Dean carded 72 67 71 as Boston’s Jordan Wrisdale finished birdie-birdie to clinch his first EuroPro Tour title by a shot.
After bogeying the first on the final day Dean followed a birdie at five with an eagle three at the next having had two eagles in his second round.
His final-day back nine started with a dropped shot and he sandwiched further bogeys at 15 and 16 with birdies at 14 and 17.
Four of the former English men’s amateur champion’s top-10 finishes have seen him inside the top five, including two runner-up placings.
The Oaks’ James Walker (73 68 70) placed 12th at Caversham Heath, closing with a flawless card containing three birdies and no bogeys.
He had carded six birdies and an eagle in round two.
Moortown’s Nick McCarthy (68 71 73) will rue a costly end to his final round. He had accumulated five birdies, but four shots scattered in the last three holes denied him a share of fourth and plummeted him to 17th.
Shipley’s Will Whiteoak tied 33rd with scores of 74 69 72, eight places above Hull’s Steve Robins (68 74 76).