With an increasing number of adult patients coming to the orthodontic clinic, the orthodontic professional is constantly looking for ways to accelerate tooth movement. Surgical intervention to affect the alveolar housing and tooth movement has been described in various forms for over a hundred years. However, it is the spirit of interdisciplinary collaboration in orthodontics has expanded the realm of traditional orthodontic tooth movement protocols. Periodontal accelerated osteogenic orthodontics (PAOO) is a clinical procedure that combines selective alveolar corticotomy, particulate bone grafting, and the application of orthodontic forces. This procedure is theoretically based on the bone healing pattern known as the regional acceleratory phenomenon (RAP). PAOO results in an increase in alveolar bone width, shorter treatment time, increased post treatment stability, and decreased amount of apical root resorption. Tooth movement can be enhanced and cases completed with increased alveolar volume providing for a more intact periodontium, decreased need for extractions, degree of facial remodeling and increased bone support for teeth and overlying soft tissues, thereby augmenting gingival and facial esthetics.The purpose of this article is to describe the history, biology, clinical surgical procedures, indications, contraindications and possible complications of the PAOO procedure. Key words:Periodontics, corticotomy, osteogenic, orthodontics.

Aim:The purpose of this study was to evaluate the effect of phytic acid, ethylenediaminetetraacetic acid (EDTA), and chitosan solutions on the microhardness of human radicular dentin.Materials and Methods:Thirty dentin specimens were randomly divided into three groups of 10 specimens each according to the irrigant used: G1 — 1% phytic acid, G2 — 17% EDTA, and G3 — 0.2% chitosan. A standardized volume of each chelating solution was used for 3 min. Dentin microhardness was measured before and after application at the cervical, middle, and apical levels with a Vickers indenter under a 200-g load and a 10-s dwell time. The results were analyzed using one-way analysis of variance (ANOVA) and Student's t test.Results:Microhardness of the radicular dentin varied at the cervical, middle, and apical levels. EDTA had the greatest overall effect, causing a sharp percentage reduction in dentin microhardness with a significant difference from phytic acid and chitosan (P = 0.002). However, phytic acid and chitosan differed insignificantly from each other (P = 0.887).Conclusion:All tested chelating solutions reduced microhardness of the radicular dentin layer at all the levels. However, reduction was least at the apical level. EDTA caused more reduction in dentin microhardness than chitosan while phytic acid reduced the least.

Aim:To compare the effect of three root canal sealer activation techniques on percentage and depth of sealer penetration of MTA Fillapex and AH Plus sealers.Materials and Methods:Sixty teeth prepared till F5 ProTaper size were divided into three equal groups on the basis of sealer activation technique (G1: Ultrasonics, G2: Lentulo spiral, and G3: Counter-clockwise rotary motion). Each group was further divided into two equal subgroups on the basis of type of sealer used: AH Plus (Denstply, Konstanz, Germany) or MTA Fillapex (Angelus, Londrina, PR, Brazil) and obturated with gutta-percha. Horizontal sections at 3 and 6 mm from the apex were obtained and the percentage and depth of penetration of sealers into dentinal tubules were measured using confocal laser scanning microscopy (CLSM). Statistical analysis was performed utilizing Kruskal-Wallis and Mann-Whitney U tests with a significance level of 5%.Results:G1 showed significantly (P < 0.001) high percentage and depth of sealer penetration than G2 and G3 while the difference was insignificant (P > 0.05) between G2 and G3.Conclusion:Percentage and depth of sealer penetration are influenced by the type of sealer used sealer activation technique and by the root canal level. Ultrasonic method of sealer activation and MTA Fillapex showed the best results.

Aim: This study was conducted to evaluate and compare fluoride ion release by Cention-N (self-cure and light-cure) and conventional glass-ionomer cement (GIC) at different pH and time intervals. Methodology: Cavities of similar dimensions were prepared in mandibular molars and restored with Cention-N (by self-cure and light-cure techniques) and GIC. Samples were stored in deionized water, and the cumulative fluoride ion release and change in pH were assessed utilizing spectrophotometer and pH meter, respectively, at the end of 7 days, 14 days, and 21 days. The data thus obtained were statistically analyzed. Results: All the tested materials released fluoride ions in both acidic and neutral pH at all time intervals, and the fluoride ion release was significantly higher (<0.05) in acidic pH as compared to neutral pH except in GIC. All the groups showed a statistically significant increase in pH in acidic medium, whereas no significant increase was observed in neutral medium. Conclusions: Cention-N (self-cure) has the highest fluoride ion release and alkalizing potential in acidic pH as compared to Cention-N (light-cure) and GIC.

Introduction:This study evaluated the effect of root canal preparation, obturation, and different techniques of retreatment on the percentage increase in the number of dentinal microcracks using microcomputed tomography (CT) analysis.Materials and Methods:Forty-five mandibular premolars after micro-CT scanning were prepared using Protaper universal files up to F4 and obturated. After the second micro-CT scanning again, the samples were randomly divided into three groups (n = 15) for retreatment procedure. In Group 1, retreatment was done with Protaper universal D1, D2, and D3 retreatment files followed by Protaper universal file till F4. In Group 2, retreatment was performed with R-Endo reciprocating motion, Re, R1, R2, R3, and Rs followed by Hero Shaper size #40. In Group 3, retreatment was performed with H-files and xylene till size #40. After gutta percha removal, the samples were again scanned for micro-CT for the evaluation of percentage increase in dentinal microcracks. Data were analyzed using “Kruskal–Wallis test ANOVA” and “student t-test” at 5% level of significance.Results:Few unprepared samples showed preexisting microcracks. There were statistically significant percentage increase dentinal cracks after root canal preparation and obturation as well as after retreatment procedure with statistically significant percentage increase in the number of dentinal microcracks between all three groups.Conclusion:Intraradicular procedures such as shaping and cleaning and obturation as well as the use of retreatment file lead to the induction and propagation of dentinal microcracks. In the present study, the maximum microcracks were produced with Protaper universal retreatment file system followed by R-Endo system. H-files produced minimum cracks during retreatment procedures.