Diagnostic Methods for the Prenatal Detection of Cleft Lip and Palate: A Systematic Review.

Background: Accurate prenatal diagnosis of cleft lip and palate is essential to discuss severity prediction, perform appropriate parental counseling, and, at last, establish long-term treatment planning. The aim of this systematic review was to analyze the accuracy of various imaging techniques for the prenatal diagnosis of cleft lip and palate, assess the pregnancy phase for orofacial clefts diagnosis, and study the different cleft types in terms of diagnostic methods, timing, and predictability. Methods: A search of the PubMed, EMBASE, Scopus, and Web of Science databases was conducted to identify potentially relevant studies published until January 2024. The quality of the selected articles was assessed using the Newcastle-Ottawa scale for methodological quality assessment of cohort studies and the QUADAS-2 scale for diagnostic test studies. Results: A total of 18 studies met the eligibility criteria and were included in the review. The findings of this review indicate that the majority of studies showed improved diagnostic accuracy when supplementary techniques, such as 3D ultrasound or magnetic resonance imaging, were added to 2D ultrasound. Conclusions: The implementation of magnetic resonance imaging as a standard procedure could significantly improve the precision of diagnosing cleft lip and palate. Therefore, the diagnostic technique used will play a crucial role in the accuracy of the diagnosis.

Volatile sulfur compounds in asthmatic children and adolescents: A cross-sectional study in breath and saliva.

BACKGROUND: Halitosis in children implies psychosocial repercussions. Risk factors associated with this condition are unclear, and detection methods are inaccurate. AIM: To quantify the levels of sulfur-like compounds in children with asthma and healthy children from a novel validated assay, and to establish the risk factors related to halitosis. DESIGN: One hundred and twenty-eight individuals (63 healthy and 65 asthmatic) from 3 to 17 years of age were tested using a passive colorimetric sensor to measure the levels of sulfur-like compounds in breath and saliva. Information was collected on oral hygiene habits, gingival and dental health, breathing type, and dental malocclusion. RESULTS: The mean values of hydrogen sulfide were 4.0 ± 6.8 and 19.7 ± 12.2 ppbv (parts per billion in volume) in the control and asthmatic groups, respectively (p < .001). The presence of higher concentrations of sulfur compounds was significantly associated (p < .05) with the presence of gingival inflammation, tongue coating, dental plaque, mouth breathing, hypomineralization, age, tongue brushing, and the use of dental floss. CONCLUSION: The level of sulfur in breath and saliva was significantly higher in patients with asthma. These results can serve as a precedent to raise awareness among paediatricians and parents about oral hygiene care in children and adolescents.

Nonsurgical treatment of an adult with skeletal Class III malocclusion, posterior crossbite and mandibular asymmetry.

Class III malocclusion represents a very heterogeneous clinical condition that is characterized by the combination of a wide variety of skeletal and/or dental components. Given the wide diversity, diagnosis and treatment of such malocclusion has always been a challenge for clinicians. Despite the different treatment options available, the treatment approach in the adult patient must depend fundamentally on the patient's decision, guided by the orthodontist and the maxillofacial surgeon. This case report presents the treatment of a patient with Class III malocclusion, with posterior crossbite and anterior edge-to-edge bite with fixed appliances and skeletal anchorage, an interdisciplinary, nonsurgical approach for a skeletal malocclusion. Firstly, to improve the posterior transverse relationship a band-soldered compressed lingual arch was cemented to the mandibular first molars. Then, once a correct transverse relationship was achieved, two miniscrews were placed distal to the mandibular second molars to distalize the whole mandibular arch, and avoid excessive inclination of maxillary incisors to improve dentofacial esthetics. At the end of the treatment, all the objectives planned at the beginning had been achieved and remained stable after the retention period. Key words:Clase III, orthodontic treatment, distalizing, appliances, posterior crossbite.

Improving the Antibacterial Properties of Dental Bonding Materials Loaded with Silver Compounds.

