Tufts University School of Dental Medicine · United States Army · American College of Prosthodontists
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Dr. Miles R. Cone is a graduate of Tufts University School of Dental Medicine, and completed a three-year Prosthodontic residency program while serving in the United States Army before being honorably discharged as a field grade officer in the rank of Major. Miles is one of only two prosthodontists in the entirety of New England to have obtained additional qualifications as a Certified Dental Technician. He owns a private practice at Nuance and is Editor in Chief for the Messenger, a quarterly publication by the American College of Prosthodontists.
Should you make the leap to electric handpieces, or could the latest air-driven technology deliver the power you need while maintaining the ergonomic advantages you prefer?
Dr. Miles R. Cone brings a unique perspective to this handpiece debate. A graduate of Tufts University School of Dental Medicine, he completed a three-year prosthodontic residency while serving as a Major in the United States Army. As one of only two prosthodontists in New England with additional qualifications as a Certified Dental Technician, Dr. Cone combines clinical expertise with technical precision. He owns Nuance Dental Specialists in Maine and serves as Editor in Chief for the Messenger, the American College of Prosthodontists' quarterly publication.
This conversation explores the evolution of handpiece technology and challenges conventional wisdom about electric versus air-driven systems. Dr. Cone shares his journey from exclusively air-driven to electric during the pandemic, then back to advanced air-driven handpieces that rival electric performance. The discussion covers real-world clinical scenarios, from removing multiple zirconia crowns to creating precise margin preparation, offering practical insights for prosthodontic and restorative workflows.
Episode Highlights:
Advanced air-driven handpieces now generate 44 watts of power, enabling rapid removal of full-coverage zirconia crowns in minutes rather than the extended timeframes previously required. The quick-stop functionality provides immediate cessation when the rheostat is released, enhancing patient safety during crown removal procedures.
Hybrid handpiece systems allow prosthodontists to leverage air-driven units for bulk tooth structure removal and tight access areas, while switching to electric handpieces for refined margin preparation and final finishing work. This approach optimizes both efficiency and precision in comprehensive restorative cases.
The 100-degree angled head design on newer air-driven handpieces significantly improves visibility and access in posterior regions, particularly beneficial for second molar preparations where space constraints and patient anatomy create challenging working conditions.
Equipment longevity and reliability prove critical for practice productivity, with some micromotor units maintaining consistent performance after 11-12 years of daily laboratory use. Customer service responsiveness and repair turnaround times become essential factors when selecting handpiece manufacturers for practice investment.
Cost considerations favor upgrading to advanced air-driven handpieces over complete operatory retrofitting to electric systems, particularly for new associates or practice transitions. The performance gap between high-end air-driven and electric handpieces has narrowed substantially, making air-driven a viable alternative without infrastructure changes.
Perfect for: Prosthodontists, restorative dentists, and general practitioners evaluating handpiece technology upgrades, particularly those working with zirconia restorations and complex crown removal procedures.
Discover how the latest air-driven technology might revolutionize your clinical efficiency without the investment required for electric conversion.
Transcript
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This transcript was automatically generated and may contain errors or inaccuracies. It is provided for reference and accessibility purposes and may not represent the exact words spoken.
You know I can tell you how how comparable it is to the electric hand pieces and you won't know
until you cut off that first second mandibular molar that's got a full coverage zirconia crown
that's when you will really appreciate that handpiece and what kind of power output it has eight
years ago when we first did our first podcast i would i could not have imagined having this
conversation with you now that i could cut through you know half a dozen zirconia crowns and in as
many minutes you know it's as fast as i can like you know hold the rheostat down i can get through
these these crowns welcome to the Phil Klein Dental Podcast as electric hand pieces gain popularity
for their torque and cutting efficiency many of us feel pressured to make the switch however before
making that decision it's important to explore the latest advancements that have taken air-driven
hand pieces to a whole new level in fact according to our guest One air-driven handpiece in
particular stands out above the rest for its ability to cut through zirconia with ease, making it
the primary workhorse in his busy prosthodontic practice. So before you make the leap to electric,
do your homework. Understand the latest innovations in air-driven handpieces and how they compare
in terms of power, longevity, and ergonomics. The right handpiece isn't just about the latest
trend. It's about what fits your hand, your technique. and your patient care philosophy.
