Esthetic improvements of postorthodontic white-spot lesions treated with resin infiltration and microabrasion: A split-mouth,randomized clinical trial

Objective:To compare the esthetic improvement between postorthodontic white-spot lesions (WSLs) treated by resin infiltration and microabrasion for 12 months.Materials and Methods:A total of 20 patients with 128 teeth with postorthodontic WSLs were recruited. A simple randomized, split-mouth, positive controlled design was used to allocate patients to resin infiltration or microabrasion groups. The lesion area ratio (R value) was calculated between the area of a WSL and the labial surface of the corresponding tooth based on standardized clinical photographs. The color change (ΔE) of each tooth was measured with a Crystaleye spectrophotometer (Olympus, Tokyo, Japan). Every measurement was taken before treatment (T0) and at different time points after treatment: 1 week (T1), 6 months (T6), and 12 months (T12).Results:A total of 16 patients with 108 trial teeth were available at T12. Each group had 54 trial teeth. In both groups, there was a significant decrease in R value and ΔE between T1 and T0 (P < .0001). In the infiltration group, the R value and ΔE had no significant changes over time from T1 to T12. In the microabrasion group, the R value and ΔE decreased significantly from T1 to T6. The R value of resin infiltration was lower when compared with microabrasion at every recall point (P < .001). The ΔE had no significant differences between the two groups at any timepoint.Conclusions:Resin infiltration and microabrasion improved the esthetic appearance of WSLs and showed sufficient durability for 12 months. Resin infiltration showed a better esthetic improvement effect when compared with microabrasion at 12 months.     

Esthetic comparison of white-spot lesion treatment modalities using spectrometry and fluorescence

Objective:To compare the esthetic improvements of white-spot lesions (WSLs) treated by fluoride, casein phosphopeptide amorphous calcium phosphate (CPP-ACP), or resin infiltration.Materials and Methods:WSLs were created on human enamel and randomly assigned to four groups: NaF (500 ppm), CPP-ACP, resin infiltration (Icon), or distilled deionized water (DDW; control group). The color change (ΔE) of each specimen was measured with a Crystaleye spectrophotometer, and fluorescence loss (ΔQ) was measured by quantitative light-induced fluorescence (QLF), at different time points after treatment: baseline (0 weeks), 2 weeks, 4 weeks, and 6 weeks.Results:The ΔE and ΔQ baseline values for the four groups before the treatments did not differ significantly. Icon treatment improved the WSL color significantly and gave the lowest ΔE (2.9 ± 1.2 on average) compared with other treatments (P < .01). The Icon treatment also resulted in a significant change in the ΔQ of WSLs compared with baseline (P < .01). In the NaF and CPP-ACP treatment groups, ΔQ showed significant recovery compared with the baseline values only after 4 weeks after treatment (P < .05).Conclusions:Resin infiltration is more effective than NaF or CPP-ACP in providing esthetic improvement of WSLs.     

Comparison of bleaching effects when applied to white-spot lesions before or after resin infiltration: An in vitro study

BackgroundThe purpose of this study was to compare color alterations (ΔE) of white-spot lesions (WSLs) bleached before versus after resin infiltration (RI).MethodsUsing the facial surfaces of bovine maxillary incisors, WSLs were created and the teeth were allocated into 2 groups (n = 45/group): bleach then RI (B-RI group) and RI then bleach (RI-B group). To determine ΔE, Commission Internationale de l’Eclairage L1 a1 b1 (L1 represents lightness, ranging from black to white [0-100]; a1 represents green to red chromaticity [–150-+100]; and b1 represents blue to yellow chromaticity [–100-+150]) measurements were obtained at baseline, after WSL formation, and after RI and bleaching. Representative specimens were evaluated by means of scanning electron microscopy. Statistical analyses included the Mann-Whitney U and Wilcoxon signed rank tests (P ≤ .0016) and repeated measures analysis of variance (P ≤ .05).ResultsNo differences in ΔE were found comparing B-RI with RI-B groups or when the B-RI group was compared with bleached enamel. A statistically significant difference was found when the RI-B group was compared with bleached enamel (ΔE, 0.81; P < .001), but the difference was deemed not clinically significant. Scanning electron microscopy revealed that bleaching after RI increased surface roughness of the resin.ConclusionsThere were no clinically significant differences in ΔE of WSLs when bleach was applied before or after RI; however, applying bleaching agent after RI roughened the surface of the resin material.Practical ImplicationsResults indicate that ΔE were not clinically significantly different between WSLs bleached before versus after RI, although it is best to sequence bleaching before RI therapy, as bleaching after RI roughened the restoration’s surface.     