Biofilm accumulation, the appearance of white spot lesions and the development of secondary caries are the main complications in orthodontic patients. A promising approach to fight this situation is the development of adhesive cements with improved antibacterial properties. The aim of the present study was to evaluate the possibility of improving the antibacterial properties of glass ionomer cements by incorporating different types of antimicrobial compounds without altering their physical and mechanical properties. Different concentrations of silver carbonate (SC) and an inorganic glass with encapsulated silver were added to the glass ionomer cement, as well as chitosan, to achieve synergistic antibacterial activity. Variations in the antibacterial capacity were evaluated using the agar diffusion test; the potential alteration of the physical and mechanical properties of the material was analyzed by the shear bond strength test. SEM characterization and colorimetric evaluation were also conducted. Samples of SC up to 1% and inorganic glass with encapsulated silver up to 5% showed significant improvement in their antibacterial ability without compromising shear strength. The highest antimicrobial activity was observed for Lactobacillus acidophilus, with inhibition zones of 3.8 and 3.1 mm for SC and inorganic glass, respectively. The characterization of the samples did not detect any major structural changes between the different samples. The only group that underwent a noticeable color change was the group with SC. The results show that the incorporation of silver carbonate and inorganic glass with encapsulated silver provided the glass ionomer cement with an antibacterial capacity without compromising the bond strength and without modifying the structure of the material.

Label-free SERS for rapid identification of interleukin 6 based on intrinsic SERS fingerprint of antibody­gold nanoparticles conjugate.

A label-free surface-enhanced Raman scattering (SERS) was designed for sensitive detection of interleukin-6 (IL-6). The sensing element composed of anti-IL-6 antibodies adsorbed on the surface of spherical gold nanoparticles (AuNPs) as SERS-active surface. The principle of detection was probing antibody conformational changes using its intrinsic SERS fingerprint after binding to IL-6. Comparison of SERS spectra of antibody before and after binding to IL-6 showed that secondary structure of antibody does not change upon binding to IL-6. Vibrational information from disulfide bonds ν(SS) in antibody structure indicated some changes of geometry around SS bridges as a consequence of the immunocomplex formation. Transmission electron microscopy (TEM) and UV-Vis spectroscopy were used to confirm AuNPs conjugation with antibody as well as IL-6 binding to antibody on the surface of AuNPs. The SERS-based immunoassay showed a wide linear range (2.0-1000 pg mL-1) and a high sensitivity with a limit of detection (LOD) as low as 0.91 pg mL-1 (0.04 pM) without using any extrinsic Raman label. UV-Vis spectroscopy was employed as a conventional method for IL-6 detection based on observation of any change in the position of localized surface plasmon resonance (LSPR) band of AuNPs-antibody conjugates with LOD of 10 ng mL-1.

Scientific production of an oral implantology journal: a 5-year bibliometric study.

Oral implantology is a science in constant evolution, with a considerable number of articles being published every year in scientific journals. Publications can be analyzed through bibliometric analysis, thus observing the evolution and trends of the articles published in the journal. To evaluate, through bibliometric analysis, the scientific production of Clinical Implant Dentistry and Related Research (CIDRR) and its evolution and trends in the last 5 years (2016-2020).All articles published in CIDRR in the last 5 years were reviewed and classified according to the year of publication, volume, number, the number of authors, demographic data of the first and last author, the geographical scope of the article, the number of affiliations of the authors, research topic, type of study, and study design. The association between these variables and citation counts was also analyzed. 599 articles were analyzed. 77.4% were authored by 4-6 authors, obtaining 78.4% from 1 to 3 different affiliations. Male researchers predominated in both the first and last authorship. China showed the highest number of publications when comparing the origin of the authors' affiliations individually; however, most researchers (40.9%) were from the European Union (EU)-Western Europe area. The most studied topic was the implant/abutment design/treatment of the surface (19.1%). Clinical research articles accounted for 92.99% of the publications, of which cross-sectional observational studies prevailed (21.7%). The presence of articles from the United States of America-Canada and EU-Western Europe was positively correlated with the impact factor. This study revealed an increasing trend in Asian research production, particularly Chinese, whereas production of European origin showed a decrease. Clinical studies increased their relative weight to the detriment of translational ones. A growing tendency in the relative weights of female authors was appreciated. Journal citations were associated with certain study variables.

Core Synergies Measured with Ultrasound in Subjects with Chronic Non-Specific Low Back Pain and Healthy Subjects: A Systematic Review.

