Diagnosis of occlusal caries

Diagnosis of occlusal caries
It might be expected that occlusal carious lesions would be fairly easy to diagnose,  because unlike approximal and subgingival root surfaces, these surfaces are readily accessible for visual inspection. However, clinically (visual or visual-tactile by probing) or radiographically, diagnosis of occlusal lesions is a delicate problem, because of the complicated three-dimensional shape of the occlusal surfaces, incorporating fossae and grooves with a great range of individual variations. 
Disease progression
It is a common clinical observation that caries on occlusal surfaces does not involve the entire fissure system with the same intensity but is a localized occurrence. Viewed in a stereomicroscope or SEM, the occlusal surface of a permanent molar appears as a convoluted landscape, with high mountains separated by valleys, some that are deep  rifts and others that resemble open river beds (Fig 201).
Each tooth type in the dentition has its own specific occlusal surface anatomy, and caries is usually detected in relation to the same specific anatomic configuration in identical tooth types. In maxillary molars, for example, the central and the distal fossae are sites that typically accumulate plaque and hence also the sites at which caries most often occurs. In general, occlusal caries is initiated at sites where bacterial accumulations are well protected against functional wear (see Figs 20 and 174). 
Thus, two factors have been considered of importance for plaque accumulation and caries initiation on occlusal surfaces: (1) stage of eruption or functional usage of teeth, and (2) tooth-specific anatomy. This explains why almost all molar occlusal caries is initiated during the extremely long eruption period (12 to 18 months) and why occlusal caries is uncommon in premolars, with an eruption time of only 1 to 2 months. This was confirmed in a 2.5-year longitudinal study by Mansson (1977), who examined first molars every 3 months from the start of eruption and found that
development of caries occurred, on average, within 11 months of the start of eruption, ie, during eruption (most had decayed within 3 to 9 months). On the other hand, there was virtually no further initiation of occlusal caries beginning 15 months after the start of eruption.
Monitoring for and measures to prevent the development of occlusal caries should be intensified during the eruption period (high-risk period). If the teeth have erupted into natural chewing function without developing occlusal caries, then the risk is over; examinations can be more cursory and less frequent. Nor is there any indication for application of fissure sealant.
In cross section, most molar fissures have a relatively wide opening (entrance) followed by a narrow cleft, approximately 1.0 mm deep and 0.1 mm wide, almost to the dentinoenamel junction (see Fig 116). The carious lesion usually starts in the enamel on either side of the entrance to the fissures and is visible as a noncavitated white-spot enamel lesion. Gentle probing with a sharp explorer will damage the surface zone of such a lesion and initiate cavitation to the lesion body. A rule of thumb is to use sharp eyes and a blunt probe (or no probe at all) and to arrest the
lesion by plaque control and fluoride. 
Most clinical and scientific concern with respect to occlusal caries has been over the possible events in deep and inaccessible fissures. However, caries always starts in the  surface enamel, from the metabolic activity of bacterial accumulations on the surface.
 It is reasonable to assume that evolution of plaque with cariogenic potential requires space that, in this context, is available only above the entrance to the narrow fissures, the grooves. This assumption is supported by ultrastructural studies indicating that, in contrast to the vital bacteria found at the entrance, nonvital bacteria or different stages of calculus formation are usually harbored by the depths of the fissures (Ekstrand,  1988; Theilade et al, 1976). 
Fewer than 10% of fissures are atypically flask shaped, with a narrow neck and a
bulbous base: The carious lesion can start at the entrance as well as at the base of the
fissure (see Fig 117). These fissures should be regarded as at risk. Fortunately, from a
diagnostic point of view, there is a strong correlation between steep cuspal inclination
and such sticky risk fissures.
Figure 202 shows an unusually wide, shallow fissure, full of stagnant, cariogenic
plaque and an associated noncavitated enamel lesion around the entire fissure. Figure
203 shows a so-called risk fissure with stagnant, cariogenic plaque in the entrance as
well as at the base of the fissure. In this case, localized, noncavitated enamel lesions
have developed on both sides of the entrance and around the bulbous base of the
fissure. However, even extreme risk fissures, with irregularities such as horizontal
tunnels, can be maintained free of caries (see Fig 118).
Progressive destruction of the occlusal surface thus begins as a local process in the
deepest part of the groove-fossa system, as a result of accumulation of bacterial
plaque. In this area, which is already sheltered from physical wear, the formation of a
microcavity further improves the potential for bacterial attachment and colonization.
This accelerates demineralization and destruction, further enhancing local conditions
for bacterial growth.
Figures 204a, 204b, and 204c show different stages of localized progressive occlusal
lesions in a mandibular molar with a discolored, cavitated lesion in the distal fossa.
The cross section of the lesion in the fossa shows superficial enamel breakdown with
cavitation into about 50% of the enamel but no cavitation into the dentin; ie, there is
no bacterial invasion of the dentinal tubules, and the lesion could be arrested (Fig
204b). However, the enamel lesion (demineralized area) is approaching the
dentinoenamel junction and there is demineralized dentin in the contact area,
corresponding to the direction of the rods. The anterior fissure in Fig 204a is shown in
cross section in Fig 204c. There is no progressive demineralization.
Figure 205a shows a localized cavity in the central fossa of a maxillary first molar.
The cross section of the lesion shows that the cavity is truncated and that the
superficial zone of destruction and the zone of dentinal demineralization are confined
to the involved enamel (Fig 205b). The cross section of the fissures shows that these
are filled with calcified material, indicating total absence of cariogenic plaque (Fig
205c). It is therefore assumed that the dark brown cavity is arrested or stagnant.
In people living in communities without dental health care, the natural progression of
occlusal caries is rapid, because of the particular anatomic configuration of the
occlusal surface where caries is initiated. Occlusal caries usually begins in a fossa, ie,
a depression where two or more interlobal grooves meet. Several surfaces are
involved in the initial dissolution, and the process is therefore three-dimensional.
Because enamel demineralization always follows the rods, the enamel lesion initiated
in a fossa gradually assumes the shape of a cone, with its base toward the
dentinoenamel junction. The response by the dentin corresponds to the direction of
the involved enamel rods. A section through such a lesion has the two-dimensional
appearance of two separate, independent lesions, but the lesion is three-dimensional
and actually cone shaped. Although textbooks have traditionally emphasized the
undermining character of occlusal or so-called hidden caries, the pattern of lesion
growth in these areas is not particularly surprising in the context of the structural
arrangement of rods in the occlusal groove-fossa system.
As enamel destruction proceeds, a true cavity forms, the outline reflecting the
arrangement of rods in the areas: The cavity has the shape of a truncated cone. The
particular anatomic configuration of the occlusal surface at the site of caries initiation
explains why the openings of occlusal cavities are always smaller than the base. The
“closed” nature of the process obviously favors undisturbed growth of bacteria and
hence accelerated destruction of the tissue. Occlusal enamel breakdown is the result
of further demineralization from an initially established focus, rather than general
demineralization involving the entire fissure system.
Figure 206 illustrates the progressive stages of lesion formation in an occlusal fossa,
from the earliest noncavitated enamel lesion to cavitation into the dentin with a zone
of bacterial invasion and dentin destruction, where excavation and restoration are
indicated. However, at the second-to-last stage (E), no such invasive intervention is
indicated, despite a considerable zone of demineralized dentin and a sclerotic and
translucent zone into the pulp. The method of choice would be placement of a fissure
sealant or a minimally invasive sealant restoration, using a resin-based glass-ionomer
material or compomer.
Views: 3063 | Comments: 9 Send reply
Hi Tiana, thanks for your cmmeont.Freelancing isn’t as easy as most people expect it to be, once you’ve established yourself in your area and have helped out a few dentists you’ll find things get a bit easier!The only advice I can give is to just put all your effort into selling yourself at the moment. As well as giving out leaflets, try giving out business cards so that practices can store your details easily. Physically go in to practices and introduce yourself when you’re giving out your cards! Give practices as much information as you can about how you’re going to work hourly rate,(remember you have to pay your own NI and tax) hours you are available to provide cover, whether you are available on short notice or prepared to cover maternity leave for example. Play on the fact that people are likely to be going away on holiday at this time of year and surgeries will need cover. Do whatever you can to sell yourself basically!!!I know how difficult it must seem at the moment, but I would stick at it and once you’ve worked for a few practices, ask them if they can write complimentary cmmeonts for you to use on your leaflets, just keep doing what you can to generate future work for yourself!!I hope my advise helps you.Katy

