Influence of the Use of Irrigation Solution Inhibitors in Improving Dentine Adhesion: A Systematic Review and Meta-Analysis.

INTRODUCTION: This systematic review examined the effect of neutralizing agents on bond strength after irrigation with sodium hypochlorite and their existing protocols in literature. METHODS: This present study adhered to the PRISMA guidelines and was registered at PROSPERO. Five electronic databases were searched (sept-2020/jan-2021) in English, Spanish, and Portuguese, without any restrictions on publication date. Cases reports, editorials and literature reviews were not included. The risk of bias was assessed using the Cochrane Collaboration tool. From the initial 7,147 studies, 2,745 were removed as duplicates and 4,382 were excluded after a title/abstract screen. RESULTS: Seventeen in vitro studies were included. The results showed that the higher the concentration of sodium hypochlorite, the lower the bond strength at dentine/restoration interface (p⟨0.01). Among the studies, sodium ascorbate was the most widely used neutralizer and showed the most significant results in increasing bond strength (p⟨0.01). The bond strength values were found to increase with longer application time of the neutralizing substances (p⟨0.01). CONCLUSIONS: The use of sodium ascorbate as a neutralizing agent can reverse the negative effects of the sodium hypochlorite and improve the bond strength between dentine and resin cement, however, it isn't possible to determine the best protocol for use.

Crown Reconstruction of Erosive Wear Using High-viscosity Glass Ionomer Cement: A Case Report.

The aim of this clinical report is to present a possible alternative treatment, with 24-month follow-up, for restoring tooth loss due to extensive erosive tooth wear. A 21-year-old male patient, complaining of intense sensitivity in the maxillary posterior teeth, and presenting severe wear on maxillary premolar and molar teeth due to gastroesophageal reflux, sought care in the university clinics. The planned treatment was to refer for medical treatment and perform restorations with the high-viscosity glass ionomer cement Equia Forte (GC Corporation, Tokyo, Japan), aiming to restore the dental anatomy and to consequently decrease the pain symptomatology. A silicone guide, obtained from a diagnostic waxing, was used during the restorative approach considering the patient's occlusion. After all the clinical steps of the restorative technique, an occlusal adjustment of restorations was performed. During monthly recalls up to 24 months, the treatment was stable and in service. In addition, the patient reported no pain and improved chewing, leading to a better quality of life.

Perceptibility and Acceptability of Surface Gloss Variation Under Different Illuminants.

OBJECTIVE: The purpose of this study was to evaluate the influence of different illuminants on the perceptibility and acceptability of surface gloss variations and to determine limiting values. METHODS: Eight composite resin specimens and one human tooth specimen were polished to obtain composite resin specimens with different gloss units (GU) of 10, 20, 30, 40, 50, 60, 70, and 80 and a human tooth specimen of 80 GU. Sixty observers compared the surface gloss of the specimens in a light booth. For perceptibility testing, the specimens were randomly positioned two at a time. The acceptability of the gloss variation was determined by comparing the composite resin specimens with the tooth specimen. The observers answered specific questions to determine the level and perceptibility and acceptability limits of gloss variations. All analysis was done with two illuminants (D65 and fluorescent light) used randomly. Data were submitted to a nonlinear probit model and nonlinear probit regression estimation (α=0.05). RESULTS: Significant differences in illuminants were observed for perceptibility (p<0.001) and acceptability (p=0.045). The perceptibility limit for D65 was 7.0 GU and 6.8 GU for fluorescent illuminant. The acceptability limit for D65 was 34.2 GU and 37.1 GU for fluorescent illuminant. CONCLUSIONS: More accurate perceptibility and acceptability judgments of the surface gloss of composite resin were made when the specimens were illuminated with D65 light.

The Evaluation of Different Treatments of Incipient Caries Lesions: An in Situ Study of Progression Using Fluorescence-based Methods.

