Can't get databases or its objects with powershell
I found the answer in serverfault:

https://serverfault.com/questions/355014/sql-server-powershell-cannot-find-path-error

I have to run a script to properly load the Snapins in PowerShell:

#
# Add the SQL Server provider.
#

$ErrorActionPreference = "Stop"

$sqlpsreg="HKLM:\SOFTWARE\Microsoft\PowerShell\1\ShellIds\Microsoft.SqlServer.Management.PowerShell.sqlps"

if (Get-ChildItem $sqlpsreg -ErrorAction "SilentlyContinue")
{
    throw "SQL Server Provider is not installed."
}
else
{
    $item = Get-ItemProperty $sqlpsreg
    $sqlpsPath = [System.IO.Path]::GetDirectoryName($item.Path)
}


#
# Set mandatory variables for the SQL Server rovider
#
Set-Variable -scope Global -name SqlServerMaximumChildItems -Value 0
Set-Variable -scope Global -name SqlServerConnectionTimeout -Value 30
Set-Variable -scope Global -name SqlServerIncludeSystemObjects -Value $false
Set-Variable -scope Global -name SqlServerMaximumTabCompletion -Value 1000

#
# Load the snapins, type data, format data
#
Push-Location
cd $sqlpsPath
Add-PSSnapin SqlServerCmdletSnapin100
Add-PSSnapin SqlServerProviderSnapin100
Update-TypeData -PrependPath SQLProvider.Types.ps1xml 
update-FormatData -prependpath SQLProvider.Format.ps1xml 
Pop-Location


Once loaded I can list every object in that database instance