hi, your website is great.its silmpe but vey informative.i’m training right now to be a dental nurse and i’m about to take the exam. i hope you could write a coulmn about all the dental instruments used during dental procedures.thank you and keep it up!!!

Hi,Im qualified dnetal nurse with 11 years experience.Just moved house and trying out freelancing..I’ve sent out leaflets to various practices in my area but no luck just yet.Any advice on starting out and getting regular work?

Ouch, I was really sure you were going to come back and post about hanivg gotten your nerves in a bunch about nothing, I’m really shocked thats not the case and of course you’re going to be nervous about it. But the words and experience of the doctor sounds great and like you should be in good hands. Good thing its still early and you’re able to get good care in the US with time around your family and hopefully L to recover, maybe even master the subjunctive or something I’m confidant we’ll be back chatting over mediocre coffee and life’s sudden twists in no time. Hope you can relax a bit, I will be constantly sending good vibes of course http://sfelqcf.com [url=http://djcprpqfmsy.com]djcprpqfmsy[/url] [link=http://fwsqyitliey.com]fwsqyitliey[/link]

Terrible news, Ib4m really sorry. Strong or not, all of this will come to pass, and youb4ll have your faimly and L. beside you all the time.Also, it was better to find out about it in the U.S., with your faimly and a good doctor and medical services, than here in Chile. And, it was a good thing that you had this exam now, instead of ignoring your headaches and coming back to Chile without knowing what was going on.I think all this is terrible, but I have great hope that all procedures will work, and you will recover completely.

