## 4 Discussion  
Atraumatic restorative treatment is one of the minimally invasive procedures for restoration of carious lesions, which is well received because of its atraumatic nature, and ease of instrumentation without provoking much anxiety, especially in children [29]. The present study was conducted to assess the influence of cavity size on the survival of conventional and CHX modified GIC in single surface primary molar teeth ART. The result showed a cumulative survival rate of all ART restorations after a two-year follow-up was 83.3%. The recent systematic review by [PERSON] et al. [23] showed survival of 94.3% for single surface posterior teeth ART with a 2-year follow-up. However, the systematic review used studies with conventional GIC. In the present study, both conventional, and CHX modified GIC was used. [PERSON] et al. [15] showed an overall survival of 48% in multiple surface primary teeth restoration for both conventional and CHX modified GIC after a 1-year follow-up. The current result showed no significant difference in the overall success of conventional (83.9%), and CHX modified GIC (82.7%) after 24 months follow-up. The result is in agreement with previous single and multiple surface ART restorations on primary and permanent teeth with conventional and CHX modified GIC [15; 18]. This suggests that the addition of CHX did not alter the physical properties of GIC [11; 14; 15]. In the present study, the survival percentage decreased with age from 6 months to 24 months in both groups. This may be attributed to the cumulative effects of dropouts and failure of restoration through the 2-year follow-up period. The cavity size plays an important role in the survival of restorations [15; 17]. In the present study, cavities with a volume of 10-19.9 mm\({}^{3}\) showed the highest survival both in conventional and CHX modified GIC. The smallest and largest restorations showed a relatively poor survival percentage. This may be due to deficiency in the material in the smallest restorations and bulk failure or pulpal reactions in the largest restorations [15]. With cavity depth, the highest success was observed with a cavity depth of 2.1-3 mm both in conventional and CHX modified GIC (\(p<0.05\)). At depth \(>\)3 mm, the survival percentage was high for CHX modified GIC. This may be due to the enhanced antimicrobial ability of CHX modified GIC, which reduced pulpal infection in deep cavities and chances of failure [10; 13]. Concerning buccolingual and mesiodistal width, the highest success was observed with a 2.1-3 mm width. High failure in the smallest and greatest width may be due to deficient material or bulk failure, respectively. In the present study, the survival of ART was assessed clinically, using ART restoration criteria with codes from 0 to 8 [28]. This criterion has the advantage of assessing the marginal integrity of the restoration [30]. The most successful restorations were assessed to \begin{table}
\begin{tabular}{c c c c c c c c c c c} \hline \hline
**Time Interval** & & & **GIC** & & & & & **CHX-GIC** & \\
**(Months)** & & **n**  & **n**  & **S** & **S** & **n**  & **S** & **S** \\ \hline
0-6 & 90 & 3 & 3 & 96.6 & 1.7 & 90 & 4 & 3 & 95.4 & 1.9 \\
6-12 & 86 & 8 & 4 & 90.7 & 2.1 & 86 & 9 & 4 & 89.5 & 2.3 \\
12-18 & 83 & 12 & 7 & 85.5 & 3.1 & 83 & 14 & 7 & 83.1 & 3.6 \\
18-24 & 81 & 13 & 9 & 83.9 & 3.8 & 81 & 14 & 9 & 82.7 & 3.9 \\ \hline \hline \end{tabular}  
\end{table} 
Table 7: Survival percentage with standard error for conventional and CHX modified GIC ART restoration at a different time interval. be in good condition (code-0) for both the groups, while the reason for failure was recorded maximum under gross marginal defect (code-3). This is in line with previous studies, which showed the main reason for failure was due to a marginal defect in restoration [15; 17; 18]. The strength of the present study is the standardized procedure used, where all the restorations were carried out by a single operator, under the rubber dam isolation method.