Among molar tubes and molar bands used as terminal attachments in fixed orthodontic appliances, which provides better clinical outcomes in terms of attachment success rate, periodontal health and patient's perception in adolescent patients?"

Study setting: Orthodontic unit, Lady Ridgeway Hospital for Children, Colombo, Sri Lanka. Methods of randomisation: simple randomisation. Allocation: Group 1- molar bands in right upper permanent first molar and molar tubes in left lower permanent first molar and opposite in other quadrants. Group 2: molar tubes in right upper permanent first molar and molar bands to left lower permanent first molar and opposite will be done in other quadrants. Procedure that both groups will undergo: The first molars to receive bands will be placed separators for one week and following which the bands will be cemented using glass ionomer cement available in orthodontic unit. Molar bands with McLaughlin, Bennett, and Trevisi (MBT) prescription will be chosen for all first molars which will be bonded. Prior to fixing the attachments both groups will be asked to brush their teeth. The teeth to receive tubes will be isolated with cotton rolls and saliva ejector. 37% orthophosphoric acid etchant will be applied for 15 seconds, then rinsed and dried. Primer will be applied and molar tubes with MBT prescription of upper first molar and lower first molars will be bonded. The same commercial brand of glass ionomer cement and composite will be used for all patients following the manufacturer instructions and one operator will perform all the clinical steps. The remainder of teeth will be bonded with MBT brackets and initial arch wires will be placed immediately after bonding other teeth and followed their routine orthodontic treatment procedures. o The Bleeding of probing, calculus and periodontal health will be assessed preoperatively , 6th month , 12th month. o All patients will be given the same oral hygiene instructions and dietary instructions. o The bond or cement failure leading to attachment loosening or breakage will be regarded as failure. o The success or failure of molar band or tube will be documented with the tooth number along with the details of patient on the review appointment. At the same visit, the tooth will be banded or bonded again based on the assigned group, and the treatment will continue routinely. o Patient perception questionnaire will be administered by independent trained dental surgeon who is not involved in cementing molar band or bonding molar tube or outcome assessment to reduce response bias at 6th month All patients will receive standardized oral hygiene and dietary instructions at the baseline visit and during follow-up appointments. Compliance with oral hygiene instructions will be assessed subjectively, and reinforcement will be provided at each visit to ensure adherence to the recommended oral care practices.

• Age: between 12-18 years for both sexes • Fully erupted permanent dentition having all teeth except third molars • Patients requiring fixed appliance in both arches • Patients having both extraction and non-extraction treatment protocols • Patients with stable mental health who can maintain good oral hygiene and maintain safety of brackets

• Patients with missing or extracted or planned extraction of any of the first permanent molars • Patients having first permanent molars with evidence of demineralization, caries, and developmental enamel defects • Patients with any buccal restorations in first permanent molars with amalgam /composite /glass ionomer cements/ crowns that may interfere with banding or bonding. • Patients having poor oral hygiene and evidence of periodontal disease exhibiting pocket depth more than or equal to 4mm, bleeding on probing score more than or equal to 30 % of sites, visible supragingival or subgingival calculus on examination. • Patients having malocclusions that could predispose to debonding bonded tubes such as severe deep bite, unilateral or bilateral posterior crossbite and severe crowding (> 8mm arch discrepancy • Patients who require extra oral and intra oral anchorage appliances in addition to fixed appliance such as head gear, transpalatal arches and temporary anchorage devices • Patients who need expansion of their arches using quad helix for correction of transverse discrepancy • Patients with craniofacial anomalies