What can you guess about a man who makes his wife chocolate truffles and then sends her off to brush her teeth once she's finished eating them? Well, if you said that he must be working in the field of dentistry, and is enough of a romantic to set aside the fact that sugar plays havoc on her teeth, and is a pretty good cook on top of it all, you'd be right on all three counts.

"He tries to balance my sweet tooth," said Diana Winters Guttenberg of her husband, Steven Guttenberg, an oral surgeon, "but he's got a lot on his hands when he tries to do that." She's had a chocolate habit ever since she can remember and has never been able to get it under control.

Actually it's a good balance -- she gets her truffles and clean teeth, and he gets to spend time in the kitchen at his favorite hobby.

"I really don't feel guilty giving them to her, as long as she brushes her teeth after she eats them," said Steven Guttenberg. "Anyway, saliva gets rid of most of the sugar from truffles, and gum is much worse for you."

Though time constraints will force this accomplished cook to buy chocolate truffles for his wife for tomorrow night's St. Valentine's Day celebration, he'll still be in the kitchen putting his energy into heart-shaped tomato pasta to surround saute'ed shrimp tossed in a double-reduced wine and cream sauce. "The truth is, we celebrate Valentine's Day every day of the year," Steven Guttenberg said. "You can tell by the heart-shaped pasta that I'm a hopeless romantic."

He'll shape the pasta while she makes the salad (her only kitchen chore in the two years they've been married). Then together they'll enjoy belon oysters on the half shell and sip dry martinis. She selected the belon oysters for the menu in memory of the first time she fell in love with raw oysters, New Year's Day, l983. Though they'd known each other for almost 10 years prior, when their daughters were in nursery school together, "it was our first real serious date," he said, "the day we started going steady you might say. I ordered them and she fell in love." They were married four months later.

The children will already have gone to bed by the time they sip martinis, and they'll have the entire evening alone. When they finally sit down to a candlelit, flowery table, there will be champagne with the shrimp and pasta, and a salad to follow. For dessert, more champagne and all the chocolate truffles she has room for.

"Cooking is my escape," he said. "I enjoy cutting up vegetables rather than using the Cuisinart." When 17 house guests showed up over this past Christmas holiday, he met the challenge with platters of homemade jambalaya one night, sushi another, and dim sum yet another. He reads cooking magazines as other oral surgeons read the Journal of the American Dietetic Association (JADA), and has four shelves of cookbooks for quick reference on a kitchen wall. He teaches his friends to cook, "all in the spirit of socializing," and has a big reputation for his homemade pizza and pasta creations. "People give me cooking things for gifts," he laughed.

Diana Guttenberg, a practicing attorney at Children's Hospital, says she realized the seriousness of his passion for cooking while holed away in a room studying for the bar exam in 1983. "You could hear him down in the kitchen listening to the radio, singing and dancing. "He was having a great time," she said, "and he knew it too. I haven't cooked since we were married, and I certainly don't feel deprived. Just to watch him cook is enough for me," she said.

She doesn't want to give away what she'll be giving him for Valentine's Day this year, but it's a tossup between a piece of art and some flowers. One thing she knows he won't be getting is a box of chocolates. She tried that last year and they remained untouched by the bed for at least a month before the whole family started eating them. "He just doesn't have a sweet tooth," she said. But then she quickly took it back, "Well, if his sweet tooth ever pops up he'll sit down and eat a whole box . . . and then go brush his teeth." SAUTEED SHRIMP IN WINE AND CREAM SAUCE WITH HEART-SHAPED PASTA (2 generous servings) 1 pound large shrimp Flour for dredging 1 stick (8 tablespoons) butter 12 mushrooms, sliced 2 scallions, finely chopped 2/3 cup dry white wine 2/3 cup whipping cream Juice of 1 lemon 1 teaspoon dry tarragon Salt and white pepper to taste Heart-shaped pasta (recipe follows) Peel, devein, wash and dry shrimp. Lightly flour shrimp. Saute' shrimp in melted butter for 2-3 minutes. Add mushrooms and scallions and saute' 1 more minute. Remove shrimp only (cover to keep warm), add wine and reduce sauce until consistency of a light syrup. Add cream and reduce again until thickened. Replace shrimp. Add lemon juice, tarragon and salt and pepper to taste. Simmer 1-2 minutes longer, just to warm the shrimp. Serve on warmed plates surrounded by heart-shaped pasta. HEART-SHAPED TOMATO PASTA 1 large egg 3/4 to 1 cup semolina flour 1 tablespoon tomato paste (substitute pureed beets for redder pasta) 2 tablespoons butter

Process egg, flour and tomato paste in the bowl of a food processor fitted with a metal blade until a moist ball of dough is formed. If the mixture seems too dry or not red enough, add more tomato paste; if too wet, add a little more flour. Let sit 10 minutes.

Either roll out dough by hand to about 1/8 inch, or by machine to next-to-thinnest setting. (If the pasta begins to tear, stop at the second-to-thinnest setting.)

Using 3/4- or 1-inch heart-shaped aspic or jelly cutter, stamp out dough hearts. These can be either left to dry to use immediately or placed in the freezer for a quick lunch or dinner at some later date.

To cook, place the hearts in a large pot of salted, boiling water. The pasta is ready when the water reboils. Drain in a colander and toss with 2 tablespoons of butter. Place on warmed serving plates and cover center of plate with the saute'ed shrimp.