A Manhattan dentist who studied at NYU traded root canals for meth, peddled kiddie porn out of his practice in Chelsea — and “actively” engaged in underground bestiality parties, federal authorities charged.

John Wallace Wolf, 59, was busted Friday after a two-month probe by the FBI and Drug Enforcement Administration found that he had been living a twisted secret life.

The dentist is accused of not only hawking child porn and fixing a drug dealer’s teeth in exchange for methamphetamine, but he also allegedly tried to spread the HIV virus, according to the Brooklyn U.S. Attorney’s office.

Wolf told an informant he has the disease and “at times punctured holes in condoms” in order to infect his sexual partners, a court complaint said.

He implicated himself in wiretapped conversations between him and the informant, law enforcement sources said.

During their chats, Wolf also admitted that he had been reveling in sex parties with animals across Manhattan and Brooklyn, including a dog on one occasion, according to federal law enforcement sources.

In addition, Wolf “stated that he gets particularly ‘excited’ by specific child pornography videos and described a video depicting an 8-year-old ‘retarded’ girl engaged in sex,” the complaint alleges.

Wolf’s practice in Chelsea is located right next door to Nazareth Nursey Montessori, which holds pre-school and kindergarten classes for children ages 2 to 6.

During their investigation, Wolf gave an undercover FBI agent a flash drive containing sickening videos of children as young as toddlers being raped by men, the source said.

The kids in the clips ranged in age from 5 to 13, according to the complaint.

The investigation into Wolf and his debauchery initially began as a drug probe spearheaded by a DEA task force that also includes the NYPD and New York State Police, sources said.

When the authorities stumbled upon the child porn, they handed over the case to the FBI.

“Drug investigations have taken us down dark roads before, but nothing darker than the office practices of Dr. Wolf,” DEA Special Agent James Hunt said. “What began as a simple drug case quickly rerouted into an investigation into the alleged crimes.”

At his arraignment in Brooklyn federal court on Friday, Wolf appeared shell-shocked as he was held without bail by Judge Robert Levy.

“Given the overwhelming evidence in this case and the very disturbing facts, we don’t believe that there is any set of conditions that can reasonably assure the safety of the community,” said prosecutor Moira Penza.

When asked if he understood the grotesque charges against him, Wolf softly said “I think so.”

Outside the court, his lawyer argued that some of the sickening allegations should have been excluded from the court complaint.

“There are a lot things in this complaint that are not charged and are somewhat scandalous and embarrassing,” explained his lawyer, Marc Agnifilo, who is the former attorney for Dominique Strauss Kahn.

“It really shouldn’t be in the complaint,” he urged. “The government can’t help themselves. They get these startling details and they put them in the public record even though its not part of a charge.”

When asked about the assertion that Wolf is HIV positive — and that he deliberately tried to infect others — Agnifilo declined to comment.

“I can’t really can’t comment on people’s medical conditions,” he said, adding that Wolf’s world was ultimately shattered at 5 a.m.Friday when authorities showed up at his doorstep.

“He’s devastated,” Agnifilo said. “(He) woke up into a day where his life is going to be completely different. And these charges are not like other charges. These are charges that are hard to weather and I think he is understandably shaken.”

Prosecutors said that FBI agents found a flash drive containing 246 media files, most of which were child porn, as well as meth and drug paraphernalia during a search of Wolf’s apartment.

“The defendant admitted to possessing child pornography, denied having sex with minors, and indicated he was unwilling to discuss his drug use or distribution, or whether he had drugged anyone unwillingly during sex,” they explained.

A former patient of his said he was stunned by the revelations on Friday.

“It’s shocking,” said Robert Risko, who is a 59-year-old magazine illustrator.

“I went to him and had a root canal once,” he recalled. “He’s a funny guy, I’ve known him for years. A lot of people in the neighborhood go to him. But no, I’d never think this (could happen).”

When asked if he saw any red flags, Risko laughed and said, “Methamphetamine? Maybe.”

“You don’t know what secret lives people have,” he added. “But he was a jovial, happy fellow, he didn’t seem lecherous, but I don’t know if that makes any difference.”

Describing the environment at Wolf’s office, Risko said, “it’s like wacky, a little bit loose, fun environment…It was a little too fun, like a party environment…I used to say John is a little too fun to be working on my teeth.”

According to the court complaint, the informant told investigators that he had witnessed both Wolf and the staff at his office using drugs.

A worker at the practice who refused to give his name claimed he had no idea about Wolf’s wickedness.

“I never suspected this,” said the worker, who has been with the office for a year and a half.

“He’s an amazing guy, a very giving person. He helped a lot of people in the community,” said the worker, adding that Wolf is married with no kids.

Wolf faces charges of conspiracy to possess methamphetamine with intent to distribute, and possession and distribution of child porn.

A notice of his arrest was posted on Yelp asking anyone who may have been victimized to call the FBI.

Wolf attended dental school at New York University and has been in practice for 27 years, according to medical provider Web sites.