Evaluation of Cytotoxicity of 4-Hydroxycinnamic Acid Using Tetrazolium Bromide Assay and Zebrafish Embryotoxicity: An In-Vitro Study.

Aim This study aimed to evaluate the cytotoxicity of a novel compound, 4-hydroxycinnamic acid (4-HCA), with the help of a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and zebrafish embryotoxicity. Materials and methods In this in vitro study, MTT fibroblast assays using dental pulp stem cells, which were cultured in Modified Eagle's Medium or Dulbecco's Modified Eagle Medium, and zebrafish cytotoxicity and embryotoxicity were done to evaluate the cytotoxicity of the novel compound 4-HCA. The data was analyzed by plotting cell number versus absorbance, allowing quantitation of changes in cell proliferation. Results 4-HCA (40 µl) showed acceptable levels of cell viability according to the American Society for Testing and Materials standards. Cell viability is reduced with increased exposure time and concentrations of 4-HCA. Similarly, the cytotoxicity assessment in zebrafish (Danio rerio) showed an acceptable range of toxicity levels in embryonic stages used to evaluate the mortality rate of zebrafish embryos. Conclusion Considering the constraints of this research, it can be deduced that hydroxycinnamic acid at a concentration of 40 µl was non-toxic. The findings from the MTT assay indicated a correlation between the concentration and the toxicity of the compound. Likewise, the zebrafish test demonstrated minimal toxicological effects.

Real-World Evaluation of the Safety and Effectiveness of 2.3% Hypertonic Saline Soft Mist Spray for Sino-Nasal Symptoms.

Introduction and aims Mildly hypertonic saline is more effective in relieving symptoms of nasal congestion compared to placebo or isotonic saline. Recently, a unique device, delivering a soft mist of 2.3% hypertonic sea-salt saline (Nasoclear PureHaleTM; Zydus Healthcare Ltd., India) has been introduced in India. The device uses a power-less manual technique to release the saline as a soft mist at 1 ml/min. Methods This is a retrospective, multi-centric, single-arm study to evaluate the safety and effectiveness of 2.3% hypertonic sea-salt saline nasal irrigation delivered through a soft mist device in patients with sino-nasal symptoms. This is an analysis of data of 130 patients collected from the medical records of 11 practicing pediatricians across India. Results The mean age of the patients was 5.23 ± 4.24 years; 63 % were boys and 37% were girls (n = 130). The mean reduction in total nasal symptom score (TNSS) at follow-up from baseline was 6.28 ± 0.18 (median days = 7) (95% CI = 5.92 to 6.64; p<0.0001; mean TNSS at baseline = 7.75 ± 2.01, mean TNSS at follow-up = 1.47± 1.30). Out of 130 patients, 33 patients (25.3%) showed complete improvement in TNSS, 93 patients (71.5%) had ≥ 50% improvement in TNSS while 4 patients (3.07%) showed <50% improvement in TNSS. The effectiveness of the device was rated as excellent (75%-100% improvement) and very good (50%-75% improvement) in 41 and 74 patients, respectively. It was rated as very easy to use and easy to use by 62 patients and 57 patients, respectively. One hundred nineteen patients (91.5%) were compliant with the prescribed frequency of the device and 110 patients (84.6%) were compliant with the prescribed duration of use of the device. No serious adverse events were reported; two patients reported mild side effects - stinging and irritation of the throat. Conclusions The 2.3% hypertonic sea-salt saline nasal irrigation delivered through the soft mist device was found to be well-tolerated and effective in patients with sino-nasal symptoms in real-world clinical settings. Clinical trial number The clinical trial number of this study is CTRI/2022/07/043751.

Vanillin-Mediated Green-Synthesised Silver Nanoparticles' Characterisation and Antimicrobial Activity: An In-Vitro Study.

