As is well known, correcting teeth can improve appearance, but wearing braces also increases the difficulty of oral hygiene.
Many people who wear braces will go to the bathroom to brush their teeth and rinse their mouth as soon as they finish eating.
Why is it more important to clean our teeth properly during orthodontic treatment?
This is because there are easily food residues, soft dirt, and plaque residues on the brackets and archwires, and there are more "corners" that need to be cleaned, which increases the difficulty of brushing teeth.
It's not a big problem if the teeth are not cleaned once in a while, but if they are not cleaned properly for a long time, the teeth will develop caries.
Image 1. PNG
As shown in the figure, the brackets and archwires on each tooth are the most prone areas for bacterial colonies to accumulate, which is often the most overlooked part of our daily cleaning.
How to prevent dental caries?
There are seven main ways to prevent dental caries during orthodontic treatment:
Brushing teeth, flossers, interdental brushes, flossers, regular fluoride application, pre orthodontic treatment for existing dental caries, and good dietary habits.
Let's learn together today:
How to clean teeth during orthodontic treatment?
During the correction period, brush your teeth with toothpaste and toothbrush. In addition to brushing your teeth after waking up early and before going to bed, you should also brush your teeth after three meals.
In addition, the dentist suggests that after eating snacks, it is also best to brush your teeth.
Toothbrush selection:
Try to choose toothbrushes with small heads and soft bristles, or use orthodontic specific toothbrushes to fit our teeth and brackets, and better clean the tooth surface.
Toothpaste selection:
Choose fluoride toothpaste for brushing teeth.
Brushing method:
Use the horizontal vibration brush method for teeth cleaning.
Interdental brush:
The interdental brush can effectively clean the tooth surface under the archwire and between the brackets, keeping the oral cavity clean.
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oral irrigator
A dental irrigator can effectively assist in cleaning teeth.
When working or gathering outdoors, a dental irrigator is more convenient for cleaning the mouth, but it cannot replace brushing teeth!
Regularly apply fluoride
In addition to daily oral hygiene, we also recommend that everyone regularly visit professional institutions and have dental specialists apply fluoride to protect our teeth.
It should be noted that if dental caries have already been treated before orthodontic treatment, we should first cure the caries.
Because treating dental caries after starting orthodontic treatment, wire braces can hinder the doctor's operation and require the wire to be removed before treatment, increasing the difficulty of treatment;
Another reason is that teeth are not properly brushed during orthodontic treatment, which can easily lead to tooth decay. If dental caries are not treated before starting orthodontic treatment, they may develop faster and be treated later when they become more severe. Orthodontic treatment may also need to be suspended.
eating habits:
Good eating habits are also important preventive measures for maintaining oral health.

Eat less sweet food
Eat less sweet foods, especially stay away from free sugars such as fruit juice, sucrose, fructose, and syrup in food additives; Instead of free sugars, such as natural sugars in fruits, they pose little harm to our teeth and can be consumed in moderation.
Eat more coarse grains

Author: Zhang Zhen
Huazhong University of Science and Technology Tongji Medical College Affiliated Union Hospital Stomatological Center

We know that the first incision in conventional single implant surgery is crucial, and once the incision is made, it becomes difficult to make further changes. One size fits all, with less intraoperative bleeding, less blood stained surgical instruments, clear surgical field of view, minimal tissue trauma and neat edges, easy suturing after surgery, and mild postoperative reactions in patients. If not handled properly, it will not only affect subsequent surgical procedures, but also lead to severe postoperative reactions in patients.
In my clinical teaching process, I often found that students tend to have some doubts when making surgical incisions in the first step of implant surgery. For example, why can't the incision flap be opened? Why does flipping the valve block the implant preparation hole? When can I use a ring cutter instead of making an alveolar ridge incision? What risk factors need to be considered before the implant is about to be implanted into the alveolar bone?
In response to the common problems among beginners mentioned above, the following are my insights and opinions, hoping to benefit all dentists.
01
Flipped: Think about this' hamburger 'structure
The following figure shows the area that needs to be exposed by flipping the flap (Figure 1). In this planting area, the mucosa has a three-layer structure, and this is where we want to flip the flap. For the convenience of memory, you can refer to my original "hamburger model" (Figure 2): the top layer of bread represents the epithelial layer, the bottom layer of bread represents the periosteum, and the middle layer contains various tissue structures, such as blood vessels, nerves, fat, connective tissue, etc., which are complex and intricate. We call it the "sandwich layer" for short. However, remember that this burger is a mini burger with an average thickness of only about 3mm.