CLINICAL RELEVANCE: Effective methods to control incipient caries lesions are needed. In this investigation, several methods provide encouraging results. SUMMARY: This study aimed to evaluate in situ the inhibition of incipient caries lesion progression using different treatment protocols and to evaluate the effectiveness of fluorescence-based methods (DIAGNOdent, DIAGNOdent pen, and VistaProof fluorescence camera [FC]) in monitoring this process. The research was conducted in four phases: (1) at baseline, (2) after a first cariogenic challenge, (3) after treatment modalities, and (4) after a second cariogenic challenge. Sixteen volunteers used intraoral acrylic palatal appliances, each containing six enamel blocks (n=96). The cariogenic challenge was performed using a 20% sucrose solution over a 14-day period. The appliances were removed eight times a day and, upon removal, two drops of the solution were placed onto each enamel block. The enamel blocks were randomly assigned to three treatment groups: fluoride varnish ([FV] Duraphat; n=32), resin infiltrant ([RI] Icon; n=32), and adhesive system ([AS] Scotchbond; n=32). At the end of each phase, the surface microhardness (SMH) was measured, and two trained examiners evaluated the specimens using fluorescence-based methods. In addition, integrated mineral loss (ΔΔZ; vol%.min x µm) and lesion depth (ΔLD; µm) were evaluated using transverse microradiography. A two-way analysis of variance and a Tukey post hoc test were calculated (α=5%). Significant differences in SMH were observed according to the treatment, phases, and interaction of factors (p<0.001). Treatment with FV resulted in significantly higher SMH values in phases 3 and 4 compared to RI and AS, with the last two treatments resulting in similar values (p>0.05). The ΔΔZ value was similar for FV and AS but significantly higher for RI (p=0.016). ΔLD was not significantly different among the groups (p=0.126). Significant differences in the measurement of fluorescence for each fluorescence-based method were observed between each phase of the study (p<0.05). It can be concluded that all treatments were effective in inhibiting the in situ progression of incipient lesions, although to different degrees, with minor mineral loss changes observed for the AS and FV. Besides, all fluorescence-based methods tested, except for that using the FC device, were effective in monitoring caries lesion progression.

Do Tooth- and Cavity-related Aspects of Noncarious Cervical Lesions Affect the Retention of Resin Composite Restorations in Adults? A Systematic Review and Meta-analysis.

PURPOSE: The purpose was to perform a systematic review and meta-analysis based on the following research question: do tooth- and cavity-related aspects of noncarious cervical lesions (NCCLs) affect the retention of composite restorations? METHODS: Randomized clinical trials (RCTs) that evaluated the retention rate of resin restorations in NCCLs were included for the identification and comparison of their characteristics. The search was conducted in PubMed and adapted for Scopus, Web of Science, Latin American and Caribbean Health Sciences Literature database (LILACS), Brazilian Library in Dentistry (BBO), Cochrane Library, and System for Information on Grey Literature in Europe (SIGLE) without restrictions until July 2018. Unpublished and ongoing trial registries were also searched. The Cochrane Collaboration tool was used for assessing risk of bias. The quality of the evidence was graded using the Grading of Recommendations: Assessment, Development and Evaluation. Using the random effects model, a meta-analysis was conducted for each aspect (arch distribution, tooth location, wear facets, dentin sclerosis, shape, size, depth, occluso-gingival distance, and margin location). RESULTS: We retrieved 6738 articles. After removal of duplicates and nonrelevant articles, 24 RCTs remained. The anterior tooth location favored the retention rates of restoration of NCCLs (relative risk [RR], 1.08; 95% confidence interval [CI], 1.00-1.16). The presence of wear facets is a risk factor for the retention of restorations (RR, 0.91; 95% CI, 0.83-0.99). The evidence was moderate for arch distribution and low or very low for all other factors because of heterogeneity, imprecision, and inconsistency. CONCLUSION: The tooth location and the presence of wear facets can affect the retention of composite resins in NCCLs.

Clinical Evaluation of Noncarious Cervical Lesions of Different Extensions Restored With Bulk-fill or Conventional Resin Composite: Preliminary Results of a Randomized Clinical Trial.

