Different Designs of Space Maintainer

Purpose: Evaluation of survival rate for three space maintainers (SMs) of different designs versus standard one.

Methods: 52 extraction sites in children of age group of 4-7 years with prematurely-lost 1st primary molar were selected for this study. The whole sample was divided into four groups (13 each). In Group I, Band and loop (B&L), Group II: Single-sided band and loop (Ss B&L), Group III: Direct bonded wire (DBW), Group IV: Tube and loop (T&L). children were recalled at 3, 6, 9, 12,15-month. Cumulative survival rates of SMs were estimated by means of Kaplan-Meier method with log rank test. Cumulative survival rates of SMs were estimated by means of Kaplan-Meier method with log rank test. Sample size: The total sample size was calculated using Sampsize application with anticipated success on treatment with conventional band and loop 86% , anticipated response on treatment with direct bonded wire 33% 12, at 80% power, and significant level 0.05.

Inclusion criteria

• Children and their parents showed cooperation and compliance.
• Extraction of the first primary molar was not exceeding three months.
• Angle's class 1 occlusion with normal deciduous molar relation
• Child not complaining from any systemic disease.
• The extraction space was of only one missing first deciduous molar with remaining teeth present on mesial and distal side of extraction space.
• Absence of para-functional habits or abnormal occlusion conditions such as crossbite, open bite, deep bite.
• No restorative application on the buccal surfaces of abutment teeth, otherwise extra-coronal complete coverage, as stainless-steel crown, was applied only in banded groups.
• Radiographically, presence of permanent successor.
• Absence of any pathological evidence on the eruption track of the permanent tooth.
• Ability to attend follow-up appointments as required.

Exclusion criteria

• Child complaining from any systemic disease.
• Prescence of para-functional habits or abnormal occlusion conditions such as crossbite, open bite, deep bite
• Extraction of the first primary molar was exceeding three months.
• The extraction space resulted from more than one missing deciduous molar
• Radiographically, absence of permanent successor.