Minimally invasive resin infiltration of arrested white-spot lesions: A randomized clinical trial

BackgroundThe authors conducted a randomized, single-masked clinical trial involving patients who had completed orthodontic treatment to assess changes in the appearance of white-spot lesions (WSLs) that were treated with resin infiltration.MethodsThe authors divided affected teeth into control and treatment groups. In the treatment group, they restored teeth with WSLs by using resin infiltration. They evaluated changes in WSLs photographically by using a visual analog scale (VAS) (0 = no change, 100 = complete disappearance) and area measurements (in square millimeters). The authors analyzed the data by using two-way analysis of variance.ResultsThe mean VAS ratings for treated teeth demonstrated marked improvement relative to that for control teeth immediately after treatment (67.7 versus 5.2, P < .001) and eight weeks later (65.9 versus 9.2, P < .001). The results for treated teeth showed a mean reduction in WSL area of 61.8 percent immediately after treatment and 60.9 percent eight weeks later, compared with a ?3.3 percent change for control teeth immediately after treatment and a 1.0 percent reduction eight weeks later.ConclusionsResin infiltration significantly improved the clinical appearance of WSLs, with stable results seen eight weeks after treatment.Practical ImplicationsResin infiltration, a minimally invasive restorative treatment, was shown to be effective for WSLs that formed during orthodontic treatment.     

Camouflage effects following resin infiltration of postorthodontic white-spot lesions in vivo: One-year follow-up

Objective:To assess camouflage effects by concealment of postorthodontic white-spot lesions (WSLs) to sound adjacent enamel (SAE) achieved over 12 months with resin infiltration (Icon, DMG, Hamburg, Germany).Methods: Twenty subjects (trial teeth n_teeth = 111) who had received resin infiltration treatment of noncavitated postorthodontic WSLs were contacted for a 1-year follow-up assessment of CIE-L*a*b* colors (T12). Color and lightness (CIE-L*a*b*) data for WSLs and SAE were compared to baseline data assessed before infiltration (T0) and those assessed after 6 months (T6), using a spectrophotometer. The target parameter was the difference between the summarized color and lightness values (ΔE_WSL/SAE). Intergroup (WSL, SAE) and intertime comparisons (T0 vs T6, T12) were performed using paired t-tests at a significance level of α = 5%.Results:Nine subjects (trial teeth n_teeth = 49; male/female ratio 5/4; age range 13–19 years) were available at T12. After the highly significant reduction of ΔE_WSL/SAE discrepancies between T0 and T6, analysis of 12-month records revealed color and lightness discrepancy of WSL vs SAE that was significantly decreased compared with baseline, indicating an assimilation of WSL color to SAE appearance after infiltration, while an additional reduction of discrepancies between T6 and T12 was not significant.Conclusion:As color and lightness characteristics of the Icon infiltrant as well as the esthetic camouflage effects achieved by WSL infiltration were not altered significantly or clinically relevant after 12 months, the method of resin infiltration can be recommended for an enduring esthetic improvement of postorthodontic WSL. (Angle Orthod. 2015;85:374–380.)     

Incidence of white spot lesions among patients treated with clear aligners and traditional braces

Objectives:To compare the incidence of white spot lesions (WSLs) among patients treated with aligners and those treated with traditional braces.Materials and Methods:A group of 244 aligner patients (30.4 ± 14 years) was compared to a group of 206 patients (29.2 ± 11.5 years) treated with traditional fixed braces. Consecutive cases in the late mixed or permanent dentitions who had high-quality pre- and posttreatment digital photographs available were included in the study. Each set of photographs was independently evaluated by two investigators to determine pretreatment oral hygiene (OH), fluorosis, and WSLs, as well as changes in OH and WSLs during treatment.Results:Approximately 1.2% of the aligner patients developed WSLs, compared to 26% of the traditionally treated patients. The numbers of WSLs that developed were also significantly (P < .001) less among the aligner patients. The aligner patients developed three new WSLs, while the traditionally treated patients developed 174 WSLs. The incidence of WSLs was greater for the maxillary than for the mandibular teeth, and it was greater for the canines than for the incisors. For the patients treated with traditional braces, fair or poor pretreatment OH, worsening of OH during treatment, preexisting WSLs, and longer treatment duration significantly (P < .05) increased the risk of developing WSLs during treatment.Conclusions:Patients treated with aligners have less risk of developing WSLs than do patients treated with traditional braces, which could be partially due to shorter treatment duration, or better pretreatment OH.     