PURPOSE: This randomized clinical trial evaluated the influence of the occlusogingival distance (OGD) of noncarious cervical lesions (NCCLs) on the clinical performance of a regular bulk-fill resin composite and a regular nanofilled resin composite. METHODS AND MATERIALS: A total of 140 restorations were randomly placed in 77 participants by one operator. NCCLs were divided into four groups (n=35) according to OGD (1.5 mm±10% or 3 mm±10%) and resin composites (Filtek Bulk Fill Posterior [B] or Filtek Z350 XT [C]) used: 1.5 mm-B, 1.5 mm-C, 3 mm-B, and 3 mm-C. A two-step self-etch adhesive (Clearfil SE Bond) was applied following manufacturer instructions in all restorative procedures. Restorations were polished 1 week after placement. Clinical evaluation was performed at baseline (7 days), 6 months, and 1 year by two calibrated examiners, according to the modified US Public Health Service criteria evaluating fractures/retention, marginal staining, marginal adaptation, recurrence of caries, anatomic form, postoperative sensitivity, and surface texture. The Kruskal-Wallis test was used for intergroup comparison in each follow-up; the Friedman analysis of variance, followed by the least significant difference test (multiple comparisons) was used for intragroup comparison between baseline and follow-up times (α=0.05). RESULTS: Two restorations were lost at 12 months (1 for 1.5 mm-B and 1 for 3 mm-B). The retention rates at 12 months were 100% for 1.5 mm-C, 97% for 1.5 mm-B, 100% for 3 mm-C; and 97% for 3 mm-B, with no statistical difference among the groups (p=0.570). At 12 months, a statistically significant difference was found among the follow-up times for the same group (1.5 mm-B, 1.5 mm-C, and 3 mm-B) regarding the marginal staining criterion; moreover, the 3 mm-C group showed a significant difference from 6 months. No significant difference was found for the other parameters. CONCLUSION: Both resin composites showed acceptable clinical performance, and the OGD of NCCLs did not influence the clinical performance of resin composite restorations after 12 months.

Perceptibility and Acceptability of Surface Gloss Variations in Dentistry.

OBJECTIVE: To assess the visual perception of observers regarding perceptibility and acceptability of surface gloss variations of resin composites and to determine the limit of perceptibility and acceptability of gloss variations. METHODS: Eight resin composite specimens and one human tooth specimen were fabricated. The resin specimens were polished to reach a surface gloss, in gloss units (GUs), of 10 GU, 20 GU, 30 GU, 40 GU, 50 GU, 60 GU, 70 GU, and 80 GU, and the human tooth specimen had a surface gloss of 80 GU. Sixty observers were selected to compare the surface gloss of the specimens in a light booth. For the perceptibility assessment, specimens were randomly displayed two at a time. Each observer performed a total of 144 observations. Observers answered two specific questions for determining the level and limit of perceptibility of gloss variations. The acceptability limit of gloss was determined by comparing the resin specimens with the tooth specimen. The observations were performed with dental practice scenarios (illuminant conditions, visualization field, and observers' education). Data were submitted to a nonlinear probit model and nonlinear regression estimation probit (5%). RESULTS: Differences in perceptibility and acceptability were observed for surface gloss variations (ΔGU) (p<0.001). Perceptibility increased with ΔGU (10<20<30<40<50=60=70), while acceptability decreased with ΔGU (0=10>20>30>40>50>60=70). Acceptability and perceptibility limits were 6.4 GU and 35.7 GU, respectively. CONCLUSIONS: Perceptibility and acceptability of surface gloss are influenced by gloss variations. A variation of 6.4 GU was required for 50% of observers to notice gloss variations. Concerning acceptability, observers required a variation of 35.7 GU to consider differences in gloss not acceptable.

Influence of protease inhibitors on the degradation of sound, sclerotic and caries-affected demineralized dentin.

