To assess the longevity of prefabricated versus conventional band and loop space maintainers in children with prematurely lost first primary molars.

A Randomized Clinical Trial

When considering gingival health and cement dissolution, does the longevity of the prefabricated band and loop differ from the conventional band and loop constructed following the premature loss of the lower first primary molars?

The concept of preserving space after premature tooth loss has been recognized for over a century. Conventional appliances are used successfully as space maintainers, but some disadvantages like the need for at least two visits to deliver the appliance due to laboratory work, will definitely affect its role during the general anesthesia.

The prefabricated space maintainer requires only one visit as it is fitted into the patient's mouth at the clinic without needing the dental lab. This provides a good impact on apprehensive children as it reduces the number of visits and chairside time. Prefabricated space maintainers could be a new alternative to the conventional fixed space maintainers used in pediatric dentistry.

Inclusion Criteria:

• Patients having mandibular first deciduous molar indicated for extraction due to extensive coronal caries beyond possible repair, root caries and/or failed pulp therapy.
• Caries free, or restored mandibular second primary molars and deciduous canines on the side of the extraction maintained throughout the entire follow-up period.
• Children are classified as cooperative or potentially cooperative according to Wright's classification of child behavior.
• According to space analysis, available space is less than or equal to the needed space
• 1/3 to less than 2/3 of the root of the permanent successor is formed to the prematurely lost primary molars
• Children are mentally capable of communication.
• Children aged 4-6 years

Exclusion Criteria:

• Children with any parafunctional habits.
• Children with previous allergies to stainless steel.
• Permanent successors with 2/3 of its roots formed and space analysis does not indicate the fabrication of space maintainer.
• Parental refusal of participation.

Blinding will not be feasible neither for the operator nor the patient. As there are some differences in the clinical steps, the form of the appliances and number of needed visits.

Outcome assessor and Statistician will be blinded from the intervention and control not knowing which group represents which procedure.