It might be an issue with browser compatibility or site settings. Try clearing your browser cache or using a different browser. If that doesn’t work, there could be a problem with the website itself. You might also reach out to Premiere Dental directly for assistance.
Most likely you won't be able to zoom, so you'll only have to do that in safari. You can try to find the answer on reddit, but as far as I know, there is no answer.
Opera is bringing its Opera Touch browser to iOS to challenge Apple's default Safari browser, within a new lineup of phones such as the iPhone XS, iPhone XS Max and iPhone XR.