Do total or partial etching procedures effect the rate of white spot lesion formation? A single-center,randomized, controlled clinical trial

Objective:To determine whether total or partial etching procedures influence the appearance of white spot lesions (WSLs).Materials and Methods:This split-mouth, double-blind, controlled, randomized study included 20 patients (mean age 16.75 years), who had class I malocclusion, mild crowding, and satisfactory oral hygiene. A total of 40 maxillary quadrants were randomly allocated to be treated using a total etching (TE) or partial etching (PE) protocol. Quantitative light fluorescence images were captured at the beginning and at 3 (T1) and 6 (T2) months after beginning orthodontic treatmen, as well as when the debonding phase of orthodontic treatment was complete (T3). The presence of pre- and posttreatment WSLs was assessed with quantitative light fluorescence software and analyzed with Student''s t-test.Results:The analyses showed that, at T2, the total etching group had significantly higher ΔQ and A scores than the partial etching group (P < .05). The ΔF scores increased significantly at all timepoints in the TE group, but only at T1 and T3 in the PE group. However, no differences were noted at T3 between the TE and PE groups (P > .05). The inclusion of only right-handed people may have limited the generalizability of the findings. The absence of analyses of the plaque and gingivitis scores of patients was another limitation of this study.Conclusions:WSL formation was observed mostly in maxillary lateral incisor teeth irrespective of the etching technique. Although PE seems to be more successful in the first 6 months, no difference was observed between PE and TE in the long term for WSL formation.     

Prevalence of white spot lesion formation during orthodontic treatment

Purpose:To quantify the prevalence of white spot lesions (WSLs) on the anterior teeth and, secondarily, to evaluate risk factors and predictors.Materials and Methods:Digital photographs and records of 885 randomly chosen patients were evaluated before and after treatment. Chart information included gender, age, as well as banding and debanding dates. Fluorosis and oral hygiene before and after treatment were also evaluated. Preexisting and posttreatment WSLs were recorded and compared for all 12 anterior teeth. Risk ratios (RR) and absolute risk (AR) were calculated to determine the likelihood and risk of WSL formation.Results:Overall, 23.4% of the patients developed at least one WSL during their course of treatment. Maxillary anterior teeth were affected more than mandibular teeth. The maxillary laterals and canines and the mandibular canines were the most susceptible. There was no significant difference in WSLs between genders. Fluorosis, treatment time in excess of 36 months, poor pretreatment hygiene, hygiene changes during treatment, and preexisting WSLs were all significantly (P < .05) related to the development of WSLs. The highest risk of developing WSLs was associated with preexisting WSLs (RR = 3.40), followed by declines in oral hygiene during treatment (RR = 3.12) and poor pretreatment oral hygiene (RR = 2.83).Conclusions:Nearly 25% of the patients developed WSLs while in treatment, depending on fluorosis, treatment time, preexisting WSLs, and oral hygiene. Orthodontists need to be mindful of these risk factors when making treatment decisions.     

Pulp blood flow and sensibility in patients with a history of dental trauma undergoing maxillary expansion:: A prospective study

ObjectivesTo assess changes in pulp blood flow (PBF) and pulp sensibility (PS) in teeth of patients with a history of dental trauma undergoing maxillary expansion.Materials and MethodsTwenty-five patients requiring rapid maxillary expansion (RME) had the pulp status of their maxillary anterior teeth assessed using laser Doppler flowmetry, electric pulp testing, and thermal testing (CO2 snow). Each patient was tested at T1 (prior to expansion), T2 (2 weeks after rapid expansion), and T3 (3 months after expansion). Relationships between PBF, time interval, and history of trauma were evaluated using linear mixed modelling.ResultsWithin the Trauma group, PBF was significantly lower (P ≤ .05) at T2 and T3 in comparison to T1 and significantly lower (P ≤ .05) at T2 in comparison to T3. In the Non-trauma group, PBF at T2 was significantly lower (P ≤ .05) than PBF at T1 and T3; however, no significant difference (P > .05) in PBF was observed when comparing PBF at T1 and T3. In both groups, PS was maintained in almost all teeth (>90%).ConclusionsRME in healthy teeth causes reduction of PBF before reestablishment of pretreatment values. RME in traumatized teeth causes reduction of PBF without PBF being reestablished to pretreatment levels. Teeth with a history of compromise may have reduced adaptive capacity under insults such as RME, which should be appreciated during the informed consent process.     