The aim of this study was to evaluate influence of protease inhibitors on degradation of sound, sclerotic and caries-affected dentin. Thirty-nine molars were used, thirteen for each dentin condition. Three slices were obtained from each tooth, each one immersed in the following different solutions for 1 h: 1) artificial saliva; 2) 2% chlorhexidine; 3) 0.5% epigallocatechin-gallate (EGCG). After immersion, samples were subjected to enzymatic degradation challenge (collagenase from Clostridium histolyticum). Nanohardness (HIT) and elastic modulus (Er) were measured before and after enzymatic challenge, as well as the ultimate tensile strength (UTS). Results of UTS, HIT and Er tests were submitted to repeated measurements ANOVA and Tukey post-test (α = 0.05). Higher values of UTS were found for sound dentin in control (40.30 ±â€¯21.38 MPa) and 0.5% EGCG (30.05 ±â€¯19.67 MPa) groups. Before degradation, higher values of HIT (0.237 ±â€¯0.062 GPa) and Er (5.58 ±â€¯1.75 GPa) were found for 0.5% EGCG group in caries-affected dentin. After degradation, 2% chlorhexidine group had higher values of HIT and Er for sound (0.134 ±â€¯0.020 GPa and 3.57 ±â€¯0.40 GPa) and sclerotic (0.201 ±â€¯0.048 GPa and 4.30 ±â€¯0.56 GPa) dentin. The 2% chlorhexidine showed best effect increasing HIT and Er, mainly for sclerotic dentin, before/after enzymatic degradation. The 0.5% EGCG showed better effect on HIT and Er in caries-affected dentin, before enzymatic degradation.

Bonding Performance of Simplified Adhesive Systems in Noncarious Cervical Lesions at 2-year Follow-up: A Double-blind Randomized Clinical Trial.

OBJECTIVES: This study aimed to evaluate the bonding performance of a universal adhesive used according to self-etching or etch-and-rinse protocols in noncarious cervical lesions (NCCLs) and to compare the two protocols with their respective gold standard techniques. METHODS AND MATERIALS: This randomized, double-blind clinical study enrolled 34 participants who met the inclusion criteria, 29 of whom returned after two years. They received 152 restorations bonded with one of the three adhesives (Scotchbond Universal Adhesive, Adper Single Bond 2, or Clearfil SE Bond) and one of the two bonding techniques tested. The NCCLs were restored with nanocomposite resin (Filtek Supreme). Final contours were done with a fine diamond rotary instrument and polished with rubber points. The restorations were evaluated using the FDI World Dental Federation criteria at baseline (seven days after the restoration procedure), 6, 12, and 24 months. Descriptive statistics, Kruskal-Wallis, Friedman analysis of variance, and least significant difference tests were performed. RESULTS: No statistically significant differences were found in esthetics or the functional and biological evaluated criteria among the adhesive systems and techniques. CONCLUSIONS: The Scotchbond Universal system behaved similarly to the conventional etch-and-rinse or self-etching systems in all the adhesion strategies in the evaluated periods.

Color Stability of Resin Cements Exposed to Aging.

The aim of this study was to evaluate the color stability of light-cured and dual-cured resin cements after artificial accelerated aging. Ten specimens (6-mm diameter and 2-mm thickness) for each of five resin cements were prepared: GC (dual-cured cement, GCem), Vb (light-cured cement, Variolink II only the base), Vbc (dual-cured cement, Variolink II base with catalyst), VV (light-cured cement, Variolink Veneer), and FR (flowable resin composite, light cured). The samples were polished and stored in an accelerated artificial aging machine for 308 hours (160 klx), with cycles of 120 minutes under light and 60 minutes in the dark. All aging was carried out in distilled water at 37°C and light irradiation at 765 W/m2. The samples were evaluated in a spectrophotometer before and after aging, and results were calculated according to CIEDE2000. The data were statistically analyzed (one-way analysis of variance and Tukey test, 95% confidence). The results of ΔE00 were statistically significant for the type of cement (p<0.001), with differences among tested groups. Variolink II (base only and base + catalyst) and the flowable resin were the cements with the lowest color variations after the artificial accelerated aging. Considering the values ΔE00 of acceptability and perceptibility, none of the tested cements showed acceptable values.

Whitening Efficacy of Whitening Mouth Rinses Used Alone or in Conjunction With Carbamide Peroxide Home Whitening.

