ABSTRACT
BACKGROUND: Extraction of premolars and retracting the anterior teeth using mini-implants and anterior retraction hooks became advent now a day. In such treatments, consolidation of arches is not done in regular practice. So, the present study is concentrated on effects of consolidation in two implant and three implant combinations of retraction and intrusion. METHODS: A three-dimensional FEM model of maxillary teeth and periodontal ligament housed in the alveolar bone with the first premolars extracted is generated with appropriate number of elements and nodes. The models were broadly divided into two groups according to the no. of implants. Mini-implants were placed bilaterally between the second premolar and molar at varying heights (7, 10, 13 mm) in group I, and along with bilateral implants, an additional mid-implant is placed between the central incisors as group II. Brackets with 0.022 slot were placed on the teeth, 19 × 25 SS wire is placed in the brackets, an anterior retraction hook was placed at 9 mm height, and analysis was done to evaluate the stresses and displacement patterns in consolidation and non-consolidation models. RESULTS: The results showed that consolidation of the anterior teeth during intrusion and retraction shows various advantages such as less stresses on the bone, PDL, implant, teeth, and no labial flaring of the anterior teeth and three implant system, i.e., two bilateral implant at 10 mm and a mid-implant at 12 mm between the centrals has shown to be better than other models as bodily movement is observed. CONCLUSION: Consolidation is better than non consolidation during enmasse retraction and intrusion.
Subject(s)
Orthodontic Anchorage Procedures/instrumentation , Tooth Movement Techniques/instrumentation , Dental Implantation/methods , Dental Implants , Finite Element Analysis , Humans , Incisor , Models, Dental , Orthodontic Anchorage Procedures/methods , Tooth Movement Techniques/methodsABSTRACT
OBJECTIVES: The present study was conducted to compare the cleaning efficacy (debris and smear layer removal) of hand and two NiTi rotary instrumentation systems (K3 and ProTaper). MATERIALS AND METHODS: Sixty single rooted human maxillary anterior teeth decoronated at the cementoenamel junction were used. All the specimens were divided into four groups of 15 teeth each, group I--ProTaper rotary instrumentation done, group II--K3 rotary instrumentation done, group III--Stainless steel K-file instrumentation done, group IV--root canal irrigation without instrumentation. Root canal preparation was done in a crown down manner and 3% sodium hypochlorite was used as irrigant after each file followed by final rinse with 5 ml of 17% EDTA solution, then specimens were scanning electron microscopic (SEM) examination. RESULTS: Statistical analysis was done using one-way ANOVA followed by post hoc Tukey's HSD test. Group I showed highly statistical significant difference compared to other groups. There was no statistically significant difference considering smear layer at any levels among the groups with no smear layer formation in group IV. CONCLUSION: ProTaper rotary instrumentation showed the maximum cleaning efficacy followed by K3 rotary instrumentation in the coronal, middle and apical thirds of the root canal. CLINICAL SIGNIFICANCE: ProTaper rotary instruments are more efficient than hand and K3 rotary instruments during root canal treatment.