Background and aim Nanoparticles in general due to their enhanced antimicrobial effects and other beneficial effects are used in dentistry. Silver nanoparticles (AgNPs) have emerged as the metal nanoparticle with the most advantages among the many types. The objective of the study was to synthesise vanillin-mediated AgNPs, then characterise those nanoparticles and assess their antimicrobial effectiveness. Materials and methods One-step synthesis of stable and crystalline AgNPs was done with vanillin as the reducing and capping agent. After being crushed into powder form, the produced AgNPs were subjected to characterisation. A scanning electron Microscope SEM) analysis was done for morphological details of the AgNPs. SEM with energy dispersive X-ray spectroscopy analysis (EDAX) and Fourier transform infrared (FTIR) testing were done for elemental analysis. AgNPs' antimicrobial properties were tested using the agar well diffusion technique. Results The SEM analysis revealed that the synthesized AgNps were porous and agglomerative clusters and varied in sizes between 30-35 nm. SEM-EDAX revealed the presence of 76.2 weight (wt)% Ag, 4.9 wt% carbon, and 18.9 wt% of oxygen. FTIR prominent peaks were observed at 1431.97 cm and 1361.20 cm indicating the presence of AgNPs. Both low and high concentrations of AgNps showed good antimicrobial effects against Streptococcus mutans (S. mutans). Conclusion Vanillin can be successfully used as a reducing agent for creating AgNPs. Due to their effective antimicrobial activity against S.mutans at various concentrations, vanillin-mediated AgNPs can be used with dental materials to reduce the risk of dental caries and enamel demineralization.

Synthesis and Characterization of the Zinc-Oxide: Tin-Oxide Nanoparticle Composite and Assessment of Its Antibacterial Activity: An In Vitro Study.

Introduction Nanoparticles (NPs) have been widely used for biomedical applications. Various methods of synthesis of NPs have been performed and the sol-gel technique is one of the most common and feasible methods. ZnO and SnO2 NPs are widely used due to their interesting properties and versatile medical applications. The present study aimed to synthesize a composite of ZnO- SnO2 NPs and evaluate its structural, morphological, and antibacterial properties. Materials and methods ZnO-SnO2 NPs were prepared via the sol-gel technique. The morphological study was performed by scanning electron microscopy (SEM) imaging, the structural study was performed by X-ray diffraction (XRD) analysis, and chemical studies were performed by Fourier transform infrared spectroscopy (FT-IR) and energy-dispersive X-ray spectroscopy (EDAX). Antibacterial properties of the NPs were assessed by the agar diffusion test and the area of bacterial growth that was inhibited was measured under high and low concentrations of the NPs. Results The SEM analysis confirmed the irregular shape and elemental composition of the synthesized NPs. The purity of the NPs was confirmed by the EDAX spectrum, which indicates the weight percentages of the elements in the NPs as follows: Sn-53.8%, Zn-12.5%, O-29.1%, and C-4.7%. The chemical bonds between the NPs were confirmed by Fourier transform infrared spectroscopy. XRD analysis confirmed the high degree of crystallinity of the NPs and orthorhombic structure of SnO2 and the hexagonal structure of ZnO. The zone of inhibition against S. aureus, S. mutans, and E. coli for low concentrations of the NPs was 24 mm, 26 mm, and 30 mm and for high concentrations of the NPs it was 26 mm, 28 mm, and 31mm and these values were similar to the control antibiotics.  Conclusion ZnO- SnO2 NPs were successfully prepared by the sol-gel method. The presence of NPs was confirmed and successfully characterized. The prepared NPs had a good antimicrobial effect against the tested pathogens.

The Synthesis, Characterization, and Assessment of Antibacterial Properties of an Orthodontic Adhesive Containing Cerium-Substituted Hydroxyapatite Nanoparticles: An In Vitro Study.

