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Purpose: Third molar agenesis (TMA) is the most common craniofacial anomaly and has been associated with craniofacial patterns in different populations. Therefore, the aim of this retrospective cross-sectional study was to assess a possible association between craniofacial patterns and TMA in German orthodontic patients., Methods: Patients undergoing orthodontic treatment with dental records including anamnesis, pretreatment lateral cephalograms and orthopantomograms were evaluated. Cephalometric analyses were conducted digitally and lines, angles and proportions were measured to investigate craniofacial morphology. Skeletal classes were determined by the individualised Wits appraisal and ANB angle. The TMA was identified with the help of orthopantomograms. Patients showing agenesis of at least one third molar were included in the TMA group. Statistical analysis was performed to assess the association between TMA and craniofacial patterns (α of p ≤ 0.05)., Results: A total of 148 patients were included, 40 (27.0%) presented at least one missing tooth (TMA group) and 108 (73.0%) showed full dentition (control group). Skeletal class determined by the individualised Wits appraisal revealed statistical significance between the TMA and control groups (p = 0.022), in which TMA patients were 11 times more likely to present with an individualised skeletal class III (odds ratio 11.3, 95% confidence interval 1.7-139.5). Skeletal cephalometric analysis revealed no statistical differences between TMA and control groups for any further angular, linear and proportional parameters., Conclusion: Third molar agenesis was associated with skeletal class III determined by the individualised Wits appraisal., (© 2023. The Author(s).)

This study aimed to evaluate the influence of the Er,Cr:YSGG irradiation and 980-nm diode lasers on the surface roughness (SR) and volume loss (VL) of dentin subjected to cariogenic challenge. Subsequently, 130 specimens of bovine dentin were divided into the following 13 groups: NT: no treatment; FG: fluoride gel; FV: fluoride varnish; Di: 980-nm diode; Di + FG; Di + FV; FG + D; FV + Di; Er: Er,Cr:YSGG; Er + FG; Er + FV; FG + Er and FV + Er. Er,Cr:YSGG laser parameters were as follows: 0.25 W; 5.0 Hz; 4.46 J/cm2 without water and 55% air. Furthermore, the 980-nm diode laser parameters were 2.0 W; 2.0 Hz; 21.41 J/cm2. The samples from each group were subjected to pH cycling. A confocal laser scanning microscope was used to evaluate SR and VL. Difference between the volume of the reference and treated areas + DES/RE was used to determine SR and VL. The mean values of the different groups were subjected to analysis of variance and Tukey's post-hoc test. The VL values were analyzed using the Kruskal-Wallis and Dunn post-hoc test (p < 0.05). The SR of the reference area did not show a statistically significant 1807-3107-bor-38-e025treatment and cariogenic challenge (p > 0.05). Moreover, VL in the FV + Di and FV + Er groups showed a statistically significant difference compared with areas submitted to different types of treatment and cariogenic challenge (p > 0.05). Er,Cr:YSGG and 980-nm diode lasers associated with fluoride varnishes decreased dentin VL in bovine teeth submitted to cariogenic challenge.

This cross-sectional study aimed to investigate the association between developmental defects of enamel (DDE) and single nucleotide polymorphisms (SNPs) in the genes encoding the vitamin D receptor (VDR) and parathyroid hormone (PTH). Orthodontic patients receiving treatment at a dental school were selected through convenience sampling. Intra-oral photographs were used to assess DDE, which were classified according to the criteria proposed by Ghanim et al. (2015) by a single calibrated examiner (Kappa>0.80). Enamel hypoplasia, molar-incisor hypomineralization (MIH), hypomimineralized second primary molar (HSPM), and non-MIH/HSPM demarcated opacities were considered for the analysis. Genomic DNA was extracted from buccal cells. The SNPs in VDR (rs7975232) and PHT (rs694, rs6256, and rs307247) were genotyped using real-time polymerase chain reactions (PCR). Statistical analyses were performed using the PLINK software (version 1.03, designed by Shaun Purcell, EUA). Chi-square or Fisher's exact tests were performed at a significance level of 5%. Ninety-one (n=91) patients (49 females and 42 males) (mean age of 14.1±5.8 years) were included. The frequency of DDE was 38.5% (35 patients). Genotype distributions were in Hardy-Weinberg equilibrium. No significant statistical association was found between DDE and the SNPs evaluated. A borderline association (p=0.09) was observed between DDE and the CC haplotype for SNP rs7975232 in VDR. In conclusion, the selected SNPs in VDR and PTH genes were not associated with DDE in the studied samples.

Background: The present study aimed to assess the frequency and variation of 13 nonmetric dental crown traits (NDCT) in permanent and primary molars in German orthodontic patients., Methods: Dental records from orthodontic patients were screened and evaluated. First and second permanent and primary upper and lower molars (from left and right sides) were assessed. Teeth with cavitated dental caries, occlusal wear, restorations and obvious dental deformities were not evaluated. The NDCT for permanent molars were identified and scored according to the odontoscopic system developed by Arizona State University Dental Anthropology System (ASUDAS). The NDCT for primary molars were identified and scored according to ASUDAS, Hanihara's method and Sciulli's method. The χ 2 test was used to investigate side preference and sexual dimorphism at a significance level of p ≤ 0.050., Results: A total of 163 orthodontic patients (82 males and 81 females) aged 8-14 years were included. A sexual dimorphism was observed for the hypocone in first upper permanent molar (p = 0.041). The protostylid was observed in lower permanent molars (range 2.1-10%). Males presented more hypoconulid than females (p = 0.019). Only females presented the distal trigonid crest in lower first permanent molars (p = 0.002). The most common groove pattern in primary molars was Y; male presented more Y grade than females in the lower second primary molar (p = 0.039). Asymmetry was observed in some traits, ranging from 0 to 100%., Conclusion: The present study showed the frequency of NDCT of molars in German orthodontic patients and demonstrated that some traits present sexual dimorphism., (© 2024. The Author(s).)

Purpose: To evaluate the antimicrobial activity of dentifrices based on Malva sylvestris and propolis and the effect on the acrylic resin., Methods: The inhibitory effect against Candida albicans, Enterococcus faecalis and Streptococcus mutans was determined. The specimens of resin were divided into groups: Control (brushing with distilled water); brushing with Colgate; brushing with Protex; brushing with Malvatricin, brushing with Proporalcare Dental Gel and brushing with Green Propolis Dental Gel. Brushing was carried out in a brushing machine. Roughness and color were assessed. The data were analyzed by ANOVA, followed by the Bonferroni post test (α= 0.05)., Results: The products evaluated showed antimicrobial activity against all microorganisms (P< 0.05), except Proporalcare Dental Gel, which was not effective against E. faecalis. Greater roughness (P< 0.05) was observed in the samples treated with Colgate. The samples from control and Protex groups showed the lowest color variation and the highest luminosity, with a difference in relation to the others (P< 0.05), which showed higher values, although clinically acceptable., Clinical Significance: The dentifrices based on natural products can be indicated for cleaning prostheses, since they showed antimicrobial activity and did not cause perceptible color changes of the resin tested. The dentifrices did not produce adverse effects on the surface of the resin or did so less than the conventional dentifrice., Competing Interests: The authors declared no conflict of interest. This study was funded in part by the Higher Education Personnel Improvement Coordination - Brazil (CAPES) - Financial Code 001 and the Institutional Research Support Program (PAPE-UNIUBE)., (Copyright©American Journal of Dentistry.)

