Methods: Twenty-two patients (11 males and 11 females; mean age 19.18 ± 2.00 years) having Angle's Class II division 1 malocclusion needing bilateral extractions of maxillary first bicuspids were recruited for this split-mouth randomized clinical trial. After the initial stage of alignment and leveling with contemporary edgewise MBT (McLaughlin-Bennett-Trevisi) prescription brackets (Ortho Organizers, Carlsbad, Calif) of 22 mil, followed by extractions of premolars bilaterally, 6 mm nickel-titanium spring was used to retract the canines separately by applying 150 g force on 0.019 × 0.025-in stainless steel working archwires. LIPUS (1.1 MHz frequency and 30 mW/cm2 intensity output) was applied for 20 minutes extraorally and reapplied after 3 weeks for 2 more successive visits over the root of maxillary canine on the experimental side whereas the other side was placebo. A numerical rating scale- (NRS-) based questionnaire was given to the patients on each visit to record their weekly pain experience. Impressions were also made at each visit before the application of LIPUS (T1, T2, and T3). Models were scanned with a CAD/CAM scanner (Planmeca, Helsinki, Finland). Mann-Whitney U test was applied for comparison of canine movement and pain intensity between both the groups.
Results: No significant difference in the rate of canine movement was found among the experimental (0.90 mm ± 0.33 mm) and placebo groups (0.81 mm ± 0.32 mm). There was no difference in pain reduction between experimental and placebo groups (p > 0.05).
Conclusion: Single-dose application of LIPUS at 3-week intervals is ineffective in stimulating the OTM and reducing associated treatment pain.
Materials and Methods: Twenty patients with Angle's class II div 1 (10 males and 10 females; aged 20.25 ± 3.88 years) needing bilateral extractions of maxillary first bicuspids were recruited. Conventional brackets MBT of 0.022 in slot (McLaughlin Bennett Trevisi) prescription braces (Ortho Organizers, Carlsbad, Calif) were bonded. After alignment and levelling phase, cuspid retraction began with nitinol closed coil spring on 19 × 25 stainless steel archwire, wielding 150 gram force. 7.5 J/cm2 energy was applied on 10 points (5 buccal and 5 palatal) on the canine roots on the investigational side using gallium-aluminum-arsenic diode laser (940 nm wavelength, iLase™ Biolase, Irvine, USA) in a continuous mode. Target tissues were irradiated once in three weeks for 9 weeks at a stretch (T0, T1, and T2). Patients were given a feedback form based on the numeric rating scale (NRS) to record the pain intensity for a week. Silicon impressions preceded the coil activation at each visit (T0, T1, T2, and T3), and the casts obtained were scanned with the Planmeca CAD/CAM™ (Helsinki, Finland) scanner.
Results: The regimen effectively accelerated (1.55 ± 0.25 mm) tooth movement with a significant reduction in distress on the investigational side as compared to the placebo side (94 ± 0.25 mm) (p < 0.05).
Conclusions: This study reveals that the thrice-weekly LLLT application can accelerate OTM and reduce the associated pain.
METHODS: Twenty-two patients (11 male, 11 female; mean age, 19.8 ± 3.1 years) with Angle Class II Division 1 malocclusion were recruited for this split-mouth clinical trial; they required extraction of maxillary first premolars bilaterally. After leveling and alignment with self-ligating brackets (SmartClip SL3; 3M Unitek, St Paul, Minn), a 150-g force was applied to retract the canines bilaterally using 6-mm nickel-titanium closed-coil springs on 0.019 x 0.025-in stainless steel archwires. A gallium-aluminum-arsenic diode laser (iLas; Biolase, Irvine, Calif) with a wavelength of 940 nm in a continuous mode (energy density, 7.5 J/cm2/point; diameter of optical fiber tip, 0.04 cm2) was applied at 5 points buccally and palatally around the canine roots on the experimental side; the other side was designated as the placebo. Laser irradiation was applied at baseline and then repeated after 3 weeks for 2 more consecutive follow-up visits. Questionnaires based on the numeric rating scale were given to the patients to record their pain intensity for 1 week. Impressions were made at each visit before the application of irradiation at baseline and the 3 visits. Models were scanned with a CAD/CAM scanner (Planmeca, Helsinki, Finland).
RESULTS: Canine retraction was significantly greater (1.60 ± 0.38 mm) on the experimental side compared with the placebo side (0.79 ± 0.35 mm) (P <0.05). Pain was significantly less on the experimental side only on the first day after application of LLLI and at the second visit (1.4 ± 0.82 and 1.4 ± 0.64) compared with the placebo sides (2.2 ± 0.41 and 2.4 ± 1.53).