Introduction White spot lesions (WSLs) are early enamel caries lesions often seen in individuals receiving fixed orthodontic treatment. These lesions occur due to the buildup of plaque and the colonization of bacteria. WSL formation can be prevented by adequate oral hygiene measures and by the incorporation of antimicrobial nanoparticles (NPs) in orthodontic appliances and bonding systems. The aim of this research was to synthesize cerium-substituted hydroxyapatite nanoparticles (Ce-HAp NPs), characterize them, and assess their antimicrobial activity. Materials and methods This in vitro investigation involved the preparation of Ce-HAp NPs using the co-precipitation method, followed by their characterization using scanning electron microscope (SEM), energy-dispersive X-ray (EDAX), and Fourier transform infrared (FTIR). The NPs were prepared and subsequently added to an orthodontic adhesive. Antibacterial testing was conducted using the disc diffusion method against common oral pathogens (Staphylococcus aureus, Lactobacillus acidophilus, and Streptococcus mutans). The zones of inhibition were measured for two different concentrations of the adhesive. Results  The Ce-HAp NPs were successfully prepared and had an irregular agglomerated shape, measuring 63 nm in size. The major characteristic chemical groups of Ce-HAp were PO43-, OH-, and CO32-, and it was confirmed by the FTIR spectrum. The EDAX results of the synthesized NPs showed theoretical weight percentages (Wt%) of O, 52.6%; Ca, 20.9%; P, 11.8%; C, 10.3%; and Ce, 4.3%. A higher concentration of 40 µg/mL (30 mm for S. aureus and L. acidophilus and 25 mm for S. mutans) showed good antibacterial activity against the tested bacterial strains, compared to control antibiotics. Conclusion Cerium oxide (CeO2)-HAp NPs were prepared and incorporated into an orthodontic adhesive. The prepared adhesive exhibited effective antibacterial activity against prevalent oral pathogens.

Anti-quorum Sensing of Terminalia catappa and Murraya koenigii Against Streptococcus mutans.

Introduction Dental biofilm constitutes micro-organisms existing in an intercellular matrix containing organic and inorganic materials derived from saliva, gingival crevicular fluid, and bacterial products. Dental plaque biofilm inhibition by certain herbs and medicinal plants has been used as a treatment modality for the prevention of white spot lesions in orthodontic subjects. The aim of this study was to evaluate the anti-quorum sensing and anti-biofilm activity of Terminalia catappa and Murraya koenigiiagainst Streptococcus mutans. Materials and methods Samples of dental plaque were taken from patients receiving orthodontic care. The colonies of the S. mutans were isolated and biochemical characterization was done. Leaf extracts of Terminalia catappa and Murraya koenigii were used in the study. Methanolic extracts were subjected to evaluation of minimum inhibitory concentration (MIC) using the broth microdilution (two-fold) method and anti-biofilm activity using the crystal violet staining method. Results  The MIC of methanol leaf extracts of Murraya koenigii against S. mutans was noted at 0.62 mg/ml and Terminalia catappa at 1.25 mg/ml. At the lowest concentration of 0.03 mg and 0.01 mg methanol extract of Murraya koenigii had remarkably inhibited biofilm formation of 57.6% and 43.6% against S. mutans, respectively. Terminalia catappa leaf extracts did not show any anti-biofilm activity when the organisms were grown in the presence of S. mutans. Conclusion  Both Murraya koenigii and Terminalia catappa had antibacterial effects against S. mutans and Murray koenigii remarkably inhibited biofilm formation by S. mutans.

Evaluation of Antimicrobial and Mechanical Properties of a Novel Propolis-Modified Orthodontic Primer: An In-Vitro Study.

Introduction Accumulation of cariogenic biofilm around the bracket surface and the enamel adhesive interface leads to the formation of white spot lesions which poses an arduous challenge in orthodontics today. The aim of this study was to do a comparative evaluation of the antimicrobial, cytotoxic and mechanical properties of a novel propolis-modified orthodontic primer with a control primer. Materials and methods This in-vitro study involved two groups (group A: propolis-modified primer and group B: control primer). Antibacterial properties against Streptococcus mutans were evaluated using the agar well diffusion technique to measure the zone of inhibition and mic was evaluated using the two-fold diffusion technique. 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide (MTT) fibroblast assay was done to evaluate the cytotoxicity. After bonding brackets on extracted natural teeth (premolars) the shear bond strength (SBS), contact angle (CA) and adhesive remnant index (ARI) were evaluated for both groups. Statistical analysis was done using Statistical Package for the Social Sciences (IBM SPSS Statistics for Windows, IBM Corp., Version 23.0, Armonk, NY), and an independent t-test was performed. Results The propolis-modified primer when compared to the control primer had higher zone of inhibition values and lower minimum inhibitory concentration (MIC) values. The MTT fibroblast assay showed that the cell viability % shown by the propolis primer was more than the control primer. There was no statistically significant difference between the two primers for SBS (p>0.05), CA (p>0.05) and ARI (p>0.05) (p=0.05). Conclusion The propolis-modified primer showed higher antibacterial activity against S. mutans at a lower inhibitory concentration, with less cytotoxicity and no effect on the SBS, CA and ARI scores.