To evaluate differences in the morphology of the frontal sinus in adolescents and adults with different craniofacial patterns, searches up to April 2024 were conducted in six databases and other information sources to identify observational studies. Study selection, data extraction, and quality assessment using the NOS scale were performed independently by two reviewers. Random effects meta-analyses were conducted to estimate the difference in frontal sinus measurements between different craniofacial skeletal patterns (α = 0.05). The certainty of the evidence was evaluated according to GRADE. Fourteen studies were included in the review. All studies had methodological limitations that affected their quality. The syntheses showed that skeletal Class II subjects presented a significantly smaller width of the frontal sinus than skeletal Class I subjects (MD = 0.56; 95% CI: 0.38, 0.74; p < 0.0001; I 2 = 3%). Skeletal Class III subjects showed a frontal sinus width (MD = -0.91; 95% CI: -1.35, -0.47; p < 0.0001; I 2 = 36%) and area (MD = -28.13; 95% CI: -49.03, -7.23; p = 0.0084; I 2 = 66%) significantly larger than those of the skeletal Class I subjects. The available evidence suggests a positive relationship between mandibular and frontal sinus size. There is limited evidence to make reliable estimates of the association of other craniofacial patterns and frontal sinus characteristics. These reported results are not conclusive and should be evaluated carefully due to the very low certainty of the evidence. The current evidence is scarce and consists of studies with methodological limitations; the results of the studies are often inconsistent, and the pooled estimates are imprecise. New high-quality research is still necessary., Competing Interests: The authors declare no conflicts of interest.

Background: This study aimed to evaluate the prevalence of retained primary teeth (RPT) associated with delayed permanent tooth eruption and the factors associated with this condition in German children., Methods: This is a cross-sectional retrospective study that evaluated panoramic radiographs from orthodontic patients. The diagnosis of RPT was established according to Nolla developmental stage. The primary tooth was considered retained when its successor permanent tooth was in Nolla stage 8, 9, or 10. Statistical analysis was performed with an α of 5% (p < 0.05)., Results: A total of 102 children (48 girls and 54 boys), and 574 primary teeth and their respective permanent successor teeth were evaluated. We classified 192 teeth as RPT. Sixty-one (59.8%) children presented one or more RPT. Gender was not significantly different between RPT and control teeth (p = 0.838; odds ratio 0.95, confidence interval 95% 0.44-2.16). In the majority of the RPT cases (68.7%), no clear cause to explain the prolonged retention was identified. The pathological problems most commonly observed with RPT were dental fillings (19.3%), followed by dental caries (4.6%), and ectopic tooth eruption (2.1%)., Conclusions: The incidence of RPT associated with delayed permanent tooth eruption in German children was high and the most common pathological condition associated with RPT was dental caries., (© 2023. The Author(s), under exclusive licence to Springer Medizin Verlag GmbH, ein Teil von Springer Nature.)

Background: The aim of this study was to determine if there is a correlation between fluoride release, surface hardness, and diametral tensile strength of restorative glass ionomer cements (GICs)., Material and Methods: Conventional (Riva Self Cure) and resin-modified (Riva Light Cure) GICs were used. Thirty-four samples (ø 6 x 3 mm) were prepared for each cement. The kinetics of fluoride release (n=4) was evaluated over 28 days using a fluoride-selective electrode (ISE 4010-C00). The analysis of surface hardness (n=10) was performed using a microhardness tester (Shimadzu HMV-2000, Japan) with a Knoop indenter and a load of 25 gf for 30 seconds. The diametral tensile strength test (n=10) was conducted on a universal testing machine at a speed of 0.75 mm/min. Fluoride release data were analyzed by two-way repeated measures ANOVA and Bonferroni post hoc test, while independent t-test was used for other analyses (α=0.05)., Results: Overall, the groups showed higher fluoride release until day 7 and a progressive decrease until day 28. On day 1 and day 21, Riva Self Cure showed a higher level of release than Riva Light Cure ( p =0.026). Riva Light Cure showed higher diametral tensile strength ( p <0.0001) and surface hardness ( p =0.034) than Riva Self Cure. A negative correlation was found, indicating that higher fluoride release is associated with lower surface hardness and diametral tensile strength., Conclusion: Fluoride release and mechanical performance are related properties of GICs, and these properties exhibit different values depending on the type of material. Resin-modified GIC release less fluoride but exhibit better mechanical performance compared to conventional GIC. Key words: Diametral Tensile Strength, Fluoride, Glass Ionomer Cement, Surface Hardness., Competing Interests: The authors declare no conflict of interest., (Copyright: © 2024 Medicina Oral S.L.)

Background: The objective this study was to evaluate the influence of preventive remineralizing techniques on surface roughness and volume loss of dentin submitted to erosive and/or abrasive challenges., Material and Methods: One hundred and eighty specimens of bovine root dentin were made; half of each was isolated (without treatment - WT) and half was subjected to the following remineralizing techniques: fluoride varnish (FV); Regenerate Boosting Serum® (RBS); Er,Cr:YSGG laser (L); fluoride varnish+laser (FV+L); Regenerate Boosting Serum®+laser (RBS+L). The specimens were submitted to erosive, abrasive and erosive followed by abrasive challenge. Erosion was carried out for 5 minutes, twice a day for 10 days. Abrasion was performed with an electric toothbrush and slurry solution for 60 seconds. The evaluation was performed by confocal laser scanning microscopy. Analysis of variance and Tukey tests were used for surface roughness; volume loss comparison was performed using the Kruskal-Wallis test and Dunn's post-hoc ( p <0.05)., Results: There was no statistically significant difference in the surface roughness of the reference area in relation to the areas submitted to different types of treatment and challenges ( p >0.05). Regarding volume loss, the untreated group submitted to erosive/abrasive challenges showed greater percentage of volume loss compared to the other groups ( p <0.05)., Conclusions: It is concluded that preventive remineralizing techniques are effective in maintaining dentin volume after erosive/abrasive challenges. Key words: YSGG lasers, Dentin, Erosion, Tooth Abrasion., Competing Interests: Conflicts of interest The authors declare no conflict of interest., (Copyright: © 2024 Medicina Oral S.L.)

Background: To evaluate the effectiveness of Er:YAG and Nd:YAG laser on dentin hypersensitivity prevention, associated or not to acidulated phosphate fluoride (APF) after erosive challenge., Material and Methods: 104 specimens were obtained from bovine dentine and divided into groups (n=13): G1: Er:YAG; G2: Er:YAG followed by application of APF; G3: application of APF followed by Er:YAG, simultaneously; G4: Nd:YAG; G5: Nd:YAG followed by application of APF; G6: application of APF followed by Nd:YAG, simultaneously; G7:application of APF; G8: untreated. The parameters for Er:YAG were:10s, distance of 4mm, water cooling flow of 2mL/min, 2Hz, 3.92J/cm2. For the Nd:YAG: 10s, distance of 1mm, without cooling, 10Hz, 70.7J/cm2. The erosive drink was a cola at 4°C, 3×/day for 1 minute, for 5 days. Roughness and wear analysis were done in confocal laser microscope. Data were statistically analyzed (α=0.05)., Results: As regards roughness, there was no statistically difference among the groups. The groups irradiated with Er:YAG had a volume loss lower. G6 showed higher values than the groups irradiated with Er:YAG and lower than the other groups. The other groups irradiated with Nd:YAG showed similar wear results to the control., Conclusions: The Er:YAG laser showed the lowest volume loss from wear analysis, suggesting the increased the acid resistance of dentin. Key words: Dentine sensitivity, Lasers, Sodium fluoride., Competing Interests: Conflicts of interest The authors declare that they have no conflict of interest., (Copyright: © 2024 Medicina Oral S.L.)