Low back pain represents the leading cause of disability since 1990. In 90% of cases, it is classified as non-specific low back pain, being chronic in 10% of subjects. Ultrasound has proven to be an effective measurement tool to observe changes in the activity and morphology of the abdominal muscles. This article reviews which core synergies are studied with ultrasound in healthy subjects and with chronic non-specific low back pain. A systematic review was conducted on studies analyzing synergies between two or more core muscles. Publications from 2005 until July 2021 were identified by performing structured searched in Pubmed/MEDLINE, PEDro and WOS. Fifteen studies were eligible for the final systematic review. A total of 56% of the studies established synergies between the core muscles and 44% between the homo and contralateral sides of the core muscles. The most studied core synergies were transversus abdominis, internal oblique and external oblique followed by the rectus abdominis and the lumbar multifidus. No studies establishing synergies with diaphragm and pelvic floor were found. Eight studies were conducted in healthy subjects, five studies in subjects with chronic non-specific low back pain compared to healthy subjects and two studies in subjects with chronic non-specific low back pain.

Selective generation of gold nanostructures mediated by flavo-enzymes to develop optical biosensors.

This paper explores, for the first time, the use of flavo-enzymes for the enzymatic generation of gold nanomaterials. It has been demonstrated that when the oxidation of glucose by GOx is carried out in the presence of Au(III), the in-situ formation of gold nanomaterials is observed. Moreover, depending on the experimental conditions, either nanoparticles (AuNPs) or nanoclusters (AuNCs) are better observed, whose spectroscopical properties can be related to the concentration of glucose. Working at pH 6, only AuNCs with fluorescence at 420 nm (λex=335 nm) are obtained (linear relationship from 6.0·10-5 M to 1.5·10-3 M glucose). However, when the enzymatic reaction is performed at pH 8, AuNPs (λmax=580 nm) are also obtained (linear relationship from 5.5·10-4 M to 2.0·10-3 M glucose). Mathematical equations describing the variation of fluorescence and absorbance values during the reaction have been proposed. The results obtained suggest that AuNCs are formed using GOx as nucleation seeds. Since AuNPs belong to the branched-type, it is suggested that they are obtained by AuNC coalescence. From these models the AuNP molar absorptivity per atom was obtained (2.0(±0.3)·103 M-1cm-1). Finally, the method has been applied to the determination of glucose in orange juice and human plasma samples. Comparing the results with the GOx/HRP/TMB method and a commercial glucometer, no significant differences (P=0.05) are obtained.

Open science practices in general and internal medicine journals, an observational study.

BACKGROUND: As part of the Open Science movement, this study aims to analyze the current state of open access and open data policies concerning the availability of articles and raw data of the journals belonging to the category "Medicine, General & Internal" of the Science Citation Index Expanded. METHODS: Journal data sharing policies were evaluated through the following variables: possibility of manuscript storage in repositories; reuse policy; publication on a website; and statement regarding complementary material. Subsequently, an analysis of the supplementary material associated with each article was performed through the PubMed Central repository. The study reported was assessed following the STROBE guidelines for observational studies. RESULTS: This study shows that only one-third of the journals included in the category "Medicine, General & Internal" allow the depositing of their documents in repositories and its reuse, while approximately half of the journals agree to publish the document on a website as well as to deposit supplementary material along with the publication. However, the reality about this last variable is that only 9.5% of the articles analyzed contained supplementary material being the main journals involved, BMJ Open, JAMA Network Open, New England Journal of Medicine, Lancet and Plos Medicine. CONCLUSIONS: The analysis of the opening policies of the journals concerning data availability in medical research reveals the unequal positioning of publishers towards the sharing of open data, the ambiguity regarding government policies about the obligation to deposit data and the need for ethical and standardization requirements in the typology/format of the data deposited without forgetting the important role that the researcher plays. Further studies based on journals indexed in medical databases other than Science Citation Index Expanded are needed.

Unplanned molar intrusion after Invisalign treatment.