Inhibition of Quorum Sensing Controlled Virulence Factors and Biofilm Formation of Streptococcus mutans Isolated From Orthodontic Subjects by 4-Hydroxycinnamic Acid.

Introduction Dental plaque biofilms are a collection of microorganisms that are adhered to the tooth enamel surface. Inhibition of plaque biofilms is required to prevent dental caries and periodontitis and currently, there are many chemical and herbal products in use for inhibition of biofilms but with limited success. Materials and methods Dental plaque collection was done from subjects undergoing orthodontic therapy followed by isolation of Streptococcus mutans. Isolated S. mutans were subjected to disk diffusion assay with 4-HCA (baseline 10mg/mL) for the zone of inhibition and broth micro-dilution to evaluate the minimum inhibitory concentration (MIC) and sub-MIC. Crystal violet staining was done for biofilm inhibition assay. Results Growth of S. mutans was inhibited by 4-HCA at concentrations as low as 0.31 mg/mL. 4-HCA (40µL) inhibited the bacterial growth and a clear zone (15 mm) was observed. 4-Hydroxycinnamic acids treated culture showed progressive reduction in the biofilm production at the concentration of 0.01 mg/mL. The 4-HCA concentration as low as 4 mg and 2 mg has remarkably inhibited biofilm formation of 49.3% and 34.3%, respectively. Conclusion The anti-quorum sensing and anti-biofilm activity of 4-Hydroxycinnamic acid against S. mutans isolated from subjects undergoing orthodontic treatment showed a remarkable result.

Dentoalveolar and Soft Tissue Changes Following en-Masse Anterior Retraction With Different Force Vectors in Subjects With Bidental Protrusion: A Retrospective Evaluation.

Introduction The aim of the study is to determine the effects of different vertical force vectors acting on dentoalveolar and soft tissues while applying a retraction force using various anchorage sources and their effects on these tissues. Material and methods Based on the selection criteria, a total of 35 patient case records with Angle's Class I bidental malocclusion and incompetent lips treated with four premolar extractions were included. Retraction was achieved using a NiTi coil spring with two different force vectors. The anchorage in group 1 was enhanced by a transpalatal arch (TPA) and Lower Stabilizing Arch (LSA) in the upper and lower arch, respectively, with a force vector parallel to the occlusal plane, whereas in group 2, the force vector using Temporary Anchorage Devices (TADs) was 15 - 20 degrees to the occlusal plane. The skeletal, dental, and soft tissue were obtained using 40 parameters. Intra-group comparisons between pre- and post-treatment records were conducted using a paired t-test, while inter-group comparisons were conducted using an independent t-test. Result Significant anchor loss was observed in group 1, indicated by mesial movement of molar crowns by (-2.10±0.50) in the maxillary arch and (-1.75±0.38) in the mandibular arch. Distal movement of incisors following premolar extractions with both studied force vectors resulted in an improvement in lip procumbency and incisor inclinations, without any significant skeletal changes. Molar mesial movement was observed in subjects treated with conventional anchorage. Conclusion En masse anterior retraction did lead to anchorage loss when carried out without TADs. Altering the force vector did not produce significant changes in tooth movement along the vertical plane.

The Correlation of a Novel Photographic Parameter for Facial Profile Assessment in Subjects With Different Sagittal Malocclusions: A Prospective Study.