OBJECTIVES: The aim of this study was to compare the effectiveness of whitening mouth rinses on teeth previously whitened or not, exposed to food dyes. METHODS AND MATERIALS: One hundred twenty enamel-dentin specimens, 3 mm in diameter, were obtained from bovine incisors. The specimens were stained for 14 days in staining broth. After staining, the initial color reading was performed via a spectrophotometer CM-2600d (Konica Minolta). Half of specimens were submitted to whitening (10% carbamide peroxide [CP]) for 14 days. They were then divided into three groups and were submitted to cycles of staining (five minutes) and mouth rinses (two minutes) for 12 weeks, with the following: CP-LI, Listerine Whitening; CP-PL, Plax Whitening; CP-BP, bromelain + papain; CP-DW, deionized water. LI, PL, BP, and DW groups were submitted to the same cited cycles but with no prior bleaching. The color measurements were performed after four, eight, and 12 weeks of treatment with mouth rinses. Data were submitted to repeated measures analysis of variance (ANOVA) and Tukey's test for multiple comparisons, with significance level at 5%. RESULTS: The results showed that the CP-LI, CP-PL, LI, and PL groups had greater color change than did the others. The CP-BP and BP groups were similar to CP-DW and DW. CONCLUSIONS: We therefore conclude that Listerine Whitening mouth rinse presented the highest bleaching effect, followed by Plax Whitening mouth rinse. Both maintained CP bleaching effect after 12 weeks of dye-rinse cycles. However, none of these rinses were able to produce whitening similar to CP. Bromelain- and papain-containing mouth rinses did not show bleaching effect, being similar to the control groups.

Treatment with icatibant in the management of drug induced angioedema.

Acute, drug-induced angioedema may not respond to standard therapies, because the pathogenetic mechanism that induces the pathology is not always mediated by histamine but, in certain instances, by bradykinin. A case of angioedema is reported here, in which allergic etiology was excluded by the non-response to antihistamines. Considering the clinical history (repeated use of drugs) and the ineffectiveness of standard therapy, it was decided to administer a beta2 receptor antagonist, icatibant. After 20 minutes, the patient reported a subjective improvement. The only form of angioedema for which this type of medication is licensed is the hereditary deficiency of C1 inhibitor. The use of icatibant for the treatment of other types of angioedema (which can also be life-saving if the airway is involved) is off label. The off-label use of a drug is allowed in the absence of a viable alternative therapy, if there is scientific evidence in the literature and if the prescriber takes responsibility. The case here reported draws attention to this therapeutic problem and underlines the fact that a life-threatening emergency can justify the use of icatibant.

Seven-year clinical performance of resin composite versus resin-modified glass ionomer restorations in noncarious cervical lesions.

PURPOSE: The purpose of this study was to comparatively assess the seven-year clinical performance of a one-bottle etch-and-rinse adhesive with resin composite (RC) and resin-modified glass ionomer (RMGI) restorations in noncarious cervical lesions. METHODS AND MATERIALS: One operator placed 70 restorations (35 restorations in each group) in 30 patients under rubber dam isolation without mechanical preparation. The restorations were directly assessed by two independent examiners, using modified US Public Health Service criteria at baseline and 6, 12, 24, 60, and 84 months. The obtained data were tabulated and statistically analyzed using the Fisher and McNemar tests. A difference was significant if p<0.05. RESULTS: Twenty patients were available for recall after seven years (66.6%), and 25 RC and 26 RMGI restorations out of 70 restorations were evaluated. Excellent agreement was registered for all criteria between examiners (κ≥0.85). Alfa and bravo scores were classified as clinically acceptable. The McNemar test detected significant differences within RC restorations between baseline and seven-year evaluations for anatomic form, marginal integrity, and retention (p<0.05). For RMGI restorations, a significant difference was identified for marginal integrity (p<0.05). As to material comparison, the Fisher exact showed a better retention performance for RMGI restorations than for RC restorations (p<0.05). Twelve composite restorations were dislodged (52.0% retention) and three ionomer restorations were lost (88.5% retention). The cumulative success rate for RC and RMGI was 30% and 58.1%, respectively. CONCLUSIONS: After seven years of service, the clinical performance of RMGI restorations was superior to that of the adhesive system/resin composite restorations in this study.

Biophysical characterization of a binding site for TLQP-21, a naturally occurring peptide which induces resistance to obesity.