Effects of severity and location of nonsyndromic hypodontia on craniofacial morphology

Objective:To evaluate the effects of severity and location of nonsyndromic hypodontia on craniofacial morphology.Materials and Methods:A total of 154 patients with at least two or more congenitally missing teeth were selected and divided into two groups (group I [mild]: patients with two to five missing teeth; group II [severe]: patients with six or more missing teeth). The patients with hypodontia were divided into three groups according to the location of missing teeth in the dental arches (anterior, posterior, and both anterior and posterior) and location of missing teeth between the jaws (maxilla, mandible, and both maxilla and mandible). Fifty Class I patients without any missing teeth served as the control group. Twenty-one measurements were performed on lateral cephalograms. Intergroup differences for the severity and location of hypodontia were analyzed using analysis of variance (ANOVA) and post-hoc Tukey tests.Results:Significant decreases were found in mandibular plane angles (P < .05), upper and lower incisor measurements (P < .05), anterior (P < .001) and posterior (P < .05) face heights, and ramus height (P < .01), as well as a significant increase in the soft tissue convexity angle (P < .05) among the hypodontia groups and control group. These differences were more excessive in the severe hypodontia group. Upper lip-E plane measurements were significantly longer in the mandible group than in the maxilla group (P < .01).Conclusions:Patients with congenitally missing teeth have different craniofacial morphologies. The severity and location of missing teeth have a significant effect.     

Microhardness of resin cements after light activation through various translucencies of monolithic zirconia

PURPOSEThis study aimed to investigate the Vickers Hardness Number (VHN) of light- and dual cured resin cements cured through monolithic zirconia specimens (VITA YZ) of various translucencies: translucent (T); high translucent (HT); super translucent (ST); and extra translucent (XT) at 0, 24, and 48 h after curing.MATERIALS AND METHODSFour zirconia specimens from each translucency were prepared. Two light-cured resin cements (Variolink N LC; VL and RelyX Veneer; RL) and two dual-cured resin cements (Variolink N DC; VD and RelyX U200; RD) were used. The cement was mixed and loaded in a mold and cured for 20 s through the zirconia specimen. The upper surface of cements was tested for VHN using a microhardness tester at 0, 24, and 48 h after curing. The VHN were analyzed using two-way repeated, Brown-Forsythe ANOVA with Games Howell post-hoc analysis and independent t-tests (P < .05).RESULTSAll cements showed significantly higher VHN from 0 h to 24 h (P < .001). At 48 h, the VHN of light-cured cements were significantly lower when cured under the T groups than under XT groups (P = .001 in VL, P = .014 in RL). At each post curing time of each translucency, VD showed higher VHN than VL (P < .05), and RD also showed higher VHN than RL (P < .05).CONCLUSIONThe translucency of zirconia has an effect on the VHN for light-cured resin cements, but has no effect on dual-cured resin cements. Dual-cured resin cement exhibited higher VHN than the light-cured resin cement from the same manufacturer. All resin cements showed significantly higher VHN from 0 h to 24 h.     

Diagnosing the severity of buccal caries lesions in governmental and private orthodontic patients at debonding,using the ICDAS-II and the DIAGNOdent Pen

