A filling did me the favour of falling out last week, a sharp reminder in the shape of food wedged between crevices that I had an overdue story about dentists to write. Strangely enough, it also made me reminisce, taking me back to the south of England and being a kiddy wink.

My first trip to see Mr. Foden the dentist who was setting up shop, my first spanking that really made me howl for buying cigarettes for my grandma when I was four, the first time I was rescued from a setting stuck up tree and how I used to tell my mum every Thursday I had fishy meat for “school dinners” (“What? Fishy meat? What do you mean?”).

So the filling that fell out was (kind of) the end of an era as well as a sign.

Some background. Two years ago, Tim Phillips decided to do an ultra marathon in the Atacama desert. Never done anything like, probably never would again, in his words, but it was a fund raiser. He asked me and Matt Chesterton to visit a slum-based dental project in the northern suburbs of Buenos Aires, San Martín, to check it was the real deal and that the organiser wasn’t bedecked in LV logos.

Run by Fiona Ambrosi, it was indeed the real deal and there wasn’t a sniff of Vuitton about her. Todos Juntos Foundation was making its mark with three dentist clinics set up within health centres despite the fact that one of Fiona’s main concerns was that so many children started yet never completed their treatment.

But we had the privilege of meeting siblings Joel Antonio and Ninfa Raquel, Paraguayans now living in Argentina, who were determined to get their disintegrated teeth back. Young teenagers, I assumed what would bother them most about having stubs for front teeth would be that they couldn’t have much luck with the opposite sex – but no, it was actually the excruciating pain of eating or drinking something slightly cold that they couldn’t wait to be rid of.

These weren’t vibrant or fun kids, they were quiet, shy, going through all the usual teenage angst but without a smile to try and give them some confidence. It was quite tragic.

A quick note on “why slumcat”. As we wandered, accompanied obviously, around the villa I came across a scrawny black-and-white kitten with the confidence of a lion. She followed us down the dirt tracks, tiny tail raised perkily high, and I asked some kids who she belonged to.

“No one,” they said. “It came out of the water.” What you and I call H20 was a lurid green, toxic pond filled with nappies, cars, plastic, rubbish, everything the slum dwellers no longer wanted. A section of this pond had even been filled in with sand and earth so that a house could be built on top of it. I assumed someone had tried to drown the skanky little critter, but she had remarkably survived it.

Anyway, the kitten, sturdy, robust and brave was adopted by Tim, whose son named her Pinguína, and while she revelled in our affection we all caught ringworm. Although Tim and family moved back to the UK, Pinguína was the slumcat millionaire who ended up living in Palermo Soho, and that was the headline for the Herald story I wrote.

Returning to San Martín some nine months later, I met Joel and Ninfa again who were in for a final check-up, and what a pleasure to see them. Chatty, happy, they couldn’t refrain from smiling. Wow. Determined to finish treatment, they had done it, and not only had Todos Juntos’ Project Sonrisa given them a great big grin, it had instilled a confidence and allowed their personalities to finally come through.