Recently, we demonstrated that TLQP-21 triggers lipolysis and induces resistance to obesity by reducing fat accumulation [1]. TLQP-21 is a 21 amino acid peptide cleavage product of the neuroprotein VGF and was first identified in rat brain. Although TLQP-21 biological activity and its molecular signaling is under active investigation, a receptor for TLQP-21 has not yet been characterized. We now demonstrate that TLQP-21 stimulates intracellular calcium mobilization in CHO cells. Furthermore, using Atomic Force Microscopy (AFM), we also provide evidence of TLQP-21 binding-site characteristics in CHO cells. AFM was used in force mapping mode equipped with a cantilever suitably functionalized with TLQP-21. Attraction of this functionalized probe to the cell surface was specific and consistent with the biological activity of TLQP-21; by contrast, there was no attraction of a probe functionalized with biologically inactive analogues. We detected interaction of the peptide with the binding-site by scanning the cell surface with the cantilever tip. The attractive force between TLQP-21 and its binding site was measured, statistically analyzed and quantified at approximately 40 pN on average, indicating a single class of binding sites. Furthermore we observed that the distribution of these binding sites on the surface was relatively uniform.

Chronic systemic inflammatory syndrome in patients with AECOPD presenting to emergency department.

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is the fourth cause of dead in the world. Because of high incidence of comorbidities in COPD patients, it has been proposed a new hypothesis that inscribe this disease in a complex contest named chronic systemic inflammatory syndrome (CSIS). Either COPD and the most common comorbidities responsible for its clinical and natural history, like hypertension, diabetes, coronary artery disease, heart failure, recognize a pro-inflammatory state, marked, for example, by elevated C reactive protein (CRP). METHODS: 113 consecutive patients presenting to emergency department (ED) with acute exacerbated COPD were enrolled. They underwent to full medical history and physical examination. CRP was measured at ED arrival, discharge and at 1-6-12 month follow up. CSIS was diagnosed according to specified criteria. RESULTS: CSIS was diagnosed in 84% patients. CRP was maximally increased at admission during the exacerbation, but didn't correlate with the severity of it. At discharge, CRP values were lowest; during follow up, CRP demonstrated a chaotic behavior growing up till 6 month without any correlation with new exacerbation events. At 1 year it decreased, never reaching normal values in the majority of our patients thus confirming the presence of a persistent inflammation in COPD. CONCLUSIONS: CSIS was diagnosed in 84% of our population demonstrating that COPD patients need to be approached in a multidisciplinary way.

Influence of hydrogen peroxide bleaching gels on color, opacity, and fluorescence of composite resins.

The aim of the present study was to evaluate the effect of 20% and 35% hydrogen peroxide bleaching gels on the color, opacity, and fluorescence of composite resins. Seven composite resin brands were tested and 30 specimens, 3-mm in diameter and 2-mm thick, of each material were fabricated, for a total of 210 specimens. The specimens of each tested material were divided into three subgroups (n=10) according to the bleaching therapy tested: 20% hydrogen peroxide gel, 35% hydroxide peroxide gel, and the control group. The baseline color, opacity, and fluorescence were assessed by spectrophotometry. Four 30-minute bleaching gel applications, two hours in total, were performed. The control group did not receive bleaching treatment and was stored in deionized water. Final assessments were performed, and data were analyzed by two-way analysis of variance and Tukey tests (p<0.05). Color changes were significant for different tested bleaching therapies (p<0.0001), with the greatest color change observed for 35% hydrogen peroxide gel. No difference in opacity was detected for all analyzed parameters. Fluorescence changes were influenced by composite resin brand (p<0.0001) and bleaching therapy (p=0.0016) used. No significant differences in fluorescence between different bleaching gel concentrations were detected by Tukey test. The greatest fluorescence alteration was detected on the brand Z350. It was concluded that 35% hydrogen peroxide bleaching gel generated the greatest color change among all evaluated materials. No statistical opacity changes were detected for all tested variables, and significant fluorescence changes were dependent on the material and bleaching therapy, regardless of the gel concentration.

In vivo acid etching effect on bacteria within caries-affected dentin.