To tell us all about it is our guest, Dr. Miles Cone. He's a graduate of Tufts Dental School. He
completed a three-year prosthodontic residency program while serving in the United States Army.
He's also a certified dental technician. Dr. Coneand his wife own and operate a private practice
prosthodontics clinic, Nuance Dental Specialists, located in Yarmouth,
Maine. Dr. Cone, it's a pleasure to have you on the show. Phil, it is always a pleasure to be on
the show. We're always happy to have you on the show. Dr. Cone, you've contributed quite a bit to
Viva Learning. And our first podcast together was seven years ago, hard to believe 2018. So the
show is still cranking along. Our audience is growing. And I want to thank our audience for that
because without our audience, there's no show. We all know that. That's how it works in media. So
this topic is interesting because it's something that... and dental professionals of all roles talk
about? Electric or air-driven? And that's a question that's commonly asked at the dental
conventions and so forth. So where are we in the trend right now? Where are we in the operatory
regarding the prevalence of electric and air-driven handpieces? Which one's winning the battle
here and why? So that's interesting. So coming out of dental school, we used exclusively air
-driven. And I know that my former assistant, who's now also a first-year dental student,
she's using air-driven. And I had never heard of electric until I went to my first trade show. I
think it was the Yankee dental show in Boston. And I saw these handpieces and they were electric.
And I thought, what's an electric handpiece? And what's the value? What's the benefit? And of
course, the first thing they tell you is, oh, the torque. It's got so much power. And then, of
course, they've got a... of zirconia there and they say watch this doc and then they come through
it and you're amazed that it cuts through this one inch block of zirconia and you know 10 seconds
and you think well i must have that right i need to have that thing right and then you go back to
your um your pre-clin days and seeing your patients at the dental school and you don't really hear
anything about it for a while and then you get into residency and now well at least my residency
was in the military so we had everything it was all free well your taxpayer dollars you and the
listeners taxpayer dollars so we had all of these different options you know for things to try And
the prosthodontists anyway, I don't know, maybe we got, maybe we were at the low end of that totem
pole. We just, we didn't have all of the cool features. I know the endodontists, they were all
using electric, the periodontists, they were all using electric. And we tended to stay,
even though we tried them out, you know, the mentors had us try them out. We all tended to stay
with the air driven hand pieces. And I, I think the reason was that. At least for me,
I can't speak for my classmates, but at least I liked the tactile feel of it. It was smaller. It
was streamlined. I enjoyed the air driven. And it was also what I knew, you know, we were just
overwhelmed and inundated with information and new stuff. And so I didn't want to switch, you know,
if it wasn't broken, why fix it? So I think I stayed with what I knew from my dental school days.
So for your entire career, even up till now, you're using air driven hand pieces. You do use some
electric and we'll get into that. But something happened. during covid where you decided to try an
nsk electric handpiece tell us what happened there and so during the pandemic um we had a lot of
down time and i thought you know what i'm gonna i'm gonna make the switch and nsk had um these air
sorry these electric hand pieces that were really there was a really really cool feature where you
could switch from like an aerosol and you could kind of turn it off and you could dial it down from
like a water stream to like you know and it was this really um tremendous kind of step forward in
terms of hygiene because we didn't want to be breathing in bad bacteria nobody knew what was going
on and so i moved almost exclusively to using electric during that period and i kind of fell in
love with electric you know all of the things that you hear turns out they were true was that a big
transition for you because the setup for electric is is far different than a air driven yeah it was
it was definitely there was uh some you know financial investment made Not just for the hand
pieces, but also for the tubing and the connections at the chair. You know, you needed a different
computer system there to integrate with that. But there was a lot of things about the electric that
were really great. And again, as a prosthodontist, my big thing was how much time am I spending
removing old dentistry? And you know, you know, you've done podcasts with other folks,
you know, zirconia is huge. Zirconia is like everywhere. Everybody's placing zirconia. Why?
Because you can mill it out in office. It's easy. It's fast. Generally looks pretty good. But then
we get these, you know, people that were doing teeth in an hour, you know, not to knock on that.
But I mean, they were doing a lot of very fast dentistry that wasn't the cleanest, you know, and
then patients were getting recurrent decay on the margins. So now I'm confronted on a Monday
morning with a patient that has six to eight full contour zirconia crowns that I have to remove.