Objectives: PITX2 is required for mammalian development and single nucleotide polymorphisms (SNPs) in this gene could be involved in dental agenesis and sella turcica patterns. Thus, the present study evaluated the association between SNPs in PITX2, third molars agenesis and sella turcica phenotypes., Materials and Methods: The sample consisted of healthy orthodontic German patients with lateral cephalometric radiographs with clearly visualization of the sella turcica, and dental orthopantomograms. The morphological variations of the sella turcica were evaluated using the lateral cephalograms, while third molar agenesis was evaluated using orthopantomograms. DNA isolated from buccal cells was used for genotyping three SNPs in PITX2 (rs3796902, rs1947187, and rs2595110). The analyzes were performed using a significance of 5%. There was no association between third molar agenesis and sella turcica phenotypes (p > 0.05). SNPs in PITX2 were also not associated with third molars agenesis (p > 0.05)., Results: SNPs in PITX2 were associated with sella turcica phenotypes. The rs3796902 was associated with hypertrophic posterior clinoid process (p = 0.013). The rs1947187 and rs2595110 were associated with sella turcica bridge type A (p = 0.013 and p = 0.011, respectively for genotype distribution). Patients that carry the genotypes GG-CC-AG (rs3796902- rs1947187- rs2595110) had 7.2 higher chance to present sella turcica bridge type A (p = 0.002; Odds ratio = 7.2, Confidence interval 95% 2.04-27.04)., Conclusions: Third molar agenesis was not associated with SNPs in PITX2 and sella turcica phenotypes. SNPs in PITX2 may have an important role in sella turcica pattern., (© 2024. The Author(s).)

Aim: To evaluate the biological and mechanical properties of an adhesive with nanostructured silver vanadate (AgVO 3 ). Materials & methods: Specimens in poly(methyl methacrylate) (PMMA) were treated with Ultra Corega Cream (UCCA) denture adhesive with or without AgVO 3 . Biofilms of Candida albicans , Candida glabrata and Streptococcus mutans were grown and the viable cells counted. Fluorescence microscopy was used. The viability of the VERO cell and adhesive strength were evaluated. Results: All concentrations of AgVO 3 reduced the biofilm formation and showed no cytotoxic effect. At 5 min and 24 h, UCCA with 5 and 10% AgVO 3 showed better performance, respectively. Conclusion: AgVO 3 promoted the antibiofilm activity of the adhesive, with a positive effect on the adhesive strength, and was biocompatible.

The present cross-over study aimed to evaluate the effect of a visual passive distraction tool, a case for carpule, in the management of fear and anxiety during invasive dental treatment. Children between the ages of 4 and 8 years that need at least two treatments with inferior alveolar nerve block were selected. All the included children received two treatments at different moments: in one treatment, local anesthesia was performed with a visual passive distraction tool, the crocodile case, for carpule (experimental); in the other treatment, local anesthesia was performed without the device (control). An evaluation of the anxiety levels was performed by measuring the heart rate and salivary cortisol levels. Wilcoxon's nonparametric test was used for a data analysis ( p < 0.05). The mean heart rate with the visual passive distraction device fell from 81.8 to 78.1, while the control rose from 91.4 to 100 ( p < 0.05). The mean salivary cortisol levels with the visual passive distraction device fell from 2.0 to 1.6, while in the control, they rose from 2.1 to 2.4 ( p < 0.05). In conclusion, the crocodile case for carpule as a visual passive distraction device contributed positively to the management of fear and anxiety during inferior alveolar nerve block in children.

Purpose: To evaluate the effect of different forms of denture adhesives on the formation of biofilm and on adhesive strength, as well as the effectiveness of hygiene protocols for their removal., Materials and Methods: Samples of the heat-cured polymethyl methacrylate denture base resin were made and divided into four groups: control (no adhesive), ultra Corega cream, Corega strip adhesive, and ultra Corega powder (GlaxoSmithKline). Biofilm formation was evaluated by counting colony-forming units and fluorescence microscopy. To evaluate the effectiveness of the hygiene protocols, the samples were divided into five subgroups: brushing with distilled water; brushing with Protex soap; brushing with Colgate toothpaste; immersion in Corega Tabs; and immersion in Corega Tabs followed by brushing with the solution itself. The remaining adhesive was quantified with ImageJ software. The adhesive strength was tested at different time intervals after application. After verifying the data distribution using Shapiro-Wilk test, parametric or nonparametric analysis was applied (α = .05)., Results: Candida albicans formed more biofilm in strip (P = .007) and powder (P = .001), Pseudomonas aeruginosa in cream (P < .001) and powder (P < .001), and Staphylococcus aureus in strip (P < .001). All forms of the adhesives promoted higher biofilm formation when compared to control (P = .003). Brushing with Colgate and Protex was most effective for removing the adhesives (P < .05). Independently, Powder had the highest adhesive strength (P < .05). Only Strip showed a change in adhesive strength, with higher values after 3 hours of application (P = .004)., Conclusion: Daily treatments with mechanical cleaning of the prosthesis are important for removing the adhesives, since the presence of this material can favor biofilm accumulation. The adhesive strength may vary depending on the commercial type, but all forms can be effective in retaining prostheses for a satisfactory period of time.

Context: Artificial teeth are widely used in oral rehabilitation. Despite the benefits, they are more susceptible to colour changes, causing aesthetic problems., Aims: To evaluate the effect of conventional cigarette and straw smoke on the colour of artificial teeth and the effectiveness of hygiene protocols in removing pigmentation., Material and Methods: Acrylic resin incisors were divided into two groups (n = 50): Exposed to conventional cigarette and straw smoke. Regarding the effectiveness of hygiene protocols, the teeth were divided into ten subgroups with predetermined immersion times. The colour was measured with a colorimeter. The CIE values L* a* b* were recorded before and after exposure to smoke and after hygiene protocols. Statistical analysis used T-test of independent samples and two-way ANOVA with Bonferroni post-test (α = 0.05)., Results: Conventional (16.16 ± 1.65) and straw (16.29 ± 1.95) cigarettes provided clinically unacceptable ΔE values, with no significant difference between them (P = 0.719). Conventional cigarettes promoted less luminosity (ΔL = -12.68 ± 1.28) (P < 0.001) and straw greater tendency to yellow (Δb = 11.00 ± 1.46) (P < 0.001). The hygiene protocols influenced the ΔE, ΔL, and Δb of the samples, depending on the type of smoke (P < 0.05)., Conclusions: The conventional and rolled cigarette smoke promote an unacceptable colour change in artificial teeth. Hygiene protocols with the use of brushing, in isolation or in association with chemical solutions are more effective in removing pigmentation caused by both types of cigarettes compared to only the chemical solution., Competing Interests: None