INTRODUCTION: The objectives of this study were to analyze and quantify molar intrusion after the use of clear aligners and to analyze the relationship with other variables such as age, duration of treatment, and a series of cephalometric osseous and dental measurements at the start of treatment. METHODS: A retrospective descriptive-analytical study was designed with a sample of 58 patients aged 18-60 years who had undergone treatment with Invisalign. The cephalometric measurements were carried out after lateral x-rays were taken of the cranium; these were compared at the start (T0) and conclusion of treatment. Parametric and nonparametric tests were used to compare means, whereas Pearson correlations and multivariate lineal regression analyses were used to establish the variables associated with molar intrusion. RESULTS: Approximately 74.2% of the patients presented some degree of molar intrusion after treatment. Furthermore, 32.8% of patients presented intrusion only at the mandibular molar, whereas 25.9% experienced intrusion at both molars, maxillary and mandibular, simultaneously. However, 15.5% presented intrusion only at the maxillary molar. The average magnitude of intrusion here was 0.98 ± 0.54 mm, whereas the mandibular molar was 0.84 ± 0.29 mm. Statistically significant reductions exist for the distance L6_MP and U6_SN between T0 and at conclusion of treatment. Maxillary molar intrusion correlates negatively with mandibular molar intrusion (r = -0.270). The number of days of treatment did not correlate with either maxillary or mandibular molar intrusion. CONCLUSIONS: Clear aligners give rise to molar intrusion in 74.2% of patients. The cephalometric variables L6_MP T0, mandibular plane angle T0, and facial axis T0 were negatively and significantly associated with maxillary molar intrusion, whereas age and facial axis T0 were negatively associated with mandibular molar intrusion allowing smaller magnitudes of intrusion to be predicted when these variables present high values at T0.

Effectiveness of removable appliances with temperature sensors in orthodontic patients: a systematic review and meta-analysis.

BACKGROUND/OBJECTIVE: Patient compliance during orthodontic treatment is one of the factors that most affects success in the final result. The use of removable appliances is frequent at an early age and the monitoring of its use is essential to assess the collaboration of the patient. The aim of this study was to establish the effectiveness of microsensors included in removable appliances during orthodontic treatment or in the retention phase to enable a reliable and individualized follow-up of the patient. SEARCH METHODS: The article search was carried out in various electronic databases and journals without any language restrictions. SELECTION CRITERIA: Studies using microsensors into removable appliances were selected with the key selection criterion of a minimum follow-up of 4 weeks. DATA COLLECTION AND ANALYSIS: The quality of the studies included was evaluated using the Cochrane scale for the randomized controlled trials and the Newcastle Ottawa Scale for control-case, cohort, and transversal studies. The mean of the differences with a 95% confidence interval was expressed for the continuous data. RESULTS: Twenty-nine full-text articles were analysed and included in the qualitative synthesis. In general, the mean daily wear time of removable appliances measured objectively was less than the time that the professional had predetermined. CONCLUSIONS: The use of microsensors as an objective measurement method enhances communication and boosts confidence in the orthodontist-patient relationship. More random clinical studies with temperature sensors are needed to establish to what extent they influence the orthodontic outcome. REGISTRATION: PROSPERO (CRD42019120525).

The LHC Olympics 2020 a community challenge for anomaly detection in high energy physics.

A new paradigm for data-driven, model-agnostic new physics searches at colliders is emerging, and aims to leverage recent breakthroughs in anomaly detection and machine learning. In order to develop and benchmark new anomaly detection methods within this framework, it is essential to have standard datasets. To this end, we have created the LHC Olympics 2020, a community challenge accompanied by a set of simulated collider events. Participants in these Olympics have developed their methods using an R&D dataset and then tested them on black boxes: datasets with an unknown anomaly (or not). Methods made use of modern machine learning tools and were based on unsupervised learning (autoencoders, generative adversarial networks, normalizing flows), weakly supervised learning, and semi-supervised learning. This paper will review the LHC Olympics 2020 challenge, including an overview of the competition, a description of methods deployed in the competition, lessons learned from the experience, and implications for data analyses with future datasets as well as future colliders.

Comparative Study of Oral Health-Related Quality of Life (OHRQL) between Different Types of Orthodontic Treatment.

Background and objectives: Although the main objective of any orthodontic treatment is to correct malocclusion, a range of psychosocial and/or esthetic factors drive patients to undergo orthodontic treatment. The aim of the present study was to analyze variations in oral health-related quality of life (OHRQL) levels in patients undergoing orthodontic treatment by means of four types of appliances: fixed buccal metal brackets, fixed buccal esthetic/ceramic brackets, fixed lingual brackets, and clear aligners. Material and Methods: The study sample comprised 120 patients aged 18 to 68 years who attended the Orthodontic department at the Dental Clinic of the University of Valencia. The Index of Orthodontic Treatment Need (IOTN) was used to measure orthodontic treatment need. Each patient completed three different intervals of the 14-item Oral Health Impact Profile (OHIP-14): before treatment (T0); six months after placing the orthodontic appliances (T1) and at the end of orthodontic treatment (T2). Results: All groups suffered a reduction in quality of life from T0 to T1 except the metal bracket group which presented the same level for the functional limitation domain (p = 1.000), the lingual bracket group for the psychological discomfort domain (p = 1.000) and clear aligner group for the physical disability domain (p = 0.118) and psychological disability domain (p = 1.000). Nevertheless, quality of life for most domains was similar in all groups at the end of treatment (T2). Conclusions: Patients underwent a significant reduction in quality of life during treatment in comparison with their pre-treatment condition but showed significant improvements at the end of treatment.