There's no way you could do that with an air driven, you know. said miles cone i'd have arthritis
in my hand by the time i was done you know it was just awful it was it was not a fun day those were
not days that we looked forward to you know the patients didn't like it because they're sitting
there in the chair you know the teeth are getting hot there's water everywhere it just takes
forever and so the the electric would just mow through these teeth you know as fast as i could hold
down the the rheostat you know it wouldn't lose any of the torque and it would just zip right
through the it was great The one downside, you know, people always ask, and I like to be authentic.
They want to know what the downside is. And the thing about the electric that I don't like that I
know that I don't know if I'll ever get used to is they're a little bit bigger. They are a little
bit bigger. And for a lot of clinicians, I know that doesn't bother them. That doesn't matter. Most
of the dental offices that you're asking about trends, a lot of the dental offices that I go to
when I'm assisting in surgeries, when I'm assisting my endodontist. They're all using electric.
They love their electrics. They swear by them. And actually, I think they saw one of my interviews
or videos and they went out and bought all the NSK. They outfitted their entire clinic with NSK
hand pieces. And now when I go there and I have to like do a crown prep at the chair,
you know, they're putting like a post in or they're taking a tooth out and I got to like adjust it.
I bring along my air-driven hand pieces, you know, if I just need that just delicate little
balance and I don't need that kind of torque. But then, you know, and I had talked about this for
years with my wife, you know, these are the conversations that you have at like three. in the
morning when you kind of wake up and you're like, oh, wouldn't it be so great if, you know, things
that you write down on a napkin and then you always wonder if, you know, the folks in the ether are
listening to your conversations. Because I think right around the time of the last IDS, my wife and
I were there, we were, you know, speaking for a few companies and there were these massive NSK
banners like hanging. And I remember I called the folks there, you know, I hadn't been made privy
to the new hand pieces that were in the works. And I called, I remember I called up the folks.
that we know here in North America. And I said, are you guys coming out with a new handpiece that I
don't know about? And they said, oh yeah, we've got these new air-driven handpieces. And NSK was
making a big push towards electric. And I said, well, you have air-driven. What's new about the
new? And they said, well, until you use it, it's hard to explain and just see just how much it is.
You won't believe until you use it. But the torque is, it's insane. It's incredible. The power and
the output, it's going to rival electric. And I thought, No way. Yeah, I can't blame you for being
skeptical, but that's the Timex Z series, correct? Yes, yes. So it's their titanium,
it's these Timex Z series, and they are absolutely phenomenal.
And again, and I'm going to say, I'm going to echo the same thing that they told me until I can say
it, you know, I can tell you how comparable it is to the electric handpieces, and you won't know
until you cut off that first, second. mandibular molar that's got a full coverage zirconia crown
that's when you will really appreciate that handpiece and what kind of power output it has and that
was the first time when i thought you know what these are the real deal nsk sent me um on loan they
sent me each one of each it was like um i believe it was a micro which you know i don't use a lot
of micros it's more for like pediatric dentists um there was the timex z 890l and then they have
the like their larger kind of their workhorse um the timex z 990l but i'll tell you you know and
i've mentioned this to people before even though i don't do pediatrics that little micro it is
quite powerful and it can get back in those little nooks and crannies But on my patients that have,
you know, don't have microstomia or, you know, trismus or something like that can actually open.