Objectives: To clinically evaluate the prevalence of buccal caries and white spot lesions (WSLs) at debonding in governmental and private orthodontic patients, using the International Caries Detection and Assessment System (ICDAS-II) and the DIAGNOdent Pen, and to study the correlation between the two methods.Materials and Methods:A cross-sectional study was carried out on the nonextracted premolars and anterior teeth of 89 orthodontic patients. They were recruited into two groups based on the treatment center they attended: governmental group (G; n  =  45) and private group (P; n  =  44). Immediately after debonding, the examination of buccal caries and WSLs on premolars and anterior teeth was carried out using the ICDAS-II and the DIAGNOdent Pen. Cross-tabulation was applied to study the correlation between the ICDAS-II index and the DIAGNOdent Pen by calculating the Spearman correlation coefficient.Results:The G group showed a significantly higher (P < .0001) prevalence of WSLs and/or buccal caries compared to that of the P group based on evaluation by the two methods. Based on ICDAS-II, 43% of the patients in the P group and 9% in the G group were free from any WSLs. In the G group, 22% of the patients had ≥16 lesions, whereas there were none for the P group. The Spearman correlation coefficient between the two methods was .71.Conclusions:The prevalence of caries and/or WSLs at debonding was significantly higher in the G group compared to the P group. The clinical index (ICDAS-II) showed a good correlation with the DIAGNOdent Pen.     

Effect of bracket type on halitosis,periodontal status,and microbial colonization

Objective: To determine the effect of bracket type on halitosis, periodontal status, and microbial colonization.Materials and Methods:Forty-six patients scheduled for fixed orthodontic treatment (age 11–16 years) were selected from the orthodontic department of Suleyman Demirel University. Patients were divided into two groups with random distribution of brackets; 23 patients were treated with self-ligating brackets (group SLBs), the others with conventional brackets (group CBs). Halitosis measurements and periodontal and microbial records were obtained before the placement of brackets (T0), 1 week later (T1), and 5 weeks after bonding (T2). Periodontal parameters, including plaque index (PI), gingival index (GI), and bleeding on probing index (BOP), were obtained from all the bonded teeth. Halitosis measurements were performed at the same time. Microbial samples were obtained from the buccal surfaces of all the bonded teeth. Data were analyzed by using a repeated-measurement analysis of variance test for the comparison of parameters between groups and times.Results:Periodontal parameters and halitosis results were higher in the CBs group than in the SLBs group (P < .05). In the SLBs group, halitosis and BOP values revealed no pronounced changes between T1 and T2 (P > .05). Intra- and intergroup comparisons showed that there were no statistically significant differences for microbial colonization between all the time intervals (P > .05).Conclusion:Bracket type has an effect on halitosis and periodontal status. Therefore, self-ligating brackets may be advised in order to prevent patients from developing halitosis and to increase the likelihood of good oral hygiene during orthodontic treatment.     

The efficacy of fluoride varnish vs a filled resin sealant for preventing white spot lesions during orthodontic treatment:: A randomized clinical trial

ObjectivesTo compare the efficacy of casein phosphopeptide (CPP)-amorphous calcium phosphate (ACP) MI Varnish (GC America, Inc, Alsip, IL) and ProSeal (Reliance Orthodontic Products, Itasca, IL) sealant in preventing the development of white spot lesions (WSLs) in orthodontic patients.Materials and MethodsThis prospective randomized clinical trial included 40 orthodontic patients 12–17 years of age. One group had sealants placed on their anterior maxillary teeth, with reapplications every 3 months. The other group had MI Varnish applied every 4–6 weeks. WSL formation and oral hygiene were evaluated at the initial appointment before bonding (T1) and 12 months later (T2). Standardized digital photographs were analyzed using the enamel decalcification index (EDI). Statistical comparisons were made using independent and paired-sample t-tests as well as chi-square tests.ResultsIn this trial, 43% of patients and 15% of teeth developed new WSLs. Lateral incisors showed the highest incidence of decalcification and WSL formation. WSL formation and EDI score increases during treatment were significantly greater in the gingival region than in the mesial, distal, or incisal regions. Of the EDI scores at T2, 93.8% were 0 and 5.5% were 1. Poor oral hygiene at T2 showed a high positive predictive value (76%) for the development of WSLs. There were no statistically significant between-group differences for the development of WSLs.ConclusionsMI Varnish and ProSeal sealant provided similar levels of protection during the first 12 months of fixed orthodontic treatment. The severity of the WSLs that developed was minimal. WSLs were most likely to develop on lateral incisors and in the gingival regions of teeth, especially among patients with poorer oral hygiene.     