Aim The soft tissue paradigm shift is the current trend in orthodontic diagnosis and treatment planning. This study's aim was to assess the correlation of newly derived photographic Frankfort horizontal plane-subnasale to soft tissue pogonion (FSA) angle with other established soft tissue cephalometric angles, such as the Z angle and the Holdaway (H) angle, for estimating facial profile convexity in subjects with all classes of sagittal malocclusions. Materials and methods This prospective study included a sample of 60 Dravidian population subjects consisting of 30 males and 30 females with different skeletal sagittal malocclusions (Class I, Class II, and Class III) based on the radiographic criteria (ANB angle). The Z and Holdaway angles on lateral cephalograms were compared with the FSA angles in cephalograms and digital profile photographs. Statistical analysis was done using the Statistical Package for Social Sciences (SPSS) software version 23.0 (IBM SPSS Statistics, Armonk, NY). Pearson's correlation was done to assess the correlation between soft tissue FSA angle on digital photographs and cephalometric angle (Z angle and Holdaway angle). Results The overall Pearson's correlation was significant (p < 0.05) between the Z and FSA angles in Class I, II, and III malocclusions, which had a high positive correlation. There was a significant positive correlation (p < 0.05) between the Holdaway and FSA angles in subjects with Class I and Class II malocclusions. A moderate positive correlation was noted between the Holdaway and FSA angles in Class III. Conclusion Photographic FSA angle can be used to evaluate the facial profile of subjects with different sagittal malocclusions. This angle has a good correlation with other cephalometric profile measures, such as the Z and Holdaway angles used to assess facial profile convexity.

Photographic Frankfort plane subnasale pogonion (FSA) angle for assessment of anteroposterior discrepancies in malocclusion subjects: A prospective study.

INTRODUCTION: Anterior-posterior discrepancy assessment is a crucial component of orthodontic diagnosis and is often carried out using hard tissue cephalometric analysis. The purpose of this study was to compare the photographic Frankfort plane subnasale pogonion (FSA) angle with established cephalometric parameters to determine the accuracy of the angle in determining maxillomandibular anteroposterior discrepancies. MATERIALS AND METHODS: In this prospective study, a total of 60 subjects, 20 in each skeletal sagittal malocclusion, were included in the final sample based on the selection criteria. Both photographic and cephalometric records were taken, and the parameters assessed were the beta angle, Steiner's analysis, the ANB (A point- Nasion- B point) angle in the cephalograms, and the FSA angle in the profile photographs. Statistical analysis was done with SPSS software. The correlation between the measured parameters was assessed using Pearson's correlation test. RESULTS: A high positive and significant correlation between the FSA angle and beta angle (r = 0.793) was noted, and a high negative and significant correlation between the FSA angle and ANB angle (r = -0.848) was noted. CONCLUSION: The photographic FSA angle can be used as a reliable parameter to diagnose anteroposterior discrepancies.

Electromyographic Assessment of the Masseter and Temporalis Muscles in Skeletal II Malocclusion Subjects With Varying Overjets: A Pilot Study.

Introduction Class II malocclusions are commonly associated with some muscle disharmony and imbalance. Diagnosis of muscle imbalance helps in treating the malocclusion as well as preventing relapse of the treatment. The aim of this study is to compare the muscle activity of masseter and temporalis in patients with skeletal Class II division 1 malocclusion with varying overjet using surface electromyography (sEMG). Materials and methods Ten subjects in the age range 18-35 years with skeletal Class II malocclusion and varying overjets who required orthodontic treatment were included in this study. Out of these 10 patients, five of them had a 2-4mm overjet and the other five had an overjet >4mm. A four-channel sEMG system was used to conduct the sEMG of muscles. Muscle activity, synergy, and symmetry of masseter and temporalis muscles were assessed and compared between the two groups with an Independent t-test. Results There were no significant differences in the muscle activities of the temporalis and masseter muscles in both groups. Symmetry and synergy of these muscles in the two groups also showed no significant difference (p>0.05) at rest and clenching. However, during chewing, the masseter muscle showed poor balance and activity. Conclusion The overjet in Class II division 1 malocclusions did not seem to affect the muscle activity at rest and during clenching. In patients with increased overjet, during chewing, masseter activity in terms of intensity and balance was poor.

Comparative Assessment of Bracket Bond Failure Rates of a Novel Chitosan-Based Orthodontic Primer: An In Vivo Split-Mouth Study.