Ah man. That is definitely not the news we were all honipg for. I wish you the best through all of this. I can’t even imagine how you must be feeling. Stay positive and strong. You have a good surgeon on your side and family & friends to support you. We’ve got you in our thoughts too. Keep us posted on the situation, as you can of course.

That is so not a sinus infection. I’ll be kepeing you in my thoughts, and I believe that you can get this bugger out and still be you. Stay calm, and talk about whatever you want on here or wherever. It’s not your time to be strong if you don’t want to. I think this allows several freakouts, at least, if you are so inclined. http://xranvtu.com [url=http://lselvu.com]lselvu[/url] [link=http://uqtbzaib.com]uqtbzaib[/link]

suebob, srpaeate beds? srpaeate houses? The Mister also takes about 2 minutes to fall asleep. I wish i knew that trick.marsha, i’ll try that one, i sometimes sing long boring songs in my head.MOI, menopause does NOT help. No.u-u, i can go to sleep, but then i wake up about when you are getting to sleep and can’t go back to sleep. teri, glad you liked my silly joke. That one always cracks me up. In my family it’s standard to use the phrase On and On Anon when we run into a big talker.dick, if i lost the Mister i can’t really imagine getting to sleep after that. I have tried Benadryl, but that stuff makes me woozy all the next morning. Which makes me lose at squash. >:(bo, ha ha! That’s a good idea, and it wouldn’t wake up the snorers either. *Going off now to find a small notebook*kerianne, My Grandfather always used to say that to me. I haven’t heard it in years. thanks for the smile.josephine, exercise is a key for me too. I do something almost every day, maybe i should step it up a bit.antonia, yes, that’s a very accurate desciption. And knowing that i have to get up early makes it worse. I usually cover up the clock so i can’t obsess over the time.tracy, i’ll borrow one of the Mister’s programming books, that ought to do the trick.thailand girl, i listen to the BBC, but i’ll look for that program in this area.

I get what you’re saying, alguhoth my worries appear in the form of anxiety and the occasional panic attack. I worry about traveling, too. I worry about the magnitude of raising two children. I worry that Rex and I are so different… how do we get through 50 more years if we can’t get through the weekend without fighting over how to spend our money and time. I worry about not having enough money and time. I worry about my 76 year old mother. I worry about my makeup that I lost from leaving it on top of the car and wonder just how long I am going to look like a beaten down Irish washer woman before I plunk down 25.00 on Kmart replacements. Or should I spend the 100.00 on Mac makeup even if I can’t afford it? But if I did, I worry I’d leave it on top of the car and drive off again. And now I’m worrying about you worrying about me worrying about everything else. My point: I get it. You’ll be fine. Sign of an intelligent brain (though if we were so intelligent, why would this plague us? I worry about that, too.) http://xseqym.com [url=http://cowkpx.com]cowkpx[/url] [link=http://ndjijcvyo.com]ndjijcvyo[/link]

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Articles for theme “caries”:
Quantitative laser (light) fluorescence methodA method that is related to EFF and is attracting considerable interest is the quantitative laser fluorescence technique. At present, QLF can assess only accessible smooth surfaces and is limited to part of the enamel thickness.The principle for the QLF method is shown in Fig 199. The excitation is performed with blue-green light (488 nm) from an argon ion laser. The fluorescence in the enamel, occurring in the yellow region (approximately 540 nm), is observed through a yellow high-pass filter (520 nm) to exclude the tooth-scattered blue laser light.
Endoscopic filtered fluorescence methodPitts and Longbottom (1987) explored the use of EFF for the clinical diagnosis of carious lesions and compared results with conventional alternatives on occlusal and approximal sites. This work developed to include the use of an intraoral video system for caries detection, the prototype “videoscope.” Now that commercial intraoral cameras are increasingly available in practices, this may prove to be of practical clinical importance.
Alternating current impedance spectroscopy techniqueA more sophisticated approach to lesion detection and measurement is to characterize the electrical properties of the tooth and lesion by using the ACIST, which scans multiple frequencies. The ACIST is new and has been evaluated only to a limited extent on whole carious teeth. However, the results to date are extremely encouraging, indicating 100% sensitivity and specificity at the D1 level and only a marginal decrease in specificity at the D3 level (Longbottom et al, 1996).
Electrical conductance (fixed frequency) methodElectrical methods of caries diagnosis are not new. There has been recent revival of interest in fixed frequency electrical devices, which show considerable promise for detection of occlusal and approximal lesions. A device is now commercially available in The Netherlands; similar machines were produced in the United States and in Japan some years ago. The electrical detection methods are seen by many as having the greatest potential for significantly improving diagnostic performance in the years to come.
Fiber-optic transillumination methodFiber-optic transillumination is a development of a classic diagnostic aid, advocated some 20 years ago, which has never gained wide acceptance. However, it should be a regularly used tool for diagnosis of caries, in the incisor and premolar regions at least, to supplement clinical examination and bitewing radiographs. Fiber-optic transillumination has enjoyed variable success in studies evaluating its performance, possibly because of failure to appreciate that the technique, like any other, requires an extended learning phase.