Persistent primary tooth (PPT) is a prevalent clinical condition that occurs when a primary tooth is over-retained beyond the established period of its normal exfoliation time, remaining in the oral cavity. Many factors could be involved in the risk of PPT; therefore, the aim of this study was to evaluate if single nucleotide polymorphisms (SNPs) in the COX2 gene are associated with PPT. Children undergoing orthodontic treatment were screened. Orthopantomographs were assessed to evaluate PPT according to the Nolla stage of its permanent successor. The primary tooth was considered retained when its successor permanent tooth was in Nolla stage 8 and below the alveolar crypt, Nolla stage 9, or Nolla stage 10. A saliva sample from each child was collected and used for DNA extraction. A real-time PCR of two SNPs, rs689466 (-1195 G/A) and rs5275 (+665 T/C), was performed. A chi-square test was used to compare the allele and genotype distribution. Haplotype analysis was also performed. A total of 100 children were included in the study. Fifty-one had at least one PPT, while 49 children were classified as a control. The number of teeth persistent in the oral cavity ranged from 1 to 8. The genotype distribution was associated with PPT in the co-dominant model ( p = 0.006) for SNP rs5275. The individuals that carry two T alleles (TT) compared with the individuals that carry at least one C allele (C + TC) had an almost three times higher chance of presenting with PPT ( p = 0.012; OR = 2.99, CI95% 1.28 to 6.95-recessive model). The haplotype C-A for the SNPs rs5275 and rs689466, respectively, was significantly associated ( p = 0.042). In conclusion, single nucleotide polymorphisms in the gene encoding for COX2 are associated with persistent primary tooth and may delay permanent tooth eruption.

Background: There is a growing search for innovations in dental materials and instruments and, therefore, an increase need to optimize the instruments used in the absolute isolation. The gold standard procedure contributes significantly to the quality of restorative and endodontic procedures. Thus, the aim of the present study was to evaluate the radiopacity of polyethylene terephthalate polymer clamps and compare them to conventional metal clamps., Material and Methods: The polyethylene terephthalate clamp was developed at the University of Uberaba (Patent application #PI0901719-4, Uberaba, MG, Brazil). Five polyethylene terephthalate clamps and five conventional metal clamps were used. The clamps were positioned, next to an aluminum scale, under the same phosphor plate to perform 3 radiographs. The locator cylinder was set perpendicular to the radiographic films at a focal length of 20 cm and set to 60 kVp and 0.06 seconds. After image processing, optical density values were read using DBWin 5.0.4 software. The mean of the 3 readings taken on each clamp was adopted as the radiodensity of the specimen. The differences between the groups were compared using Student's t-test ( p <0.05)., Results: Polyethylene terephthalate clamps demonstrated significantly lower radiopacity than conventional metal clamps ( p <0.05)., Conclusions: Polyethylene terephthalate clamps have lower radiopacity when compared to conventional metal clamps. Key words: Rubber Dams, Dentistry, Operative, Endodontics., Competing Interests: Conflicts of interest The authors declare that there is no conflict of interest., (Copyright: © 2022 Medicina Oral S.L.)

Skeletal malocclusions are common phenotypes in humans and have a strong influence on genetic factors. Transforming growth factor beta (TGF β ) controls numerous functions of the human body, including cell proliferation, differentiation, and migration. Thus, this study is aimed at evaluating whether genetic polymorphisms in TGFB1 and its receptor TGFBR2 are associated with mandibular retrognathism in German children and adolescents. Children and teenagers older than 8 years in the mixed or permanent dentition were included in this study. Patients with syndromes and facial trauma and patients with congenital alterations were excluded. Digital cephalometric tracings were performed using the anatomical landmarks point A, point B, sella (S), and nasion (N). Patients that have a retrognathic mandible (SNB < 78°) were selected as case group, and the patients with an orthognathic mandible (SNB = 78°- 82°) were selected as the control group. Genomic deoxyribonucleic acid (DNA) from saliva was used to evaluate four genetic polymorphisms in TGFB1 (rs1800469 and rs4803455) and TGBR2 (rs3087465 and rs764522) using real-time PCR. Chi-square or Fisher exact tests were used to compare gender, genotype, and allele distribution among groups. Genotype distribution was calculated in an additive and recessive model. Haplotype analysis was also performed. The established alpha of this study was 5%. A total of 146 patients (age ranging from 8 to 18 years) were included in this epidemiological genetic study. The genetic polymorphism rs3087465 in TGFBR2 was associated with mandibular retrognathism. Carrying the AA genotype in the rs3087465 polymorphism decreased the chance of having mandibular retrognathism (odds ratio = 0.25, confidence interval 95% = 0.06 to 0.94, p = 0.045). None of the haplotypes was associated with mandibular retrognathism ( p > 0.05). In conclusion, we found that the genetic polymorphism rs3087465 in the promoter region of the TGFBR2 was associated with mandibular retrognathism in Germans., Competing Interests: The authors declare no conflict of interest., (Copyright © 2022 Margarita Kirschneck et al.)

Context: A promising option for the prevention of dental caries is the use of laser irradiation., Aims: Evaluate the effects of Er:YAG, Nd:YAG, and CO 2 laser irradiation, associated or not to 2% sodium fluoride (2% NaF), on root caries prevention., Material and Methods: One hundred and four human root dentin samples were divided in eight groups (n = 13). A 9-mm 2 -area on each dentin sample was delimited and treated as follows: G1: no treatment (control); G2: 2% NaF; G3: Er:YAG; G4: 2% NaF + Er:YAG; G5: Nd:YAG; G6: 2% NaF + Nd:YAG; G7: CO 2 ; G8: 2% NaF + CO 2 . When used, the 2% NaF was applied before irradiation for 4 min. The samples were subjected to a 2-week cariogenic challenge, consisted of daily immersion in de-remineralizing solutions for 6 h and 18 h, respectively. Knoop hardness (KHN) were evaluated (10 g and 20 s) at different depths from the dentin surface. The samples (n = 3) were prepared for scanning electron microscopy (SEM). Microhardness data were analysed by one-way analysis of variance (ANOVA) and Fisher's test (α = 5%)., Results: The Er:YAG laser group (KHN = 41.30) promoted an increase in acid resistance of the dentin (P < 0.05) when compared to all groups. There was no synergism between laser irradiation and 2% NaF application. Morphological changes were observed after irradiation with all lasers; carbonization and cracks were also observed, except when Er:YAG were used., Conclusions: Er:YAG laser irradiation can safely increase the acid resistance of the dentin surface of the root, since it promoted a significant increase in surface hardness. The application of 2% NaF did not result in a synergistic effect., Competing Interests: None

This study evaluated how Er,Cr:YSGG laser, associated or not with 5% fluoride varnish, influences the surface roughness and volume loss of bovine root dentin submitted to erosive and/or abrasive wear. One hundred and twenty dentin specimens were divided into the groups: without preventive treatment (WPT), 5% fluoride varnish (FV); Er,Cr:YSGG laser irradiation (L), and varnish combined with laser (FV + L). The specimens (n = 10) were subdivided into: 1 = erosion (E); 2 = abrasion (A); and 3 = erosion followed by abrasion (E + A). The erosive solution used was a soft-drink (pH = 2.42 at 4ºC) applied in 5-min cycles twice a day for 10d. Abrasive wear involved brushing for 60s with an electric brush (1,600-oscillations/s) at a load of 2.0N. Surface roughness and volume loss were evaluated using a laser scanning confocal microscope. Roughness data were submitted to one-way ANOVA and Tukey post-hoc test. For volume loss, the Kruskal-Wallis and Dunn's post-hoc tests were used (α = 5%). The lowest values of roughness were found in the control areas of all subgroups (p > 0.05). In the experimental area, the [(WPT) + (E+A)] subgroup had a significantly higher roughness (5.712 ± 0.163 μm 2 ) than the other subgroups (p < 0.05). The L and (FV + L) groups had statistically similar roughness, regardless of the type of wear. The (FV + L) group had the lowest volume loss, regardless of the type of wear performed: [(FV + L) + (E)] = 7.5%, [(FV + L) + (A) = 7.3%, and [(FV + L) + (E + A)] = 8.1%. The subgroup [(WPT) + (E + A)] had the highest volume loss (52.3%). The proposed treatments were effective in controlling dentin roughness. Laser irradiation can be an effective method to increase root dentin resistance after challenges and limit problems related to non-carious lesions.