Three-dimensional soft tissue evaluation after rapid maxillary expansion and mandibular midline distraction osteogenesis

ObjectivesTo evaluate the effects of rapid maxillary expansion (RME) and mandibular midline distraction osteogenesis (MMDO) on facial soft tissues using three-dimensional (3D) images.Materials and MethodsA total of 20 patients (average age 15.86 ± 2.17 years) were treated with RME and MMDO using tooth-borne distractors. Three-dimensional photographs of each patient were taken with a stereophotogrammetry system at baseline (T0), at the end of the distraction period (T1), and at the end of the consolidation period (T2). All data were analyzed using a dependent-samples t-test at a significance level of 5%.ResultsTotal and lower face height increased after MMDO (P < .05). Nasal and mouth width increased after RME as compared with baseline (P < .05). The labiomental angle increased at T1 and decreased at T2 (P < .05). After MMDO, the convexity angle increased while the mandibular angle decreased (P < .05). Upper and lower lip angles increased after RME (P < .05). The distance from the lower lip to the E plane increased after MMDO and decreased after RME (P < .05).ConclusionsThe MMDO and RME procedures provide an efficient nonextraction treatment alternative for transverse maxillomandibular deficiency. MMDO may improve the facial soft tissue profile in the transverse and vertical axis of the mandibular region.     

Assessment of changes in the nasal airway after nonsurgical miniscrew-assisted rapid maxillary expansion in young adults

Objectives:To evaluate changes in the volume and cross-sectional area of the nasal airway before and 1 year after nonsurgical miniscrew-assisted rapid maxillary expansion (MARME) in young adults.Materials and Methods:Fourteen patients (mean age, 22.7 years; 10 women, four men) with a transverse discrepancy who underwent cone beam computed tomography before (T0), immediately after (T1), and 1 year after (T2) expansion were retrospectively included in this study. The volume of the nasal cavity and nasopharynx and the cross-sectional area of the anterior, middle, and posterior segments of the nasal airway were measured and compared among the three timepoints using paired t-tests.Results:The volume of the nasal cavity showed a significant increase at T1 and T2 (P < .05), while that of the nasopharynx increased only at T2 (P < .05). The anterior and middle cross-sectional areas significantly increased at T1 and T2 (P < .05), while the posterior cross-sectional area showed no significant change throughout the observation period (P > .05).Conclusions:The results demonstrate that the volume and cross-sectional area of the nasal cavity increased after MARME and were maintained at 1 year after expansion. Therefore, MARME may be helpful in expanding the nasal airway.     

Modification of surface pre-treatment for resin infiltration to mask natural white spot lesions

Objectives

The aims of this study were to investigate an alternative pre-treatment method for resin infiltration using 37% H₃PO₄ with a brush applicator and to evaluate the penetration effect of the infiltrant for masking the natural white spot lesions (WSLs) in human teeth.

Methods

Seventy extracted human molars and pre-molars with non-cavitated WSLs were collected. Thirty teeth met criteria of ICDAS code 2, and were sectioned, providing a total of sixty paired halves. For the control group, 15% HCl gel was applied for 120 s, and 37% H₃PO₄, gel was gently rubbed with a brush applicator for 30 s to the experimental group. Also, to evaluate the penetration effect of the infiltrant by pre-treatment, the specimens were treated with the infiltrant (Icon^®). Thicknesses of the removed surfaces and percentages of the infiltrated areas (IA%) were evaluated by CLSM, and micro-morphological changes were observed by SEM.

Results

The mean thicknesses of removed surface layers were significantly different between the control group (36 ± 7.62 μm) and the experimental group (13 ± 2.76 μm) (p < 0.001). But, the means of IA% were similar in both groups (p > 0.05). In the SEM images, the prism cores were preferentially dissolved in the control group, while the prism peripheries were preferentially dissolved in the experimental group.

Conclusions

Applying 37% H₃PO₄ gel with an applicator brush for 30 s could increase the permeability and minimize removal of the surface layer of natural WSLs. Moreover, the effect of resin infiltration was similar to the control group which was pretreated 15% HCl gel for 120 s in vitro study.

Clinical significance

For resin infiltration, applying 37% H₃PO₄ gel with a brush applicator can preserve the protective surface layers of the WSLs with reduced application time.     