I'll tell you what, man, that T, the Timex, yeah, Z990L,
like that is my go-to now. And, you know, I don't want to say that my electrics are collecting
dust, but this one, this handpiece is, if I could afford it,
I'd have a dozen of them. For the equivalent power that it produces versus an electric. it's
substantially smaller you notice the size when you practice and that's yeah and that's the key
factor and benefit that you like is that it's smaller and lighter to me yeah i i notice it it's
definitely a little bit smaller i've heard this from other folks they said you know how it feels
like the electric feel like a little bit larger and they are a little bit larger and even though
they've come down they are pretty streamlined they're pretty small um the air drivens are always
going to be you know have a have a smaller like footprint i guess in your hand or in the mouth so
to speak and you know one of the things i think that i noticed first about this i told you like you
know we get these patients coming in they've got these old this old dentistry and it's always on a
second molar it's always on a patient that's gagging and can barely open and these have they have
like a hundred degree angled head and so that angle just really lets you see back there my wife
calls it no man's land because i'm just kind of prepping blind back there And for once, I actually
have a little bit of visibility. And for once, I actually have that power, you know, in the back
where the handpiece isn't slowing down. And I can get through these crowns really fast. And
because, you know, as a prosthodontist, I mean, I'm just prepping teeth all day. Yeah, let me ask
you about that. So you are a prosthodontist. And tell us from the perspective of your margins,
putting that chamfer on, when you have an electric, isn't the argument that there's a continuous
torque and continuous steady speed? power coming through that handpiece where you can create this
very precise finish line of your prep versus air driven where you're you know you got your foot on
the pedal and you're pushing air through is there anything to be said for that or what's your
what's your thought on that yeah that's a very good question phil so i will i will say this with my
electric hand pieces i can get a very very clean margin because of that continuous um you know
speed that it's you know i'm not like it's not stop and go stop and go stop and go and so for those
types of things i still go to my electric and you know People that have, I always get students that
want to come by and shadow at my office and they always point to, they're like, oh, what's up with
this handpiece? And that one's got a red line on it. What does that red line mean? You know, I was
like, well, this red line, that's my electric. These ones, these are my air driven. And it's on the
same unit, you know, and they always ask, well, why do you have sort of a hybrid system? And I say,
because, you know, if I have to prep teeth for like. long, you know, I want something that's
lightweight, otherwise it gets kind of heavy over time. But the electric, when I need to refine my
margins, I will still go back to the electric, you know, and I'll make my margins nice and clean,
especially if it's, you know, you've seen my work, I'm showcasing these, these crown preps and
magazines and photos, and I want it to look just like exquisite, you know, not to say that I can't
get that with my air driven, because I certainly can. But it's nice to have the option of using the
air driven. Like when I need it, you know, so there's there's a lot of reasons to have to have
both. But this for the folks that are concerned about going air driven because they've been using
electric, they've gotten used to that, that power that they're generating. I would highly recommend
trying these air driven hand pieces. I do not think you'll be disappointed. So I guess one thing to
consider is, Dr. Cohen, that if a dentist is an associate at a dental practice and then he takes it
over. for instance, instead of retrofitting the entire practice with electric,
because they've been advised of the power, torque, and speed that electric provides, it's a lot
less expensive to just advance the actual handpiece and keep the system the way it is to save those
costs. Does that make sense? Yeah, 100%. Before you start retrofitting things and incurring that
extra cost, especially if it's a new associate or employee, you're going to have so many bills and
things like that. I would suggest 100% Try these air-driven hand pieces.
You know, try, you know, again, if you're doing pedo, sure, get the micro.
But my recommendation would be to do the Z990L. That is going to be... So close in comparison to
what you're used to with the electric. It will not disappoint. And I will put my license on that
and guarantee it. It is a very, very powerful handpiece. It has 44 watts of power that's being
generated. And the cutting is just, it's so exceptional. It's so fast. And the first few times that
I used it, I was like, oh, you know, should we have... And we did that. We went through that
process of retrofitting during the pandemic. So again, I know the pain points of the costs
involved. You know, I thought, huh, maybe I should have just, maybe I should have tried this first.
I was a few years too late. But you know, we're in a great time in dentistry now where we have
these options available. So let's talk about something else that's very important. And that's the
company that actually manufactures the equipment. You're a prosthodontist. Your livelihood is based
on your equipment performing reliably every day. We can't just judge the equipment by how it
performs the day we buy it. We want to make sure we get something that's going to last a long time.
And you have a story that I found very interesting relating to a micro motor that you bought many
years ago. And this stemmed from your residency program. A lot of the residents would set up their
own little at-home mini labs because you were just away from family forever. So I went on eBay.
and i bought an nsk micromotor it's a z500 so anybody that's listening you won't find this anymore
they don't sell this one they have a they have a new one like a new and improved one i bought this
11 12 years ago second hand this thing and i use it every day I mean,
trimming my provisionals, grinding on my dentures. It's my laboratory micromotor.