The aim of this study was to evaluate, in vivo, the immediate masking effect of white spot lesions (WSLs) treated with an infiltrant resin (IR). The investigation was conducted on 40 young adolescent and adult patients (11 to 23 years old) who presented with at least one permanent maxillary or mandibular anterior tooth with active WSLs on the enamel (ICDAS score 2). Before resin infiltration, the color of both the WSLs and the sound adjacent enamel (SAE) was evaluated by a digital spectrophotometer (CIELab). Subsequently, a resin infiltration technique (Icon) was performed on the WSLs according to the manufacturer's instruction. At the end of the clinical session, the color of the IR was evaluated. The color difference (ΔE) was calculated between WSL × SAE, WSL × IR, and IR × SAE, and then analyzed using one-way analysis of variance (ANOVA), followed by the Tukey's test. The L*, a*, and b* values of WSL, SAE, and IR were compared using the Student's t test for related samples (α = 5%). The ΔE observed was 5.93 ± 0.41 on the WSL × IR comparison, and 5.77 ± 0.41 on the IR × S AE one, indicating that the color of the WSL changed after treatment, but that the infiltration did not fully camouflage the WSLs when compared with the SAE. The lightness was higher for the SAE than for the IR. It was concluded that the IR treatment was not able to camouflage the color of the WSLs when compared with the SAE. However, the treatment was able to attenuate the discoloration of the demineralized dental enamel.

Purpose: To evaluate the influence of the Er,Cr:YSGG laser with or without the 5% fluoride varnish on the acid resistance of dentin after erosive challenge., Methods: 36 incisors were selected and sectioned, obtaining 72 specimens of 4 mm × 4 mm and randomly divided into eight groups (n = 9). In G1: application of Er,Cr:YSGG (0.1W; 5Hz, air 55%); G2: laser (0.25W; 5Hz, air 55%); G3: fluoride varnish + laser (0.1W; 5Hz, air 55%); G4: fluoride varnish + laser (0.25W, 5Hz, air 55%); G5: fluoride varnish + laser (0.1W; 5Hz, without air); G6: fluoride varnish + laser (0.25W, 5Hz, without air); G7: fluoride varnish and G8: no treatment. When used, the laser was irradiated without water cooling, scanning mode during 10 seconds. The surface roughness data were subjected to ANOVA. For wear profile, we used Kruskal-Wallis test and Dunn post-hoc, all with α= 0.05., Results: The results showed no statistically significant difference when comparing the groups as regards to the surface roughness (P> 0.05). Regarding the percentage of lost volume, the G5 and G6 groups presented the best results (G5 = 7.8% and G6 = 8.5%), with the lowest loss of dentin volume compared to other groups (P< 0.05). The G8 group (no treatment) had the highest lost volume (G8 = 39.1% followed by the G7 group (fluoride varnish), which had 25.9%., Clinical Significance: The use of Er,Cr:YSGG laser and fluoride varnish can be an effective method to increase the acid resistance of dentin after erosive challenges, and limit problems related to hypersensitivity., Competing Interests: The authors declared no conflict of interest. The study was supported by FAPEMIG (Fundação de Amparo à Pesquisa do Estado de Minas Gerais) (PEE-01689-16) and CAPES (Coordenação de Aperfeiçoamento de Pessoal de Nível Superior) (Finance Code 001)., (Copyright©American Journal of Dentistry.)

This in vitro study evaluated the influence of the Er,Cr:YSGG laser, associated or not to desensitizing agents, in the prevention of acid erosion in bovine root dentin. Eighty dentin specimens were selected and divided into eight groups (n = 10): G1: negative control; G2: positive control (5% fluoride varnish-FV); G3: Er,Cr:YSGG laser; G4: FV + laser; G5: 3% potassium oxalate; G6: 3% potassium oxalate + laser; G7: biphasic calcium silicate/phosphate gel (gel); G8: gel + laser. Laser parameters: 0.5 W, 6.25 J/cm 2 at 1-mm distance. The erosive drink used was a cola soft-drink (pH = 2.42 at 4 °C), lasting 5 min, twice a day, with 6-h intervals between the challenges, during 14 days. Kolmogorov-Smirnov and Levene's tests were satisfied. The surface roughness data were submitted to ANOVA and Tukey post hoc tests. For the wear profile, Kruskal-Wallis and Dunn post hoc tests were used. Afterwards, the Spearman correlation test was performed. All statistical tests assumed a significance level of 5% (α = 0.05). G1 presented the highest surface roughness value after the erosive challenge (3.586 μm 2  ± 0.205 μm 2 ) and the G7 presented the lowest surface roughness value after the erosive challenge (1.071 μm 2  ± 0.180 μm 2 ). For the lost volume, G4 presented the lowest percentage (9.7% ± 0.9%), while G1 had the highest percentage (41.8% ± 2.5%), both with p < 0.05. There was a weak correlation between the response variables (ρ = 0.33). All groups presented lower values of surface roughness and loss of volume when compared to the negative control group. For the surface roughness, the biphasic calcium silicate/phosphate gel presented the best result. For volume loss, the 5% fluoride varnish + Er,Cr:YSGG laser showed the best results compared to the other groups.

This study analyzed nanostructured silver vanadate (AgVO3) films on certain substrate surfaces found in dental implant devices in order to see if these films promote antimicrobial activity. Enamel and glaze vehicles were used to apply the nanomaterial (0.0% [control], 2.5%, 5.0%, and 10.0% concentrations) on 3 substrates (280 specimens per substrate): polytetrafluoroethylene (PTFE), polyacetal, and acrylic resin. An agar diffusion method was performed in triplicate to determine the antimicrobial activity against 8 microorganisms. Physical behavior and morphologic properties were also analyzed. The growth of Pseudomonas aeruginosa, Escherichia coli, Streptococcus mutans, Enterococcus faecalis, and Staphylococcus aureus was inhibited with the application of AgVO3. For Candida albicans, Porphyromonas gingivalis, and Prevotella intermedia, no antimicrobial activity was observed. Except for S mutans, the type of substrate did not influence the microbiologic results. The glaze showed greater antimicrobial efficacy against S aureus, E faecalis, and S mutans than did the enamel vehicle (P < 0.05). Films with 10% AgVO3 showed greater antimicrobial activity (P < 0.05). The choice of substrate or vehicle did not influence the surface roughness (P > 0.05); however, the application of 10% AgVO3 caused greater surface change (P < 0.05). The application of the nanomaterial did not influence the surface hardness of substrates when compared with the control group (P > 0.05). The use of the glaze as a vehicle provided higher hardness values (P < 0.05).

