## 3 Results
### Meta-Analysis  
#### 3.3.1 Marginal Bone Loss  
Taking into account the diverse range of subjects, research backgrounds, and research periods, a random-effects model was employed. Furthermore, the high level of \(l^{2}\) values (87%; \(p<0.01\)) indicated substantial heterogeneity among the studies. To account for this heterogeneity, a subgroup analysis was performed, dividing the literature into four subgroups based on the loading time frame: 1 year, 3 years, 5 years, and 10 years. Given the considerable heterogeneity among the studies, the between-study variance was not assumed to be equal in the meta-ANOVA analysis (Version 3.5.0; R Project for Statistical Computing). A total of twelve articles ([PERSON] et al., 2021 [12]; [PERSON] et al., 2019 [13]; [PERSON] et al., 2018 [14]; [PERSON] et al., 2017 [15]; [PERSON] et al., 2017 [16]; [PERSON] et al., 2017 [17]; [PERSON] et al., 2016 [18]; [PERSON] et al., 2014 [19]; [PERSON] et al., 2012 [22]; [PERSON] et al., 2014 [20]; [PERSON] et al., 2013 [21]; [PERSON] et al., 2012 [23]) examined the differences  
Figure 2: Risk of bias. (**A**) Summary of the risk of bias in the included studies [12; 13; 14; 15; 16; 17; 18; 19; 20; 21; 22; 23]. (**B**) Overall risk-of-bias score for each field. in MBL between PS implants and PM implants. The forest plots (Figure 3) depict the consolidated data. The results of the meta-analysis demonstrated that the pooled MD for reducing MBL in PS implants compared with PM implants was \(-0.60\) (95% CI, \(-0.91\) to \(-0.28\); \(p<0.01\)). The overall test for effect was significant (\(p<0.01\)), and it revealed that there were significant differences among the subgroups (\(p=0.01\)). One Year after Loading  
Nine included articles ([PERSON] et al., 2019 [13]; [PERSON] et al., 2018 [14]; [PERSON] et al., 2017 [15]; [PERSON] et al., 2017 [16]; [PERSON] et al., 2016 [18]; [PERSON] et al., 2014 [20]; [PERSON] et al., 2013 [21]; [PERSON] et al., 2012 [22]; [PERSON] et al., 2012 [23]) evaluated the differences in MBL between press-fit (PS) and parallel-walled (PM) implants one year after loading. A high level of heterogeneity (\(p=89\%\); \(p<0.01\)) was observed among the studies. The meta-analysis results showed that the pooled mean difference in MBL reduction between PS and PM implants was \(-0.70\) (95% CI, \(-1.16\) to \(-0.25\); \(p<0.01\)). The forest plot favored PS implants with less MBL compared with PM implants (Figure 3). Three Years after Loading  
Three included articles ([PERSON] et al., 2019 [13]; [PERSON] et al., 2016 [18]; [PERSON] et al., 2014 [19]) examined the MBL differences between PS and PM implants three years after loading. The \(I^{2}\) values (30%; \(p=0.24\)) indicated low heterogeneity among the studies. The  
Figure 3: Forest plot illustrating the comparison between platform switching and platform matching for marginal bone loss on follow-up monitoring. meta-analysis results showed that the pooled mean difference in MBL reduction between PS and PM implants was \(-0.22\) (95% CI, \(-0.49\) to 0.55; \(p=0.11\)). The forest plot still favored PS implants with less MBL compared with PM implants (Figure 3). Five Years after Loading  
Three included articles ([PERSON] et al., 2021 [12]; [PERSON] et al., 2018 [14]; [PERSON] et al., 2017 [15]) assessed the differences of MBL between PS implants and PM implants 5 years after loading. A high level of the \(l^{2}\) values (91%; \(p<0.01\)) indicated significant heterogeneity among the studies. The results of the meta-analysis showed that the pooled MD of reducing MBL in PS implants compared with PM implants were \(-0.43\) (95% CI, \(-1.10\) to 0.23; \(p=0.20\)). The forest plot favors PS implants with less MBL compared with PM implants (Figure 3). Ten Years after Loading  
One included article ([PERSON] et al., 2017 [17]) assessed the differences of MBL between PS implants and PM implants 10 years after loading.