This thing is like my Toyota 4Runner. It's never going to die. This thing has a million miles on
it. It will not die. And when I was speaking to the folks at NSK,
they were like, you know, Miles, we can send you one of our new ones. I was like, you're going to
send me a new one. It's going to be in a box. Like this one works. Yeah. So it's important when you
make a decision to outfit an office, when you're putting the equipment in, when you're planning,
you really want to, make sure that the company that you're getting this equipment from is has a
track record number one and also stands by their product on warranties and what's the warranty on
do you know the warranty i know that's kind of a specific question that might be um i don't know to
be honest with you i'm not certain um i know all i know is that like the hand pieces i had before i
switched over to nsk whenever i'd send them in you know we'd get like a 75 repair bill for the the
ball bearings or whatever it was but the thing and i don't even have an issue with like whatever
the cost to repair it is because you get what you pay for i mean it's a good high quality product
and you can tell from the moment that you feel it what's important to me is that i have customer
service right and the folks at nsk are awesome you know and i always joke that even if they even if
they fired me like i would still have like use exclusively their products they're so they're so
easy to get in touch with and that's really important too is that you have like a contact that you
have a connection and i know like some dentists want to like you know find off-label stuff and off
-market like stuff but i'm like just don't just go go with the the good quality hand pieces from
the beginning especially a hand piece i mean there's other areas where you can cut corners Like you
could cut corners on your two by twos and your patient bibs. So no doubt we all rely on our
equipment every day. And when a piece of equipment goes down, it certainly can hurt workflow and
productivity. But all equipment in reality has a serviceable life. And once we get to the end of
that life, we want to replace it. What are some of the signs of a handpiece that's on its way out?
And the reason why I'm asking this is because we should take notice of these. symptoms, so to
speak, so we could replace it or repair it promptly so we don't have any downtime. So in my
experience, you know, from the past, I've noticed that I'll hear noises inside the hand,
like wheezing and whirring that was never there before, you know, and that could also be a product
of me just not cleaning it. But I'm very I'm pretty diligent about, you know, cleaning and spraying
and lubing my hand pieces. You'll note I'll notice sometimes my other hand pieces, you know.
like residue coming out you know the back end or or the head you know different things like that
the it'll slow down it's not cutting as fast or it'll it'll it'll start to cut and then it'll just
stop it'll be kind of stop and go and you sit there and you try to you try to figure it out and you
tinker and then and then at some point like i said you just eventually just want something that
works yeah and the time that we spend chair side is so valuable as dentists you can't yeah there's
no excuse for using anything that you're frustrated with that takes up time and slows you down and
just takes the joy out of practicing. So at this stage of the game where we are now,
and I know you're a big fan of NSK, but there are other handpiece companies out there that make air
driven and electric. Are we at a stage right now in dentistry where most of the top brands should
be pretty reliable? You know, this is the thing, I guess, as a KOL, and I don't like the term
influencer or whatever it is, but I get DMs, I get messages, I get hands raised in the audience all
the time. Well, hey, I've got like this, you know, whether I'm showing like the scanner I use,
whether I'm showing the impression material, whatever the product is, the ceramic. Yeah, but I use
and then insert whatever the competing company is, right? And I always say,
you know, it's kind of like wizards and wands, like a really good wizard can, you know, create the
spell it's not the the wand that they're using but let me say this with a caveat i have used a lot
of hand pieces and i do think that there are marked differences and again maybe because i'm a
prosthodontist i'm very acutely aware of those differences you know like the the folks who are like
the the high-end car aficionados or the high-end watch they notice like the differences in those
things which is why they like to spend the money on those those nicer things i do think there's a
lot of good hand pieces out there i mean i know what i'm going to use until i retire you know and i
can't speak for other companies because for the last seven eight years i've been i guess faithful
and monogamous to one to one company you know but i but you've tried but you've tried several other
major brands you have tested them and i know they have a trial program with nsk you can actually
try the handpiece which seems quite generous uh for something oh yeah no no no so in the beginning
yeah they do have a trial program and nsk sent me a bunch of handpieces they're like hey try these
out you know return them when you're done you know And I never returned them. I was like, no,
they're good. And then came the invoice for the next six that I had to purchase. They're really,
really great hand pieces. And again, I don't want to sound like just like an NSK fanboy, but I
mean, there are certain products that when you tell people that you use them, you don't have to
explain. well, why did you get that? Or why are you using that? And I feel like NSK is one of
those. So for the listeners that are out there, Dr. Cone, that are considering purchasing a new
air-driven handpiece in the near future, what are the key features and benefits that should be top
of mind for those dentists who are in that position? Yeah. So again, you know, being an extension
of... as a clinician, obviously, I want something that's ergonomic. And, you know, you and I have
chatted in the past about our pain points, like, you know, all puns intended about being a tall,
lanky dentist. You know, I need I have so many other pain points. I don't need that in my wrist and
hands as well. So I want something that's lightweight. It's got a nice tactile feel to it. You
know, I also want something safety because there's a human being attached to these white things.