The aim was to evaluate the surface roughness and bacterial adhesion on enamel irradiated with high intensity lasers, associated or not to a fluoride varnish. Eighty fragments of bovine enamel were equally divided in 8 groups (n=10). Group 1 was not treated and Group 2 received only a 5% fluoride varnish application. The other groups were irradiated with an Er:Cr:YSGG (8.92 J/cm2), an Nd:YAG (84.9 J/cm2) and a diode laser (199.04 J/cm2), associated or not to a 5% fluoride varnish. The surface roughness was measured before and after treatments. Afterward, all samples were incubated in a suspension of S. mutans at 37 °C for 24 h. The colony-forming units (CFU) were counted by a stereoscope and the results were expressed in CFU/mm2. One-way ANOVA and the Tukey´s test compared the roughness data and the Student´s test compared the results obtained in the bacterial adhesion test (a=5%). The results showed that the irradiated samples without varnish presented the same roughness and the same bacterial adhesion that the non-irradiated samples. However, samples irradiated in the presence of fluoride varnish showed higher surface roughness and higher bacterial adhesion than the non-irradiated samples and those irradiated without varnish. Presence of pigments in the varnish increased the lasers' action on the enamel surface, which produced ablation in this hard tissue and significantly increased its surface roughness. For this reason, the enamel's susceptibility to bacterial adhesion was higher when the irradiation of the samples was made in presence of fluoride varnish.

The aim of this study was to compare the compressive strength of a silorane-based composite resin (Filtek P90) to that of conventional composite resins (Charisma, Filtek Z250, Fill Magic, and NT Premium) before and after accelerated artificial aging (AAA). For each composite resin, 16 cylindrical specimens were prepared and divided into 2 groups. One group underwent analysis of compressive strength in a universal testing machine 24 hours after preparation, and the other was subjected first to 192 hours of AAA and then the compressive strength test. Data were analyzed by analysis of variance, followed by the Tukey HSD post hoc test (α = 0.05). Some statistically significant differences in compressive strength were found among the commercial brands (P < 0.001). The conventional composite resin Fill Magic presented the best performance before (P < 0.05) and after AAA (P < 0.05). Values for compressive strength of the silorane-based composite were among the lowest obtained, both before and after aging. Comparison of each material before and after AAA revealed that the aging process did not influence the compressive strength of the tested resins (P = 0.785).

Background: The macrogeometry of dental implants strongly influences the primary stability and hence the osseointegration process., Purpose: Compare the performance of conventional and modified implant models in terms of primary stability., Materials and Methods: A total of 36 implants (Neodent®) with two different formats (n = 18): Alvim CM (Conical CM, Ø 4.3 mm × 10 mm in length) and Titamax Ti (Cylindrical HE, Ø 4.0 mm × 11 mm in length) were inserted into artificial bone blocks. Nine implants from each set were selected to undergo external geometry changes. The primary stability was quantified by insertion torque and resonance frequency using an Osstell device and the pullout test. One-way analysis of variance and Tukey's test were used for statistical evaluation., Results: The comparative analysis of the implants showed a significant increase of the insertion torque for the modified Conical CM implants (p = 0.000) and Cylindrical HE (p = 0.043); for the resonance frequency the modified Cylindrical HE showed a lower statistical mean (p = 0.002) when compared to the conventional model, and in the pullout test both modified implants showed significant reduction (p = 0.000)., Conclusions: Within the limitations of this study, the proposed modification showed good stability levels and advantages when compared to the conventional implants., (© 2015 Wiley Periodicals, Inc.)

Objectives: The purpose of this study was to analyze the influence of the shape of various implants and the density of substrate on primary stability using a combination of methods., Materials and Methods: Fifty-four Neodent® brand cylindrical and conical implants with different prosthetic platforms were used. Implants were inserted into a pork rib bone and polyurethane blocks. Primary stability was assessed by insertion torque (IT), resonance frequency analysis (RFA), and pullout strength. Screws were also analyzed by scanning electron microscopy (SEM) before insertion and after removal to justify their use for inserting in different substrates., Results: The conical cone morse implant had the highest average for all of the assays performed and was significantly different (p < 0.05) from the cylindrical implants for IT in the bone, pullout strength in the 40 per cubic foot (PCF) polyurethane, and the bone. The internal hex cylindrical implant had the lowest averages, which were significantly different (p < 0.05) from the conical implants for IT and RFA in the bone, pullout strength in the 40 PCF polyurethane, and the bone. The IT, RFA, and pullout strength assays were moderately correlated, and the photomicrographs did not reveal changes in the implants., Conclusions: The analysis of different implants showed a better primary stability of tapered implants; the density of the substrate influences the primary stability and the 15 PCF polyurethane was not adequate to evaluate primary stability; correlation was obtained between the different methodologies of analysis of primary stability., Clinical Relevance: The study shows the influence of different implant macro-geometries and densities of substrates on primary stability.

Objective: The aim of this study was to assess any long-term chemical and morphological Nd:YAG laser modifications on irradiated primary enamel., Background Data: Previous studies on irradiated primary human enamel employed methodologies that evaluated the short-term effects only., Methods: One hundred and eighty-six irradiated (with and/or without fluoride) primary enamel teeth from high-caries-risk children, which were exfoliated over a 1-year period, were collected, and the sample surface area was submitted for scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, and X-ray energy-dispersive spectrometry (EDS). The subsurface was analyzed by Knoop microhardness and light microscopy (LM). Data were analyzed by one way ANOVA and Tukey tests (α=0.05) and Kruskall-Wallis and Tukey tests (α=0.05)., Results: FTIR analysis revealed a higher concentration of phosphate and carbonate in the irradiated (0.987±0.064) and lower concentration in the control groups (1.477±0.310). SEM analysis showed that the control samples exhibited a slightly smoother surface than the irradiated groups. The EDS analysis did not show any differences in the amount of calcium, phosphorus, or fluoride among the groups. The microhardness analysis revealed that sealant (249.86±7.15) and laser irradiation (262.44±22.69) led to higher hardness values than the negative control group (128.35±25.19). LM indicated significantly reduced caries formation in the laser (5.35±5.38%) and the laser plus acidulated phosphate fluoride (APF) groups (10.35±0.88%) compared with the negative control group (72.56±12.86%)., Conclusions: Even with the limitations of the present study, these results suggest that Nd:YAG irradiation clinically modified the chemical composition of the enamel surface regardless of fluoride concentration, which successfully inhibited demineralization of primary tooth enamel over a 1-year period without significant morphological changes.

Dental caries is still the most prevalent chronic disease affecting human populations. Among the preventive treatments performed, it has been reported that laser irradiation combined with topical fluoride can induce an even greater increase in enamel caries resistance. The aim of this study was to evaluate the Nd:YAG laser, with or without fluoride, in occlusal caries prevention of the primary dentition. A double-blind split-mouth study design was used. Fifty-two children with high caries risk (7.6 ± 1.4 years) were selected and received the following: G1--the first molar was a negative control, and the second received a resin sealant; G2--the first molar was a negative control, and the second received laser irradiation (50 mJ, 10 Hz, 0.5 W); G3--the first molar received only acidulate phosphate fluoride (APF), and the second received APF + laser; G4--fisrt molar received only fluoride varnish, and the second received fluoride varnish + laser. Patients were followed up to 12 months to evaluate the presence of white-spot lesions and/or caries cavities by three calibrated observers. Thirty-five patients completed the study. Significant differences were found between the treatment and control groups (p < 0.05). The laser-alone and resin sealant resulted in statistically lower caries formation than the negative control group (p < 0.05). Nd:YAG laser irradiation in primary teeth effectively prevented occlusal caries in pits and fissures when used alone with lower energy over a 1-year period.

