WHERE DO YOU START IN FINDING THE CULPRIT CAUSING THE POST-OPERATIVE SENSITIVITY FELT BY YOUR PATIENT AFTER YOUR TREATMENT?
We feel we have done it right. We have properly diagnosed the dental condition and problems of our patient and implemented the correct treatment, yet, a few hours later, the patient calls complaining about tooth sensitivity. Do we chuck it up as a normal occurrence that basically happens after treatment and will go away after a few days? Do we just advice for the patient to take pain medication and observe, and, if pain still exists days later to call you back? Does this happen to your patients so often that you already believed that post-operative pain is a natural automatic occurrence that our patients experience after restorative filling? Maybe...But, what if it is actually not associated with the inflammatory process that is indeed part of healing, and, probably caused by certain factors that we may not be aware of?
So, let’s discuss on this post the usual suspects other than the natural healing progression of the tooth from our treatment and our options to prevent them.
OVER ETCHING OF THE TOOTH
Etchant are made of 35% up to 37% phosphoric acid to prepare both the enamel and the dentin for the adhesive procedure necessary for our filling material such as composite resin to properly bond to our tooth. Etching of the enamel and dentin removes the smear layer and opens enamel and dentinal tubules to allow the bonding agent to freely flow in up to the level that is necessary for a successful adhesion. Why? Because basically composite resin, which is our general filling material used is hydrophobic. Thus, etching becomes a significant step. However, we, most often, take for granted the correct time as to how long this step should be placed on the specific tooth surface. Or, we become very inaccurate with the way we mindfully count the seconds of time, either too slow or too fast. Etching a young enamel will need at the most 60 seconds and for matured enamel not more than 20 seconds while dentin shouldn’t be more than 15 seconds. If we overdue or under do the time, this greatly affects the quality of bonding in our treatment. And, post-operative sensitivity do occur when we overdue the exposure time of our enamel and, more so, the dentin with our etchant. Relatively speaking, our dentinal tubules if over etched will look like a "overcooked pasta noodles" and will demineralized resulting to the inability of the bonding agent to penetrate into the etched surface of the dentinal tubules. In turn, this results to the inability of the resin component of our composite resin to fully bond on the tooth. A gap space is formed between the tooth surface and the filling material, so, when there’s force applied on the tooth during function, the pressure created by the force is not properly distributed between the tooth and restorative material causing tooth sensitivity. Etchant is also acid therefore, has a low PH that can result to pulpal irritation especially on deep cavities if not totally washed off.
SUGGESTED PREVENTIVE SOLUTIONS:
➢ Use a clock timer to time etch application and removal. Do not depend on counting the time in your head. It is always inaccurate.
➢ There are etchants in the market that are self-limiting. Best to use this kind of etchants because it automatically cease etching when it reaches a certain depth level of the tubules and prevents you from over etching either the enamel or the dentin especially if you like applying etchant at the enamel and dentin at the same time or you got distracted during the application and forgot the time.
➢ A thicker consistency of the etchant is also good to consider when buying one because you can really separately apply the etchant to the enamel first without dripping too much to the dentin until we are ready to etch the dentin next.
IMPROPER COOLING DURING TOOTH PREPARATION
Another cause of tooth sensitivity after tooth restoration is thermal injury. During tooth restoration, while removing the caries, a high-speed handpiece creates friction between the tooth structure and rotating bur. As the handpiece rotates, the bur rotates at the speeds of 200,000–400,000 rpm and can generate temperature that reaches up to 240°C. So, the improper cooling during tooth preparation especially at the dentin-enamel junction (DEJ) can do cause post-operative sensitivity due to heat damaged on the dentin and pulp.
SUGGESTED PREVENTIVE SOLUTIONS:
➢ Make sure that the speed your handpiece is running at the proper speed, so, you can cut and do your tooth preparation faster. The turbine is powered by compressed air, which passes up the central lumen of the instrument. The air pressure is usually 3 bar (43.5 psi), although, this varies depending on the handpiece manufacturer’s advice. Lower than that air pressure, means your handpiece is not generating enough power to do its job and may just cause heat and prolonged procedure.
➢As significant heat is generated during cutting due to friction, it is critical that effective cooling is provided over the whole cutting surface of the bur. Water is generally used to cool the bur. It is transported to the handpiece head via fine tubes within the body of the handpiece and exits via a number of small outlet holes, which are aligned to deliver the water onto the bur. Thus, the more small outlet holes available in the head of your handpiece, the better it is. Generally, a 3 small outlet holes will suffice.