Nonsurgical treatment of an adult with skeletal Class III malocclusion, anterior crossbite, and an impacted canine.

Class III malocclusion presents some complexity in terms of diagnosis and treatment and affects not only the jaws but the whole craniofacial complex. Besides, functional forward displacement of the mandible may be diagnosed in a patient presenting Class III malocclusion, as the 2 entities are not incompatible or mutually exclusive. This case report describes the multidisciplinary, nonsurgical, orthodontic treatment of an adult patient with a skeletal Class III malocclusion, anterior crossbite, and a palatally impacted canine, treated with fixed appliances and skeletal anchorage. To upright the mandibular molars, distalize the whole mandibular arch, and avoid excessive inclination of maxillary incisors to improve dentofacial esthetics, miniscrews were placed in the retromolar area. The treatment results were very satisfactory and remained stable after a reasonable retention period.

One versus two anterior miniscrews for correcting upper incisor overbite and angulation: a retrospective comparative study.

BACKGROUND: Miniscrews are effective devices for performing upper incisor intrusion. Different mechanics can be applied depending on the treatment objectives. This study aimed to evaluate the efficacy of one or two anterior miniscrews for upper incisor correction in cases of overbite and angulation in adult patients. METHODS: Forty-four adults with deep overbite were divided into two groups: group 1 was treated with one miniscrew between upper central incisors and group 2 with two miniscrews between upper lateral incisors and canines. Incisor intrusion and length were measured from lateral cephalograms before treatment, after treatment and at least 12 months into retention (T0, T1 and T2). Forces were applied (90 g) from the miniscrews to the archwire using elastomeric chains. ANOVA analysis was used to determine whether differences between evaluation times were statistically significant. RESULTS: Mean root resorption was 2.15 ± 0.85 mm, which ceased after active treatment. Overbite mean correction was - 3.23 ± 1.73 mm with no statistically significant relapse. Overbite correction and incisor intrusion were significantly greater in group 2 (- 3.80 ± 1.43 versus - 2.75 ± 1.63 for OB and 8.19 ± 3.66 versus 5.69 ± 2.66 for intrusion). Resorption and overbite correction were positively related. No counterclockwise rotation of the mandibular plane was observed. CONCLUSIONS: Overbite correction can be performed by means of upper incisor intrusion without rotation of the mandibular plane. Correction of upper incisor intrusion and overbite is greater in patients treated with two miniscrews. The increase in upper incisor buccal angulation is greater with one miniscrew. Root resorption is positively related to the extent of intrusion. Stability is satisfactory regardless of whether one or two miniscrews are used.

Miniscrew mechanics for molar distalization and incisor intrusion in a patient with a Class II brachyfacial pattern and gummy smile.

A gummy smile is one of the most problematic characteristics in patients with a Class II Division 2 malocclusion, and the correction of vertical position and incisor torque is often challenging for the orthodontist. This case report describes the orthodontic treatment of a 31-year-old woman, assisted by miniscrew mechanics for maxillary arch distalization and correction of a gummy smile with a brachyfacial pattern. Two different mechanics were used. Miniscrews were placed in both maxillary tuberosities, and the maxillary arch was successfully distalized, correcting the Class II relationship. Interradicular miniscrews were placed for maxillary and mandibular incisor intrusion to correct the gummy smile, overbite, and torque. Finally, periodontal surgery was performed to lengthen the maxillary incisor crowns. Satisfactory smile esthetics and good occlusion were achieved. Follow-up after 24 months confirmed that the outcome was stable.

Antibody-Directed Synthesis of Catalytic Nanoclusters for Bioanalytical Assays.