Right. I need a handpiece that's got. a high level of safety these air-driven hand pieces the
timex hand pieces new nsk hand pieces they have a feature on them this quick stop functionality i
don't know if that's the technical term that's what i call it's a quick stop feature that when you
stop him within a second it just it stops it doesn't like it doesn't like gradually like taper off
you know it's like it stops like so when i start it starts when i stop it stops that's really
important um again having great customer service i think that one goes unsaid a lot of times people
just want you know you hear people say i want it to be less expensive i want to be no man i want
somebody there for me like when and it'll be a when it's not an if like when you need a repair when
something goes wrong i want that company to be johnny on the spot i want a replacement i want it
fixed i want it You know, I want them I want to know, like, I want to feel like they're a partner
in this process with me and not just there to make money. You know what I mean?
So other things. Yeah. You know, the torque is always going to be the big one. And that's what you
hear people talk about. Oh, the torque, the torque. You know, how much power is this going to
generate? And so and I think that's the thing for any anybody listening. Like, again,
we've said this enough times, but. these hand pieces have so much just power generated from them
that was not previously available like when we started our practice eight years ago when we first
did our first podcast i would i could not have imagined having this conversation with you now about
how in love with air driven i was specifically for the reason that i could cut through you know
half a dozen zirconia crowns in in as many minutes you know i mean it's as fast as i can like you
know hold the rheostat down i can get through these these crowns that's what's beautiful about the
free market you know electric was gaining some momentum among the clinicians because of what you
said primarily the torque that's all we heard about and we saw the trade shows and the videos of of
this thing cutting through zirconia like butter and people like they're air driven though so the
manufacturers upped the ante with the air driven hand pieces and now it rivals electric You know,
you could do fine with an air driven without having electric, although to have the best of both
worlds isn't a bad thing. But that's that's a luxury. Right. Right. And again, if somebody said,
hey, unlimited budget, what would you do? I'd tell them both. Just like what I mean, I'm biased
because I have both, you know, and I recognize the benefits of those. If I have a full mouth rehab
to do, you know, and it's a it's a lot of old crowns to cut through, you know, maybe maybe I'll
grab. the electric after all, you know, and to start going to town. But if it's, you know,
like I said, if it's like half a dozen teeth, like a six through 11, we get that all the time. They
had some veneers placed somewhere else that they don't like and it's bonded on. And I, and I, or if
I'm working in a really tight space again, any, any crown that I have to cut off or prep,
you know, if it's like a natural tooth, it's a first or second molar. I'm almost always going to go
to my, my air now, my, my nine 90 L if it'll fit because.
It's just smaller and I have that space and I have that visibility. And that was something that
I've missed for the last few years that I have that luxury and that convenience now. Yeah. No,
fantastic stuff. Congratulations, Dr. Cone, on your new practice, relocating your new practice.
It's really exciting. We're certainly going to have you on more podcasts coming up to follow how
you've digitized your world through the recommendation of your wife, which is fantastic.
Oh, yeah, you know about that. Oh, yeah, I know about that. Thank you. Yeah, I mean, just so you
know, folks, Dr. Cone’s wife went to a dental convention meeting. Dr. Cone was lecturing and his
wife was out there talking in the hallway to all these dentists that were completely digitized. And
when he came off the stage later on, she said, Miles, we need to digitize our practice.
And he was the one that was lecturing. And sure enough, they did. And we did a series of three
podcasts on your digital workflow, which was really fantastic. That's right, yeah. And now that's a
huge part of my... My content now is digital dentistry and, you know, showing workflows for that
now. Yeah, we got to thank your wife for that. Crazy how things have changed. Absolutely. All
right. Well, good luck to you. We'll talk to you soon, Dr. Cone. Thanks so much for a very, very
good podcast. Thank you. Always. Cheers.
Clinical Keywords
Miles Coneprosthodonticshandpiece technologyair-driven handpieceselectric handpiecesNSK Timex Z serieszirconia crown removaldental equipmenthandpiece torquecrown preparationmargin preparationdental technologyprosthodontic workflowhandpiece ergonomicsdental practice managementPhil Kleindental podcastdental educationhandpiece comparisondental equipment reliabilityclinical efficiencyrestorative dentistrydental prosthetics