office dental care for people who are homebound, as well as comparing the practice and educational characteristics among dentists who did and did not provide care for patients who were homebound. The authors mailed a survey form to all licensed dentists on the Iowa State Health Professional license database (n = 1,168), excluding pediatric dentists and orthodontists. A second mailing was sent to all nonrespondents four months later, resulting in 638 returned forms for a 54.6% response rate. The questionnaire included two outcome responses associated with the treatment in the dentist's office or in the patient's home for patients who are homebound. About 40% of Iowa dentists reported providing care in the office to patients who are homebound, but care outside of the office was provided by fewer dentists (6%) who had more years of practice experience. These results suggest an increased sense of professional or community responsibility among these older Iowa dentists. Education efforts may increase homebound care and more involvement of younger dentists.

The involvement of Iowa dentists in hospice care.

The relationships between dentist characteristics and professional education with involvement of Iowa dentists in hospice care were investigated. Using the 1999 Iowa Health Professional database, a survey requesting information regarding involvement in and training for care of hospice patients was mailed to all licensed dentists (N = 1,210). Two mailings yielded a 54.6% response rate. Of the 638 dentist respondents, the mean age was 47, 86% were male, 88% general dentists, and 295 (46%) reported providing some treatment for hospice patients. At least one dentist reported providing hospice patient care in 72 of Iowa's 99 counties. About 90% of dentists treating hospice patients were general practitioners. Males were more likely to provide treatment (p < 0.0313). Neither dentist age nor years in practice were significant predictors. Dentists were more likely to treat hospice patients in the office (IO, 40%). The most prevalent treatments were denture relines (31% IO; 71% OO), examinations (16% IO; 68% OO), and emergency treatment (12.5% IO; 53% OO). More than 86% of surveyed dentists indicated that their professional education did not adequately train them to meet the clinical, psychosocial, communication, or spiritual needs of hospice patients.

Cellular uptake, distribution and cytotoxicity of the hydrophobic cell penetrating peptide sequence PFVYLI linked to the proapoptotic domain peptide PAD.

The capacity of cell penetrating peptides (CPPs) to breach biological membranes offers hope for their utilisation as vectors for the delivery of small molecule drugs and macromolecular therapeutics. Using three different cell systems, including primary human cells, we have studied the uptake, subcellular localisation and effect on cell viability of the well characterised octaarginine and the more recently discovered hydrophobic PFVYLI peptide, either alone, or conjugated to the proapoptotic domain peptide PAD (klaklak)(2). Octaarginine and PFVYLI were efficiently endocytosed into cells at 37 degrees C but an ability to translocate directly across the plasma membrane at higher peptide concentrations or when uptake experiments were performed on ice was confined to the cationic variant. Octaarginine- and PFVYLI-PAD conjugates were cytotoxic, with KG1a leukaemia cells being more sensitive than HeLa cells and octaarginine-PAD being the most potent conjugate in both cell lines. The effects of the CPP-PAD conjugates on cell morphology and permeability was rapid suggesting that cytotoxicity is partially mediated at the plasma membrane rather than exclusively through induction of apoptosis at the mitochondria. Primary human leukaemia cells were more similar to KG1a cells than HeLa cells, suggesting the relative sensitivity of leukaemia cells to these peptides could be exploited in vivo.

Evaluation and characteristics of "dropouts" in a longitudinal clinical study.

This paper attempts to identify characteristics of a longitudinal clinical study's "dropout" population (1974-1996) of patients using overdentures. This study included 395 subjects. Dropouts were identified as persons who did not respond to letters or telephone calls after participating in the study for up to 2 years, could not be located, or did not wish to return to the study. Participants (N=273) and Dropouts (N=84) were compared by evaluating a series of factors: sociodemographic, medical, health, and some oral health behaviors. The population was divided into two very similar cohorts for analysis based on years of recruitment: Group I (1974-1984) and Group II (1985-1993). Significant differences were found between them, including vision problems and risk of oral soft tissue problems related to medical diagnosis. Dropouts were significantly younger than Participants, had fewer hearing and vision problems, tended to brush their teeth more often and were more likely to use daily topical fluoride in their overdentures. The differences between the Dropouts and the Participants may be that younger persons are more mobile and have fewer vision and hearing problems, but this does not help predict their commitment to a study. Health behaviors such as brushing overdenture abutments or fluoride use may be more predictable but are harder to assess until persons have been study participants for some time.