Purpose: This study's purpose was to evaluate the acid resistance of demineralized enamel irradiated with high-intensity lasers., Methods: Enamel fragments were demineralized and treated as follows (N=10): Group 1-no treatment; Group 2-five percent sodium fluoride (NaF) varnish; Group 3-Er, Cr:YSGG laser (8.92 J/cm2, 0.5 W, 20 Hz, 30 seconds); Group 4-NaF and Er, Cr:YSGG laser; Group 5-Er, Cr:YSGG laser and NaF; Group 6-Nd:YAG laser (84.9 J/cm2, 0.5 W, 10 Hz, 30 seconds); Group 7-NaF and Nd:YAG laser; and Group 8-Nd:YAG laser and NaF. The samples were subjected to pH-cycling and assessed by microhardness (analysis of variance; α equals five percent) at different depths from the outer enamel surface. Samples were observed using polarized light microscopy (PLM) and scanning electron microscopy (SEM)., Results: There were no significant differences among the experimental groups in any of the subsurface layers evaluated. PLM observation revealed that the extent of demineralization of the irradiated samples was similar to the samples for Group 1 (control). SEM observation showed that irradiated surfaces were ablated and presented areas of melting., Conclusions: Laser irradiation, with or without applying five percent sodium fluoride, was not capable of increasing the enamel white spot lesions' acid resistance.

Unlabelled: The use of erbium lasers to prevent caries in enamel has shown positive results. However, it is not known if Er,Cr:YSGG laser can also be used to increase acid resistance of root dentine, which is another dental tissue susceptible to the action of cariogenic bacteria., Objective: To analyze the effects of the Er,Cr:YSGG laser (λ=2.78 μm, 20 Hz) irradiation associated with 2% neutral sodium fluoride (NaF) to prevent root dentin demineralization., Material and Methods: One hundred human root dentin samples were divided into 10 groups (G) and treated as follows: G1: no treatment; G2: NaF; G3: laser (4.64 J/cm2) with water cooling (WC=5.4 mL/min); G4: laser (4.64 J/cm2) without WC; G5: laser (8.92 J/cm2) with WC; G6: laser (8.92 J/cm2) without WC; G7: laser (4.64 J/cm2) with WC and NaF; G8: laser (4.64 J/cm2) without WC and NaF; G9: laser (8.92 J/cm2) with WC and NaF; G10: laser (8.92 J/cm2) without WC and NaF. The NaF gel was applied alone or after 4 min of irradiation. After 14 days of acid challenge, the samples were sectioned and the Knoop microhardness (KHN) test was done at different depths (30, 60, 90 and 120 μm) from the outer dentin surface. Data were analyzed by one-way ANOVA and Fisher's test (α=5%)., Results: The results showed that G8 and G10 presented higher KHN than the G1 for the depths of 30 and 60 μm, indicating an increase of the acid resistance of the dentin in up to 35% (p<0.05)., Conclusions: The use of Er,Cr:YSGG laser irradiation at 4.64 J/ cm2 and 8.92 J/cm2 without water cooling and associated with 2% NaF can increase the acid resistance of human root dentin.

Aim: This study evaluated the influence of surface sealant (Fortify-Bisco) on the color-stability of a composite resin (Charisma-3M) immersed in different beverages., Methods: It was prepared resin specimens with 10 mm-diameter X 2 mm-thickness for each beverage (soft drink, coffee, tea and artificial saliva=control). Specimens were divided in 2 groups (with or without surface sealant) and afterwards divided in 4 subgroups (n=7) according to the immersion solution. After 24 hours, it was started the cycling in the solutions 3 times/day during 5 minutes for 90 days. Opacity (ΔL) and color change (ΔE) of specimens were analyzed with a spectrophotometer (BYK-Gardner) in the different groups in relation to the control group. This handheld portable equipment is unique., Results: Composite resin showed statistically significant difference (p<0.05) in the solutions, and coffee promoted the higher color change, followed by tea and soft drink. There was no difference between specimens sealed or not., Conclusions: Therefore, surface sealant was inefficient on the protection against color change and coffee promoted the higher darkening of the specimens.

Objective: The aim of the present study was to evaluate three mouth rinse solutions' (Plax, Listerine and Periogard) influence on the microhardness and color stability of a composite resin (Esthet.X, Dentsply)., Materials and Methods: For this purpose, forty specimens were prepared, being 10 specimens for each solution and 10 for artificial saliva (control group). Initially, specimens were polished and immersed in artificial saliva and following the initial color, an evaluation was made. For 30 days, specimens were immersed in the solutions three times a day for 1 min. After this cycling period, color change was analyzed and Knoop microhardness measures were carried out. A new color measurement was performed after repolishing the specimens., Results: The microhardness and color stability results showed no statistically significant difference among the studied solutions. However, samples immersed in Periogard showed a significant alteration in the composite resin brightness test., Conclusion: It can be concluded that mouth rinse can influence the luminosity of composite resin.

Objective: The aim of the present study was to evaluate the possible deformations in the surface of dental implants submitted to pullout and insertion test in polyurethane synthetic bone, using scanning electron microscopy., Material and Methods: Four different types of implants were used: Master Screw, Master Porous, Master Conect AR and Master Conect Conical (n = 8). These implants were into the femoral head synthetic bone (Synbone) and removed through the pullout test, performed with a universal testing machine (EMIC MEM 2000). All the screws, before and after the mechanical tests, were micro structurally analyzed in a Scanning Electron Microscope (SEM - Zeiss EVO50), utilizing a magnification of 35 times. The results were subjected to ANOVA and Tukey tests (α =0.05)., Results: Only the Master Conect Conical and Master Porous implants presented statistically significant difference to pullout and maximum deformation (P = 0.014 and P = 0.009, respectively). The SEM images did not show morphological changes of the implants when compared before and after the mechanical tests., Conclusion: We concluded that Master Porous presented higher pullout resistance, suggesting a greater primary stability.

The change in the implant microstructure during handling may reduce the potential of surface treatment on the osteoinduction and, therefore, on the osseointegration. The aim of this study was to evaluate by energy-dispersive X-ray spectroscopy (EDX) the effect of insertion torque and pullout test on the microstructure of dental implants with different shapes. Four shapes of implants (n=8) were selected: conical with surface treatment (COTS), cylindrical with surface treatment (CTS), cylindrical with double surface treatment (CTSD) and cylindrical with machined surface (CSU). Before and after performing the mechanical tests, the screw surfaces were subjected to analysis of chemical composition by EDX. The results obtained by the microstructural analysis showed presence of three main chemical elements: Ti, C and O. There was a significant change in the concentration of Ti and C. The implant with double surface treatment (CTSD) showed the greatest Ti reduction and the greatest C increase. It may be concluded that the mechanical manipulation may alter the implant surfaces as regards their microstructure. Therefore, surgical planning should take into consideration the choice of surface treatment because the characteristics of the implants may be modified as they are inserted and removed from the bone site.