Introduction An unavoidable side effect of orthodontic fixed appliance therapy is the demineralization of the enamel surface surrounding the bracket at the adhesive and tooth interface due to a microgap formation, which serves as a nidus for biofilm growth. Due to this, it is advantageous to include antibacterial agents in orthodontic primers without affecting their clinical properties. The aim of this study was to compare the in vivo bracket bond failure rates of a novel chitosan-based primer with a conventional orthodontic primer. Materials and methods Fifty-four subjects and 1,080 brackets were included in this study. At the end of six months, 45 subjects and 960 brackets bonded using novel chitosan-based primers and conventional primers (Anabond, Anabond Stedman Pharma Research Pvt Ltd, Chennai, India). Each was evaluated for a bracketed bond failure rate. Descriptive statistics and Chi-square tests were used for statistical analysis. Results The results revealed that the bracket bond failure rate in Group 1 (novel chitosan-based primer) was 27 brackets (3%) and 23 brackets in Group 2 (conventional primer) (2.5%), with no statistically significant difference between the two groups (p>0.05). There was a statistically significant difference in the bracket failure rate between the maxillary arch (2%) and the mandibular arch (3.5%) (p<0.05). Conclusion Brackets bonded with the chitosan-modified novel orthodontic primer showed no statistically significant difference in bracket bond failure rate when compared to the conventional primer. Bond failure rates were higher in the mandibular teeth when compared to the maxillary teeth.

Gingerol and Chitosan-Based Coating of Thermoformed Orthodontic Aligners: Characterization, Assessment of Anti-Microbial Activity, and Scratch Resistance: An In Vitro Study.

Aim To prepare and characterize a 6-gingerol-incorporated chitosan biopolymer for coating on thermoformed aligners and evaluate its scratch resistance and antimicrobial activity. Material and methods In this in vitro study, 6-gingerol extract was prepared, incorporated with chitosan biopolymer into a coating solution and characterized using nuclear magnetic resonance imaging spectroscopy (NMR). Twenty thermoformed aligner samples were exposed to UV radiation for surface activation, then coated with a crosslinking agent. These were divided into four groups of five. The control group consisted of samples dip-coated in a chitosan solution for 15 minutes. The three test groups consisted of samples dip coated in a gingerol-chitosan coating solution, with each group representing the following time periods of dip coating: five, 10, and 15 minutes. The crosslinking of the coating with the aligner material was confirmed by a Fourier transform infrared spectroscopy (FTIR) test. A scratch test was carried out to evaluate the wear resistance of the coating, and the antibacterial properties of the coating were tested using a Disc Diffusion test. Results The NMR analysis confirmed the presence of 6-gingerol in the extract. The coating of 6-Gingerol on aligners was confirmed by FTIR spectroscopy. The wear resistance of aligners coated for 5 minutes, 10 minutes, and 15 minutes was 1.8 ± 0.09 N, 2.3 ± 0.021 N, and 3.06 ± 0.17 N, respectively, and the difference was statistically significant (p<0.05). The aligner coated for 15 minutes exhibited the widest zone of inhibition of up to 2.38 ± 0.44 mm against Streptococcus mutans, and the difference was statistically significant (p<0.05).​​​​​​ No antibacterial effect was found against E. Coli. Conclusion A novel coating material with 6-gingerol extract incorporated in chitosan biopolymer was prepared and characterized, followed by coating on thermoformed aligners. The coating showed antibacterial activity against Streptococcus mutans, and both the antimicrobial activity and wear resistance increased with coating duration.

Comparative evaluation of bracket bond failure rates of a novel non-primer adhesive with a conventional primer-based orthodontic adhesive - a pilot study.

Background: Bonding is an important step in fixed orthodontic therapy and evaluation of bracket bond failures while using different bonding systems is required. The aim of the present study was to evaluate and compare bracket failure rates of a novel no primer adhesive with conventional primer-based orthodontic adhesives. Methods: This split mouth study was conducted among fifteen patients who underwent therapy with fixed orthodontic appliances using metal brackets. Total of 300 brackets were bonded and the bracket bond failure rates were assessed at the end of 3 months. The difference in bond failure rates between the two groups were assessed in different teeth. Descriptive statistics and chi-square test was performed. Results: Evaluation of bracket bond failure rates showed a higher incidence of bond failures in the group bonded with the primerless adhesive (6.3%) compared to conventional adhesive (2.3%) but there was no statistically significant difference (P>0.05). No intergroup difference was found in the bracket failure rates of individual teeth (P>0.05). Conclusion: Higher incidence of bond failures were noted with brackets bonded with primerless adhesive when compared to primer-based adhesive but no significant difference was noted over a period of 3 months. Mandibular canine and premolars had a higher bracket failure rate with no significant difference between the adhesives.