Acid etching procedures may disrupt residual bacteria and contribute to the success of incomplete caries removal followed by adhesive restoration. This study evaluated the in vivo effect of acid etching on cariogenic bacterial activity within affected dentin after minimally invasive treatment of caries lesions. Twenty-eight carious permanent teeth received standardized selective caries removal and random acid etch treatment (E) or not (NE) prior to adhesive restoration. Baseline and 3-month dentin biopsies were collected. The number of bacteria and activity of total bacterial cells and Streptococcus mutans were determined by quantitative PCR and RT-PCR. No statistically significant differences were observed in total bacterial number and activity between E and NE treatments (p > 0.3008). For NE, however, the residual S. mutans bacterial cells were reduced (p = 0.0027), while the activity per cell was significantly increased (p = 0.0010) after reentry at 3 months after restoration. This effect was not observed in group E. Although no significant differences were found between groups, this study suggests that acid etching of affected dentin prior to adhesive restoration may directly or indirectly have an inhibitive effect on the activity of residual cariogenic bacteria. Further research is required to investigate this potential effect.

In vivo dentin microhardness beneath a calcium-phosphate cement.

A minimally invasive caries-removal technique preserves potentially repairable, caries-affected dentin. Mineral-releasing cements may promote remineralization of soft residual dentin. This study evaluated the in vivo remineralization capacity of resin-based calcium-phosphate cement (Ca-PO(4)) used for indirect pulp-capping. Permanent carious and sound teeth indicated for extraction were excavated and restored either with or without the Ca-PO(4) base (control), followed by adhesive restoration. Study teeth were extracted after 3 months, followed by sectioning and in vitro microhardness analysis of the cavity floor to 115-microm depth. Caries-affected dentin that received acid conditioning prior to Ca-PO(4) basing showed significantly increased Knoop hardness near the cavity floor. The non-etched group presented results similar to those of the non-treated group. Acid etching prior to cement application increased microhardness of residual dentin near the interface after 3 months in situ.

In vivo dentin remineralization by calcium-phosphate cement.

Minimally invasive caries-removal procedures remove only caries-infected dentin and preserve caries-affected dentin that becomes remineralized. Dental cements containing calcium phosphate promote remineralization. This study evaluated the in vivo remineralization capacity of resin-based calcium-phosphate cement (Ca-P) used for indirect pulp-capping. Carious and sound teeth indicated for extraction were randomly restored with the Ca-P base or without base (control), followed by adhesive restoration. Study teeth were extracted after three months, followed by elemental analysis of the cavity floor. Mineral content of affected or sound dentin at the cavity floor was quantified by electron probe micro-analysis to 100-mum depth. After three months, caries-affected dentin underneath the Ca-P base showed significantly increased calcium and phosphorus content to a depth of 30 mum. Mineral content of treated caries-affected dentin was in the range of healthy dentin, revealing the capacity of Ca-P base to promote remineralization of caries-affected dentin.

Ghrelin control of GH secretion and feeding behaviour: the role of the GHS-R1a receptor studied in vivo and in vitro using novel non-peptide ligands.

Energy homeostasis is controlled by a complex regulatory system of molecules that affect food intake and that are critical for maintaining a stable body weight during life. Ghrelin is a peptide of 28 amino acid synthesized predominantly by the stomach and the gut, which activate the type 1a growth hormone (GH) secretagogue receptor (GHS-R1a), a G-protein coupled receptor. The acylated form of ghrelin potently stimulates GH secretion both in vitro and in vivo in several animal species, including humans. Beside the endocrine effect, ghrelin shows also extraendocrine activities, including stimulation of feeding behaviour. Several classes of small synthetic peptide and non-peptide ligands of the GHS-R1a have been described and are able to release GH and stimulate food intake. However, in time, it appeared that the stimulating effects on GH secretion could be divorced from those on food intake, suggesting that more than a single receptor might be involved. Several experimental data have even questioned the physiological role of ghrelin in the control of GH secretion and energy metabolism. By using novel agonists, partial agonists, and antagonists for the GHS-R1a receptor, we have studied whether the stimulation of this receptor could account for the purported physiological role of ghrelin. Our results demonstrate that the ability to bind in vitro the GHS-R1a is not predictive of the in vivo biological activity of the compounds and that the endocrine and extraendocrine effects could be mediated also by receptors different from the GHS-R1a.