Here’s a Powershell script that can be used to manage index fragmentation in SQL Server databases. The strategy I’ve used in the script is based on a recommendation from Pinal Dave (blog twitter) in his article  Difference Between Index Rebuild and Index Reorganize Explained with T-SQL Script. Just set the $sqlserver and $database variables to something appropriate for your environment. Enjoy!
# Load SMO
[System.Reflection.Assembly]::LoadWithPartialName('Microsoft.SqlServer.SMO') | Out-Null;

# Set sql server and database name here
$sqlserver = "localhost\sql2005";
$database = "AdventureWorks";

$srv = New-Object "Microsoft.SqlServer.Management.SMO.Server" $sqlserver;
$db = New-Object ("Microsoft.SqlServer.Management.SMO.Database");
$db = $srv.Databases[$database];

# Get table count
$table_count = $db.Tables.Count;
$i = 0;

# First script out the drops
foreach($table in $db.Tables)
	Write-Progress -Activity "Checking table $table" -PercentComplete (($i / $table_count) * 100) -Status "Processing indexes" -Id 1;
	foreach($index in $table.Indexes)
		$index_name = $index.Name;
		Write-Progress -Activity "Checking table $table" -PercentComplete (($i / $table_count) * 100) -Status "Processing index $index_name" -Id 1;
		# Get the fragmentation stats
		$frag_stats = $index.EnumFragmentation();

		# Get the properties we need to work with the index
		$frag_stats | ForEach-Object {
						$Index_Name = $_.Index_Name;
						$Index_Type = $_.Index_Type;
						$Average_Fragmentation = $_.AverageFragmentation;
		Write-Host -ForegroundColor Green "$Index_Type $Index_Name has a fragmentation percentage of $Average_Fragmentation";

		# Here we decide what to do based on the level on fragmentation
		if ($Average_Fragmentation -gt 40.00)
			Write-Host -ForegroundColor Red "$Index_Name is more than 40% fragmented and will be rebuilt.";
			Write-Host -ForegroundColor Green "$Index_Name has been rebuilt.";
		elseif($Average_Fragmentation -ge 10.00 -and $Average_Fragmentation -le 40.00)
			Write-Host -ForegroundColor Red "$Index_Name is between 10-40% fragmented and will be reorganized.";
			Write-Host -ForegroundColor Green "$Index_Name has been reorganized.";
			Write-Host -ForegroundColor Red "$Index_Name is healthy, with $Average_Fragmentation% fragmentation, and will be left alone.";

Write-Progress -Activity "Finished processing `"$database`" indexes." -PercentComplete 100 -Status "Done" -Id 1;
Start-Sleep -Seconds 2;

AdventureWork Index Management with Powershell