Effects of titanium oxide coating on the antimicrobial properties, surface characteristics, and cytotoxicity of orthodontic brackets - A systematic review and meta analysis of in-vitro studies.

Objective: The objective of this review is to systematically analyze the available literature on the effects of titanium oxide (TiO2) coating on the antimicrobial properties, surface characteristics, and cytotoxicity of orthodontic brackets. Methods: In-vitro studies reporting on the effects of Titanium oxide (TiO2) coatings on antimicrobial properties, surface roughness, cytotoxic activity and bacterial adhesion of orthodontic brackets were included in the review. Electronic databases such as PubMed, SCOPUS, Web of Science and Google Scholar, were searched till September 2022. Risk of Bias was analyzed by using RoBDEMAT tool. Meta-analysis using Random Effects Model was performed for assessing the antimicrobial activity against S. mutans, C. albicans and L. Acidophilus. Results: A total of 11 studies were included the RoB analysis revealed sufficient reporting across all the domains and inconsistent reporting in only two of the domains. On qualitative analysis, a significant antimicrobial effect of TiO2 coating on orthodontic brackets against Streptococcus mutans, Candida albicans and Lactobacillus acidophilus was reported. The meta analysis revealed a significant overall antimicrobial effect with a high heterogeneity. (SMD: 3.5; p < 0.00001; i2 - 99.2%). Conclusion: An overall significant antimicrobial effect of TiO2 coated brackets against S. mutans, L. Acidophilus, C. Albicans was noted but with a high heterogeneity. The subgroup analysis revealed a significant antimicrobial effect on C albicans with a low heterogeneity but it was limited by a publication bias. The included studies reported reduced surface roughness, minimal bacterial adhesion and less cytotoxic activity with TiO2 coated brackets than uncoated brackets.

Dentoalveolar and Airway Changes Following En Masse Distal Movement of the Maxillary Dentition with Infrazygomatic Crest Anchorage: A Prospective Study.

Aims and Objectives: Mini screws placed buccal to the maxillary first or second molars in the infra zygomatic crest (IZC) region can be used as anchors for various types of tooth movement. En masse distal movement of the maxillary dentition with IZC anchorage is routinely practiced nowadays as more patients demand a non-extraction treatment and it should be evaluated. The goal of this study was to assess dentoalveolar and airway changes in individuals with class II malocclusion after en masse distal movement of the maxillary dentition utilizing infrazygomatic anchorage. Materials and Methods: This prospective study included patients who required en masse distal movement of the maxillary dentition. Following initial leveling and aligning, mini screws were placed in the IZC region, and the maxillary arch was distalized en-masse. Pre (T0) and post distalization (T1) lateral cephalograms were traced for dentoalveolar and airway changes. Statistical tests were done with SPSS software. Shapiro-Wilk test for normality and paired T test for comparison between before and after en masse distalization were done. Results: The changes in dental angular and linear measurements such as U1 to N-A, L1 to N-B and interincisal angle, U1 to N-A and U1 to point A distance, U1 to palatal plane, L1 to N-B, L1 to Apo line distance, U6 to PtV were statistically significant (P > 0.05). Linear parameters such as L1 to ApO line, upper airway, and lower airway were not statistically significant (<0.05). Conclusion: Class II div I malocclusions can be efficiently corrected without extractions using IZC anchorage by en masse distal movement of the maxillary dentition. Significant reduction in upper anterior inclination, intrusion of maxillary anterior teeth, and distal movement of the posterior teeth were noted. No changes in airway dimensions were noted.

Influence of Operator Experience on Scanning Time and Accuracy with Two Different Intraoral Scanners - A Prospective Clinical Trial.