Synthesis of atomic nanoclusters (NCs) using proteins as a scaffold has attracted great attention. Usually, the synthetic conditions for the synthesis of NCs stabilized with proteins require extreme pH values or temperature. These harsh reaction conditions cause the denaturation of the proteins and end up in the loss of their biological functions. Until now, there are no examples of the use of antibodies as NC stabilizers. In this work, we present the first method for the synthesis of catalytic NCs that uses antibodies for the stabilization of NCs. Anti-BSA IgG was used as a model to demonstrate that it is possible to use an antibody as a scaffold for the synthesis of semiconductor and metallic NCs with catalytic properties. The synthesis of antibodies modified with NCs is carried out under nondenaturing conditions, which do not affect the antibody structure. The resulting antibodies still maintain the affinity for target antigens and protein G. The catalytic properties of the anti-BSA IgG modified with NCs can be used to the quantification of bovine serum albumin (BSA) in a direct sandwich enzyme-linked immunosorbent assay (ELISA).

Risk factors for orthodontic mini-implants in skeletal anchorage biological stability: a systematic literature review and meta-analysis.

The reason of the biological stability loss of mini-implants is still a matter of discussion between dentistry professionals. The main objective of this systematic literature review and meta-analysis was to analyze the risk factors that prejudice this loss. A search was made in the electronic databases Pubmed, Scopus, Embase and Cochrane, in addition a manual search was made too in Grey Literature (Opengrey). No limits were set on the year of publication or language. The inclusion criteria were: studies in humans treated with fixed appliances with mini-implants, where the risk factors for secondary stability were evaluated for a minimum of 8 weeks. After eliminating duplicate studies and assessing which ones achieve the inclusion criteria, a total of 26 studies were selected for the qualitative synthesis, 18 of them were included in the quantitative synthesis. Common risk variables were compared in all of them. Analyzing the forest and funnel plots, statistically significant differences were obtained only for location, the upper maxilla having lower risk than the mandible with an odds ratio of 0.56 and confidence interval of 0.39 to 0.80. Prospective studies under controlled conditions should be required in order to obtain a correct assessment of the variables analyzed.

Antibacterial Properties of Nanoparticles in Dental Restorative Materials. A Systematic Review and Meta-Analysis.

Background and Objectives: Nanotechnology has become a significant area of research focused mainly on increasing the antibacterial and mechanical properties of dental materials. The aim of the present systematic review and meta-analysis was to examine and quantitatively analyze the current evidence for the addition of different nanoparticles into dental restorative materials, to determine whether their incorporation increases the antibacterial/antimicrobial properties of the materials. Materials and Methods: A literature search was performed in the Pubmed, Scopus, and Embase databases, up to December 2018, following PRISMA (Preferred Reporting Items for Systematic Review and Meta-Analysis) guidelines for systematic reviews and meta-analyses. Results: A total of 624 papers were identified in the initial search. After screening the texts and applying inclusion criteria, only 11 of these were selected for quantitative analysis. The incorporation of nanoparticles led to a significant increase (p-value <0.01) in the antibacterial capacity of all the dental materials synthesized in comparison with control materials. Conclusions: The incorporation of nanoparticles into dental restorative materials was a favorable option; the antibacterial activity of nanoparticle-modified dental materials was significantly higher compared with the original unmodified materials, TiO2 nanoparticles providing the greatest benefits. However, the high heterogeneity among the articles reviewed points to the need for further research and the application of standardized research protocols.

Effect of 2% Chlorhexidine Following Acid Etching on Microtensile Bond Strength of Resin Restorations: A Meta-Analysis.

Background and Objectives: The aim of this systematic review was to examine the effect of 2% chlorhexidine following acid etching on the microtensile bond strength of resin restorations for different follow-up times. Materials and Methods: A thorough search of PubMed, Scopus, and Embase databases were conducted. In vitro experimental studies or in vivo studies published up to December 2018 with an experimental group treated with a 2% chlorhexidine solution following acid etching and a control group were included, wherein the final restoration used a resin composite in both the groups. Results: Twenty-one articles were identified for qualitative analysis and 18 for meta-analysis. The difference in the means of microtensile bond strength between the two groups was calculated for the different follow-up times. The differences were significant for 6 months (4.30 MPa; 95% CI 2.72-5.89), 12 months (8.41 MPa; 95% CI 4.93-11.88), and 2-5 years including aged and thermocycling samples (9.08 MPa; 95% CI 5.36-12.81). There were no significant differences for the type of adhesive used. A meta-regression model showed a significant effect of time on the microtensile bond strength. Conclusions: The application of a 2% chlorhexidine solution after acid etching increased the microtensile bond strength significantly for follow-up times of 6 months or more. The adhesive type had no influence.