Simple Data Access Layer

I have DatabaseContext class.

public interface IDatabaseContext : IDisposable
{
    SqlConnection Connection { get; }
}

public class DatabaseContext : IDatabaseContext
{
    private readonly string _connectionString;
    private SqlConnection _connection;

    public DatabaseContext(string connectionString)
    {
        _connectionString = connectionString;
    }

    public SqlConnection Connection
    {
        get
        {
            if (_connection == null)
                _connection = new SqlConnection(_connectionString);

            if (_connection.State != ConnectionState.Open)
                _connection.Open();

            return _connection;
        }
    }

    public void Dispose()
    {
        if (_connection != null && _connection.State == ConnectionState.Open)
            _connection.Close();
    }
}

And I use it in PageService class using dependency injection, for example:

public class PageService
    {
        private readonly IDatabaseContext _databaseContext;

        public PageService(IDatabaseContext databaseContext)
        {
            _databaseContext = databaseContext;
        }

        public IEnumerable<CustomPage> GetAllPages()
        {
            IEnumerable<CustomPage> pages;
            using (var db = _databaseContext)
            {
                //using Dapper.Net to get list of pages.
                pages = db.Connection.GetList<CustomPage>();
            }
            return pages;
        }
    }

Do you see any improvement / issue of my DatabaseContext class?