CONCLUSIONS: Low-level laser irradiation applied at 3-week intervals can accelerate orthodontic tooth movement and reduce the pain associated with it.
METHODOLOGY: Three sodium-fluoride(NaF) concentration(0.01%w/v,0.1%w/v and 0.5%w/v respectively)and two poly-γ-glutamic acid(PGGA)concentration(1%w/v and 2%w/v respectively)were prepared in 0.1 M acetic acid(pH4.0)and deionized distilled water.For de/re-mineralisation study, tooth samples (18 teeth varnished, leaving a 2 mm2 window on the mid-buccal surfaces) were immersed in respective acidified NaF and PGGA solutions. The Ca2+ release/uptake was monitored with ISE over 72-hr with increasing pH every 24-h from 4.0 to 6.0.These teeth were later subjected to cross-sectional microhardness to determine integrated mineral recovery of enamel on increasing pH of respective acidified solution.In order to determine mechanism of PGGA,two concentrations of PGGA in deionized-water-solutions were used for tooth samples immersion followed by overnight drying then later subjected to Fourier Transform Infra-Red(FT-IR) analysis.The FT-IR analysis was also carried out on PGGA powder.For control,the experiment was repeated using hydroxyapatite(HAp)pellets.The density of PGGA solutions(1%and2%)was also measured to determine their dynamic viscosities.
RESULTS: The ISE and microhardness testing revealed statistically significant (ρ ≤ 0.05) dissolution inhibition and remineralisation potential for tooth sample treated with acidified 2%PGGA. From the FT-IR spectra, it was observed that the profiles of the enamel and HAp surfaces treated with 1%-and 2%-PGGA solutions were similar to those of PGGA powder.It was found that the viscosity of PGGA increases with increasing concentration.
CONCLUSION: The study implies that 2% PGGA is more effective than NaF as forms a coating layer to protect from demineralisation and promote remineralisation of the tooth surface.
METHODS: This systematic review was undertaken following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The protocol has been registered with the International Prospective Register of Systematic Reviews (number CRD42019127021). A comprehensive literature search was performed by 2 independent reviewers using a selected search strategy in 2 electronic databases (PubMed and Scopus) until January 28, 2019. A further search was performed manually in endodontic journals. Studies investigating or comparing at least 1 shaping property resulting from root canal instrumentation with a glide path or preflaring in human extracted teeth or clinical studies were included.
RESULTS: The literature shows that the definition of glide path and preflaring procedures remains controversial, which requires an elaboration in the American Association of Endodontists' Glossary of Endodontic Terms. After the removal of irrelevant and duplicated articles, 98 articles were included. The impact of glide path preparation and preflaring on working length determination, apical file size determination, canal transportation, separation of endodontic files, shaping time, dentinal microcrack formation, and extrusion of debris was discussed. Because of heterogeneity among the included studies, quantitative synthesis was not performed for most of the parameters.
CONCLUSIONS: An evidence-based guideline is needed to define and correlate the basic concepts and current applications of each step of contemporary advancements in root canal instruments. Glide path preparation reduces the risk of debris extrusion, has no influence on the incidence of dentinal crack formation, and improves the preservation of the original canal anatomy. The creation of a glide path may have no impact on Reciproc files (VDW, Munich, Germany) in reaching the full working length. Preflaring increases the accuracy of working length determination. Further randomized clinical trials are required to evaluate the effect of a glide path and preflaring on root canal treatment outcomes.
Objectives: The main aim of the study was to determine and compare the erosive potential of different fruit juices in frozen/unfrozen forms on primary teeth by studying the calcium dissolution.
Materials and methods: pH of four different juices (pure) - apple, orange, citrus limetta (musumbi) and grapes were determined using a digital pH meter. The titratable acidity of these in frozen and unfrozen forms were determined by adding 0.2 ml of 1M NaOH to these to raise to pH=5.5(critical pH) and pH =7(neutral pH). Forty eight caries free deciduous anterior teeth specimens were prepared to study the calcium dissolution by atomic absorption spectrophotometer. The results were analysed for statistical significance using One-way Repeated Measures ANOVA and pair wise multiple comparison with Bonferroni correction.
Results: Total titratable acidity and calcium dissolution were found to be significantly more in the initial thawed fruit juices.
Conclusion: Frozen fruit juices had more buffering capacity and erosive potential than unfrozen forms. The study concluded that sucking on frozen fruit juices is more damaging to teeth than unfrozen forms because more of erosion is expected to occur in a frozen state.