Comparison of Root Resorption, Microbial Colonization & Gingival Health Between Clear Aligners, Self-Ligating Brackets & Conventional Brackets- A Randomized Controlled Clinical Trial

Importance of the research Orthodontic treatment is no longer limited mainly to children and adolescents. With increasing number of patients from older age groups seeking orthodontic treatment; there has been an increasing demand for esthetic alternatives to conventional fixed stainless steel appliances. Some issues associated with conventional fixed appliances for treatment are: 1) unaesthetic appearance of brackets especially for adult patients, many of whom are unwilling to wear braces, 2) conventional systems compromise the ability of the patient to maintain good oral hygiene; 3) increase the risk of periodontal breakdown due to constant accumulation of plaque around the brackets, wires and ill-fitting bands; 4) require many follow-up visits for appliance reactivation and adjustment if the teeth do not move as desired; 5) iatrogenic root resorption, a major medico-legal concern also poses significant problems for the clinician. Increased use of self-ligating brackets and clear aligners from Invisalign (Align Technology, Inc., Santa Clara, CA) are some of the recent developments in orthodontics that have tried to address these concerns. However clinical evidence highlighting their efficacy has not been quiet forthcoming. Present knowledge is primarily based upon case reports, case series, surveys, anecdotal reports and retrospective studies. In such a scenario it is imperative to find an optimized evidence-based treatment strategy that leads to predictable outcome with complete patient satisfaction during and after treatment while minimizing the risk for root resorption and periodontal breakdown.

RESEARCH DESIGN & METHODS:

Screening procedure:The partcipants were selected from the Division of Orthodontics, Department of Craniofacial Sciences, University of Connecticut, Health Center by two investigators: 1) faculty member supervising the 'clinical component' of the research and 2) faculty member supervising the microbiological and radiological part of the research.

Only after gaining approval from both the faculty members a participant was selected for the study. The participants and their parents were provided with a written explanation on the background of the study, its objectives, and their involvement. In addition to the consent form for routine orthodontic care currently used in the investigator's clinic; the patient or parent/guardian of every participant was given a second consent form specifically related to this study. The following were the inclusion criteria, which were based on previous studies and the investigator's clinical research experience:

1. All the participants should be physically healthy with no relevant allergies or medical problems.
2. All participants ≥ 12 years of age.
3. There should be less than 8mm of anterior crowding or spacing and adequate buccal interdigitation. Patients with posterior edentulous spaces will only be included if treatment does not entail space closure.
4. Participants should have all permanent teeth present, except third molars.
5. Demonstrable ability to maintain adequate oral hygiene.
6. Show optimum dental health without immediate need for restorations.