In vivo effect of antibacterial and fluoride-releasing adhesives on enamel demineralization around brackets: A micro-CT study

Objectives:The aim of this in vivo study was to investigate the preventive effect of two different adhesives on enamel demineralization and compare these adhesives with a conventional one.Materials and Methods:Fifteen patients requiring the extraction of their first four premolars for orthodontic treatment were included in the study. One premolar was randomly selected, and an antibacterial monomer-containing and fluoride-releasing adhesive (Clearfil Protect Bond, Kuraray Medical, Okayama, Japan) was used for orthodontic bracket bonding. Another premolar was randomly selected, and a fluoride-releasing and recharging orthodontic adhesive (Opal Seal, Ultradent Products, South Jordan, Utah) was used. One premolar was assigned as a control, and a conventional adhesive (Transbond XT, 3M Unitek, Monrovia, Calif) was used. The teeth were extracted after 8 weeks, and the demineralization areas of the 45 extracted teeth were analyzed using microcomputed tomography with software.Results:There was no significant difference between the white spot lesion (WSL) rates of the adhesives (P > .05). The volumes of the WSLs varied from 0 to 0.019349 mm³. Although Opal Seal showed the smallest lesion volumes, there was no significant difference in volumetric measurements of the lesions among the groups (P > .05).Conclusions:The findings indicated no significant differences between the preventive effects of the adhesives used in this in vivo study over 8 weeks.     

Pharyngeal airway space,hyoid bone position,and head posture after bimaxillary orthognathic surgery in Class III patients: Long-term evaluation

Objective:(1) To determine the effect of bimaxillary orthognathic surgery on pharyngeal airway, hyoid bone, and craniocervical posture in Class III bimaxillary surgery patients. (2) To evaluate short-term and long-term results. (3) To compare short- and long-term values.Materials and Methods:Twenty-six Class III adult patients treated with bimaxillary surgery were included in the study. Cephalometric records were taken before treatment (T1), before surgery (T2), and 5 months (T3), 1.4 years (T4), 3 years (T5), and 5 years (T6) postsurgery.Results:No significant differences were identified in craniocervical angulation between time intervals. There was a significant superior movement of hyoid bone at postsurgery (T3; P < .05); however, adaptation occurred to the normal position in the long term. A nonsignificant decrease occurred at the oropharyngeal middle pharyngeal distance parameter; however, this was compensated with a significant increase between T5 and T6 (P < .001). A significant decrease was observed in the hypopharyngeal Go-P parameter between T3 and T1 (P < .01), but it recovered with a nonsignificant increase in the long term. A significant increase in nasopharyngeal area was observed between T3 and T1 (P < .05). The hypopharyngeal area significantly increased between T5 and T6, and PNS-R significantly increased between T3 and T1 (P < .05).Conclusion:The pharyngeal areas adversely affected after surgery recover at long-term follow-up; thus, adaptation occurs after bimaxillary surgery.     

Effect of repair methods and materials on the flexural strength of 3D-printed denture base resin

PURPOSEThe aim of this study was to evaluate the flexural strength of a 3D-printed denture base resin (Cosmos Denture), after different immediate repair techniques with surface treatments and thermocycling.MATERIALS AND METHODSRectangular 3D-printed denture base resin (Cosmos Denture) specimens (N = 130) were thermocycled (5,000 cycles, 5℃ and 55℃) before and after the different repair techniques (n = 10 per group) using an autopolymerized acrylic resin (Jet, J) or a hard relining resin (Soft Confort, SC), and different surface treatments: Jet resin monomer for 180 s (MMA), blasting with aluminum oxide (JAT) or erbium: yttrium-aluminum-garnet laser (L). The control group were intact specimens. A three-point flexural strength test was performed, and data (MPa) were analyzed by ANOVA and Games-Howell post hoc test (α = 0.05). Each failure was observed and classified through stereomicroscope images and the surface treatments were viewed by scanning electron microscope (SEM).RESULTSControl group showed the highest mean of flexural strength, statistically different from the other groups (P < .001), followed by MMA+J group. The groups with L treatment were statistically similar to the MMA groups (P > .05). The JAT+J group was better than the SC and JAT+SC groups (P < .05), but similar to the other groups (P > .05). Adhesive failures were most observed in JAT groups, especially when repaired with SC. The SEM images showed surface changes for all treatments, except JAT alone.CONCLUSIONDenture bases fabricated with 3D-printed resin should be preferably repaired with MMA+J. SC and JAT+SC showed the worst results. Blasting impaired the adhesion of the SC resin.