Objective: Operator experience and scanner type may influence the time taken and obtained accuracy of intraoral scanning. This study aimed to evaluate the influence of operator experience on the scanning time and correlate the accuracy of the scans taken with two different intraoral scanners (TRIOS 3, 3Shape and i500, Medit). Methods: In this trial, a total of 20 subjects who required intraoral scanning for orthodontic treatment were included. Intraoral scanning was done with two different scanners, TRIOS 3 and i500. One operator each with high (group 1), medium (group 2) and low (group 3) levels of experience performed intra-oral scanning with two different intraoral scanners. A One-Way ANOVA test was performed to assess the intergroup difference in scanning time and Kendall's tau's correlation test to determine the correlation between the experience of the operator and accuracy among the three groups using the two scanners. Also Independent samples t-test were performed to assess the intragroup differences in scanning time with two different scanners. Results: The scanning time was influenced by the type of intraoral scanner and operator experience (p<0.05). No significant correlation between operator experience and scanning accuracy in the three groups was noted (p>0.05). Statistically significant intragroup differences in scanning time between the two scanners were noted (p<0.05). Conclusion: Less experienced operators took more time to scan a subject. Accuracy of scanning among three groups using two scanners was not influenced by the experience of the operator. Scanning with i500 IOS took more time than TRIOS.

Prevalence and extent of Alveolar dehiscence and fenestration in Class I hyperdivergent subjects with different buccolingual inclinations of maxillary molar teeth: a CBCT study

Buccolingual position of teeth could affect the prevalence of alveolar bone defects. Presence of alveolar defects may have a deleterious effect on orthodontic treatment. The aim was to assess the prevalence and extent of dehiscence and fenestration in Class I hyperdivergent subjects and correlate it with buccolingual inclinations(BL) of maxillary first molar teeth. Methods: This retrospective study involved 80 CBCTs of class I hyperdivergent subjects divided into two groups - group A (n=33) buccolingual inclination >9º and group B (n=47) buccolingual inclination <9º. Prevalence and extent of alveolar bone dehiscence and fenestrations were measured in CBCTs using OSIRIX Lite software. Descriptive statistics, Mann Whitney U test and Spearman correlation were done for evaluating intergroup differences and correlation with Buccolingual inclination. Results: Overall prevalence of dehiscence and fenestration in maxillary first molars was 60.95% and 5% respectively. In the buccal alveolar bone, prevalence of dehiscence was highest in group A (84.6%) for 16 and in the lingual alveolar bone prevalence of dehiscence was highest in group B (71.4%) for 26 . On intergroup comparison, the extent of lingual alveolar bone dehiscence (26) in group B was significantly higher (p value <0.05) than in group A. No significant correlation between the extent of dehiscence and fenestration with buccolingual inclination of molar teeth was noted. Conclusion: Molar teeth with BL inclinations of more than 9º had higher prevalence of dehiscence on the buccal side and molar teeth with BL inclinations less than 9 degrees had more dehiscence on the lingual side. But no significant correlation of BL inclination with prevalence and extent of dehiscence and fenestration was noted

Occlusal Contact Surface Changes and Occlusal Force Distribution Between Vacuum-Formed Retainers and Other Retainers: A Systematic Review.

The present systematic review was done to assess the available literatures on changes in the number of occlusal contacts (NOC), occlusal contact surface areas, and occlusal force distribution (OFD) with vacuum-formed retainers (VFRs) or clear overlay retainers during retention and to compare them with other retainers. Six electronic databases (Web of Science, Scopus, PubMed, Cochrane Library, Lilacs, and Google Scholar) were searched. Randomized controlled trials (RCTs) and controlled clinical trials (CCTs) reporting on occlusal contact changes with VFRs were included. A total of nine articles were included in this review: three RCTs, five prospective controlled trials (PCTs), and one CCT. The Cochrane risk of bias tool and ROBINS-I tool were used for risk of bias assessment. The three RCTs showed moderate risk of bias, and out of five CCTs, four showed low risk of bias, and one showed moderate risk of bias. One CCT showed a low risk of bias in the ROBINS-I tool. Two out of four studies reported improved occlusal surface area (OSA) with VFRs when assessed at the end of six months and 12 months; one out of four studies reported improved NOC; and one study reported a decrease in OFD anteriorly and an increase in OFD posteriorly after two months of retention. On comparison between the groups, the other retainer groups showed more NOCs compared to VFRs. The limited available evidence suggests an increase in OSA and no change in NOCs and OFD with VFRs during retention. No significant differences between VFRs and other retainers for OSA and OFD were noted, and more NOCs were noted for other retainer groups.