Application of short-form oral health impact profile on elderly Japanese.

OBJECTIVES: The purpose of this study was to use the oral health impact profile (OHIP-14) to evaluate the impact of oral disease on the quality of life of a group of independently-living elderly persons in an urban area of Japan. SUBJECTS: A total of 1244 participants of the Senior Citizen's College, who attended the lectures once a week. They were community-dwelling, independently-living people over 60 years of age. MEASUREMENTS: Japanese version of the short-form OHIP-14. RESULTS: Internal reliability for the 14 items overall was very high (Cronbach's alpha = 0.95). Report of 'painful aching' and 'uncomfortable to eat' were the two most highly scored items using the mean sum OHIP-14 score. A multiple logistic regression analysis indicated that the sum OHIP-14 score had significant associations with self-assessment of general health, dental status, and a perceived need for dental treatment. However, age, gender, dissatisfaction with financial status or education level was not significantly associated with the sum OHIP-14. Compared with that of other countries, the items were ranked similarly, whereas the perceived magnitudes of the problems were quite different from other population. CONCLUSIONS: The OHIP-14 in Japanese had a high internal reliability, was significantly associated with dental status and comparable ranking for items when compared with studies from other countries.

In vitro evaluation of fluoride varnish on overdenture abutments.

STATEMENT OF PROBLEM: No clinical study has evaluated the efficacy of fluoride varnish as a topical fluoride agent for the protection of overdenture abutments from dental caries. PURPOSE: This study assessed the efficacy of a fluoride varnish in protecting overdenture abutments from demineralization in an in vitro environment. MATERIAL AND METHODS: Eighty caries-free, extracted teeth were sectioned and domed immediately below the cementoenamel junction, simulating overdenture abutment preparations. Acid resistant nail varnish was painted on all surfaces except for a window (1 x 4 mm) on the prepared occlusal dentin surfaces. Teeth were randomly divided into 4 groups of 20 specimens: control, washed with deionized/distilled water; Daily Gel, treated with Karigel-N (5,000 ppm) for 4 minutes daily; Weekly Gel, treated with Karigel-N for 4 minutes weekly; and Weekly Varnish, treated with Duraflor (22,600 ppm) weekly. The varnish was removed using a blade 24 hours after each application to simulate the clinical loss of the varnish. Teeth were then placed in a cycle of demineralization (2.2 mMol/L CaCl(2)2H(2)O, 2.2 mMol/L KH(2)PO(4), and 50 mMol/L acetic acid at pH 4.3) for 6 hours and remineralization (1.5 mMol/L CaCl(2)2H(2)O, 0.9 mMol/L KH(2)PO(4), and 150 mMol/L KCl at pH 7.0 for 17 hours) for 21 days. Half the teeth in each group were brushed with no dentifrice for 10 seconds, twice daily. Teeth were sectioned at 100 +/- 10 microm buccolingually and evaluated under polarized light microscopy and contact microradiography. The depth of each lesion and the width of the remineralization bands were measured (mm). Analysis of variance models and T-tests were used to assess the effects of different treatments (alpha=.05). Duncan multiple range tests were then chosen as post hoc tests to evaluate the statistical significance of all pairwise comparisons. RESULTS: The control group had the deepest lesions (mean depth 400 +/- 39 microm). The lesions from the varnish and daily gel groups were significantly shallower than the lesions in both the control group and the weekly gel group. The remineralization bands in the varnish group were 52% wider than the control group bands. However, the daily gel group had the largest increase in band width (117% increase) compared with the control group. There were significant differences between all groups for net depth (lesion depth minus the remineralization band) (P<.0001). Daily application of fluoride gel was significantly more effective than the other treatments tested. Brushing was not a significant factor. CONCLUSION: Within the limitations of this in vitro study, treatment of overdenture abutment with various topical fluorides significantly inhibited demineralization and enhanced remineralization of cut occlusal dentin surfaces. Daily use of Karigel-N was the most effective treatment, followed by the weekly application of Duraflor varnish.