➢ The main goal here is to make sure while doing your tooth preparation, it will not generate much heat to the tooth surfaces especially if it is a deep cavity, thus, you may use a low speed handpiece on the dentin surface on the areas closest to the pulp or a hand instrument to remove the carious decay instead of your highspeed handpiece.
➢ Cutting the time of tooth preparation will also help in not producing much irritation to the pulp that may cause post-operative sensitivity. Thus, besides, using the proper handpiece, the correct bur is also significant. Always remember its purpose. The carbide burs is for cutting and the diamond burs are for grinding. Make sure they are not dull or overused because this can also result of generating heat and exposure to this due to prolonged time of tooth preparation.
UNREMOVED HIGH PREMATURE CONTACTS
This is one of the most common cause of tooth sensitivity or pain after a dental restoration. The height of the restoration is higher than the natural tooth restored. This is due to excess composite or other restorative material that wasn’t properly removed. Thus, when force occurs during mastication or lateral excursion or other functions, the tooth will react to the pressure created by this which leads to your patient feeling the post-op pain or sensitivity.
SUGGESTED PREVENTIVE SOLUTIONS:
➢ Proper dental history taking which includes bad oral habits of the patients must be taken and used into consideration when we decide the type of treatment we will implement.
➢ Always check the vertical dimension, canine guidance, overjet and overbite of the patient before and after the dental treatment.
➢ Remove all the premature contacts and take time on the finishing and polishing procedure which is often done in a rush by many dentists. These steps are actually one of the critical steps to have a truly successful restoration.
FRACTURE, CRACK, OR MICROLEAKAGE IN THE RESTORATION
Under filling, improper curing, using expired or substandard restorative material, over polishing or improper diagnosis and treatment, to name a few, may result to fracture, crack, microleakage between the tooth surface and the restorative filling material. Thus, contamination of the restoration or application of untoward force during function may change the condition of the tooth brought about by temperature change or undue pressure to the said tooth which in the end results to post-operative pain.
SUGGESTED PREVENTIVE SOLUTIONS:
➢ Always buy critical equipment and restorative materials based on quality not on price. For example, there’s a reason why some LED lights are more expensive than the others and why we need to listen on the features and benefits of the products before we buy.
➢ Always follow protocols in the procedures that we do and use the materials and equipment according to the manufacturer’s instructions.
➢ When crack or fracture is a suspect culprit and it not immediately visible to the naked eye, use transillumination. Transillumination is the detection method that provides the most information if you feel x-ray is not necessary, such as the green light that can detect cracks. If this equipment is not available, a simple tooth sleuth can suffice to check presence of crack or fracture either on the tooth or filling or both.
➢ Additional restorative material such as resin-content only can be additionally applied to the junction of the tooth and the restorative filling material after finishing and polishing to reduce chances of microleakage in the cavosurface margins.
PULPITIS
The possibility of the presence of this condition in deep seated caries when restored is higher than in cavities that are not that deep. We all know that we can inadvertently cut the dentin too close to the pulp and even may unknowingly exposed the pulpal horn. Thus, pulpal exposure as the culprit for the pain our patient is feeling after our restorative treatment is not an impossibility.
SUGGESTED PREVENTIVE SOLUTIONS:
➢ In cases of deep cavity, it is always best to take a before and after periapical x-ray for proper diagnosis and treatment assessment.
➢ Depending on the type of restorative filling material used, a calcium hydroxide base either resin or cement is always ideal to provide an anti-bacterial protection as well as added layer of protection to the pulp for deep seated cavities.
➢ Always explore and check the pulpal floor if the pulp is not inadvertently exposed while removing the caries before starting to restore the cavity.
➢ Make sure when using high-intensity LED lights not to put too close to the cavity when curing our restoration. There must be at least 1-2 mm distance from it.
CONCLUSION
As you can read from our suggested preventive solutions, the techniques and methods are not difficult to do and very practical. In fact, the solutions are more on how we should do things and being strict not skipping certain steps in the procedures that we may deem unnecessary or not that important. Ironically, preventing our patients not to feel post-operative tooth sensitivity after our treatment other than the tooth’s natural healing process is by just doing all the necessary protocols we’ve learned from school. After all, they are included on those protocols even if they seem inane and insignificant for a reason. Problems whether in dental or in life are generally solved through simple and straightforward solutions.
CONTRIBUTORS:
Dr. Bryan Anduiza - Writer
Dr. Mary Jean Villanueva - Editor | Writer