Aim: Researches that assess the behavior of dental materials are important for scientific and industrial development especially when they are tested under conditions that simulate the oral environment, so this work analyzed the compressive strength and microstructure of three composite resins subjected to accelerated artificial aging (AAA)., Methods: Three composites resins of 3M (P90, P60 and Z100) were analyzed and were obtained 16 specimens for each type (N.=48). Half of each type were subjected to UV-C system AAA and then were analyzed the surfaces of three aged specimens and three not aged of each type through the scanning electron microscope (SEM). After, eight specimens of each resin, aged and not aged, were subjected to compression test., Results: After statistical analysis of compressive strength values, it was found that there was difference between groups (α <0.05). The resin specimens aged P60 presented lower values of compressive strength statistically significant when compared to the not subject to the AAA. For the other composite resins, there was no difference, regardless of aging, a fact confirmed by SEM., Conclusion: The results showed that the AAA influenced the compressive strength of the resin aged P60; confirmed by surface analysis by SEM, which showed greater structural disarrangement on surface material.

The objective of this study was to evaluate the effects of chromium:yttrium-scandium-gallium-garnet (Er,Cr:YSGG) laser irradiation on the acid resistance of dental enamel. Forty human enamel samples were divided into four groups. They were manually irradiated with an Er,Cr:YSGG laser device (λ = 2.78 µm, 20 Hz, 20 s), in a scanning mode, with and without water cooling, according to the following parameters: Group 1: 0.25 W, 62.5 J/cm(2), no water cooling; group 2: 0.25 W, 62.5 J/cm(2), 5.0 ml/min; group 3: 0.5 W, 125 J/cm(2), no water cooling; group 4: 0.5 W, 125 J/cm(2), 5.0 ml/min. No airflow was used. Afterwards, the samples were submitted to an acid challenge and assessed by cross-sectional Knoop microhardness at different depths (20, 40, 60, 80, and 100 µm) from the outer enamel surface. Average values were obtained for both irradiated and control areas in each sample and they were compared to obtain a percentage of microhardness increase. Data were analyzed by analysis of variance and Fisher's exact test (α = 5%). The percentage of microhardness increase observed in group 1 (+23.58%) was similar to group 3 (+19.12%), but higher than groups 2 (+3.61%) and 4 (10.9%) (p < 0.05). The comparison of the depths showed that the Er,Cr:YSGG laser acted in the superficial layers of the dental enamel. The findings of the present study suggest that the energy densities of 62.5 and 125 J/cm(2) were capable of increasing the acid resistance of human enamel. The presence of water during irradiation makes it difficult to obtain an enamel surface more resistant to acids.

The aim of the study was to evaluate mechanical behavior of implants inserted in three substrates, by measuring the pullout strength and the relative stiffness. 32 implants (Master Porous-Conexao, cylindrical, external hexagon, and surface treatment) were divided into 4 groups (n = 8): pig rib bone, polyurethane Synbone, polyurethane Nacional 40 PCF, and pinus wood. Implants were installed with the exact distance of 5 mm of another implant. The insertion torque (N·cm) was quantified using the digital Kratos torque meter and the pullout test (N) was performed by an axial traction force toward the long axis of the implant (2 min/mm) through mount implant devices attached to a piece adapted to a load cell of 200 Kg of a universal testing machine (Emic DL10000). Data of insertion torque and maximum pullout force were submitted to one-way ANOVA and Bonferroni tests (α = 0.05). Polyurethane Nacional 40 PCF and pinus wood showed the highest values of insertion torque and pullout force, with significant statistical difference (P < 0.05) with other groups. The analysis showed stiffness materials with the highest values for primary stability.

Aim: The aim of this study was to assess the influence of accelerated artificial aging (AAA) on the surface hardness of acrylic resins., Methods: The following three commercial brands of acrylic resins were tested: Vipi Flash (autopolymerized resin), Vipi Wave (microwave heat-polymerized resin) and Vipi Cril (conventional heat-polymerized resin). To perform the tests, 21 test specimens (65x10x3 mm) were made, 7 for each resin. Three surface hardness readings were performed for each test specimen, before and after AAA, and the means were submitted to the following tests: Kolmogorov-Smirnov (P>0.05), Levene Statistic, Two-way ANOVA, Tukey Post Hoc (P<0.05) with the SPSS Statistical Software 17.0., Results: The analysis of the factors showed significant differences in the hardness values (P<0.05). Before aging, the autopolymerized acrylic resin Vipi Flash showed lower hardness values when compared with the heat-polymerized resin Vipi Cril (P=0.001). After aging, the 3 materials showed similar performance when compared among them. The Vipi Cril was the only one affected by AAA and showed lower hardness values after this procedure (Pp=0.003)., Conclusion: It may be concluded that accelerated artificial aging influenced surface hardness of heat-polymerized acrylic resin Vipi Cril.

This study evaluated the influence of beverages and brushing on the surface roughness(SR) and color change(∆E) of a composite resin.For this, 120-disks(10 mm×2 mm) of composite resin(Filtek-Z250) were prepared and polished. Initials SR(Ra-μm) and color(CIELab-system) were measured with rugosimeter and spectrophotometer; specimens were divided into four groups(red wine, soft drink, sugar cane spirit, or artificial saliva=control) and three subgroups(without brushing; brushed with Colgate or with Close-Up). Specimens were immersed in the beverage 5×/day, for 5', over 30 day, being two subgroups brushed(120 strokes/day). Color was measuredat 15th day, 30th day and after repolishment; SR at 30th day. ∆E-values were statistically different after immersion in the beverages(p<0.05). Red wine promoted the highest alteration, followed by soft drink=sugar cane spirit and finally saliva. At 30th day, specimens exhibited ∆E higher than 15th day; after repolishing, ∆E was similar to 15th day. Beverages and brushing negatively influenced the SR. Therefore, ∆E and SR can be influenced by beverages and brushing.

In this study we compared the microleakage of conventional glass ionomer cement (GIC) restorations following the use of different methods of root caries removal. In vitro root caries were induced in 75 human root dentin samples that were divided in five groups of 15 each according to the method used for caries removal: in group 1 spherical carbide burs at low speed were used, in group 2 a hand-held excavator was used, and in groups 3 to 5 an Er,Cr:YSGG laser was used at 2.25 W, 40.18 J/cm(2) (group 3), 2.50 W, 44.64 J/cm(2) (group 4) and 2.75 W, 49.11 J/cm(2) (group 5). The air/water cooling during irradiation was set to 55%/65% respectively. All cavities were filled with GIC. Five samples from each group were evaluated by scanning electron microscopy (SEM) and the other ten samples were thermocycled and submitted to a microleakage test. The data obtained were compared by ANOVA followed by Fisher's test (p≤0.05). Group 4 showed the lowest microleakage index (56.65 6.30; p<0.05). There were no significant differences among the other groups. On SEM images samples of groups 1 and 2 showed a more regular interface than the irradiated samples. Demineralized dentin below the restoration was observed, that was probably affected dentin. Group 4 showed the lowest microleakage values compared to the other experimental groups, so under the conditions of the present study the method that provided the lowest microleakage was the Er,Cr:YSGG laser with a power output of 2.5 W yielding an energy density of 44.64 J/cm(2).