Since the periosteum adheres to bone tissue, imagine the bone as a chopping board. Now that the burger is stuck to the cutting board, flipping it over is like cutting it in half vertically from top to bottom, and then "scooping" it up and placing it at both ends of the cutting board cleanly. When cutting a hamburger, the cutting board under the burger is very hard, so the knife needs to be "tough", penetrating three layers and reaching the bone surface, so that the burger can be neatly divided into two pieces with minimal damage to the sandwich layer. If the bottom layer of bread is not cut through, it may hit the middle when shoveling, causing the sandwich layer to be scattered and cheese to overflow; Alternatively, it could be due to a portion of the bread sticking to the chopping board, which prevents the entire burger from being scooped up.
The exposed area of the flap
The Hamburg Model
02
Incision: Remember the 3 'cannot's'
The incision cannot be in the center, otherwise both the buccal and lingual flaps need to be opened.
The incision should not be too biased towards the buccal side, as insufficient keratinized gingiva on the buccal side can easily lead to peri implantitis in the later stage.
The incision should not be too close to the lingual side, otherwise the patient may lick the suture thread after suturing, causing the wound to crack open.
The incision is usually made at a position 2mm away from the tongue and palate in the center, so that only the lip and cheek flaps need to be opened. If the keratinized gingiva and bone mass are abundant, and the patient has good oral hygiene, it is recommended to use a ring cutter for minimally invasive implantation surgery. At this time, the first and second phases of surgery can be completed simultaneously (Figure 3).
Position of incision
03
Positioning: Consider 6 "directions"
What risk factors need to be considered before the implant is about to be implanted into the alveolar bone?
Upper (implant neck)
Regarding the main functional apex or the area near the central fossa of the jaw teeth.
Bottom (tip of implant)
The mandibular posterior region has important nerves and blood vessels, and the mental foramen area is relatively complex. So the planting location must not be too deep and a safe distance must be maintained. There is a maxillary sinus in the posterior maxillary region, be careful not to pass through the maxillary sinus.
Left (buccal side)
In areas with high aesthetic risk, sufficient lip bone tissue should be preserved during implantation to facilitate aesthetic repair.
Right (tongue and palate measurement)
After mandibular lingual injury, there is a risk of hematoma and suffocation for patients. There are incisions in the maxillary incisor area, and as there are nerve vessels inside the incisions, it is advisable not to affect them. However, even if the implant enters the incisions, there are no obvious adverse consequences, and accurate evaluation and weighing by dental physicians are needed.
Front (anterior area of missing teeth)
Partial tooth roots tilt towards the far center, so it is important to avoid damaging adjacent teeth during implantation. The implant can be tilted or placed backwards accordingly.
Posterior (area behind missing teeth)
Posterior teeth are generally used as reference points for implantation.

04
Planting: Don't panic when encountering the following "hand feel"
Feeling of disappointment
The surface cortical bone is very hard, but it fails instantly after breakthrough, which is more common in female patients with osteoporosis after menopause. In this situation, the fulcrum must be stable and do not apply too much pressure when drilling.
Cannot move
Type I bones are as solid as rocks and are commonly found in middle-aged men with strong physique.
I have encountered Super Class I bones twice before, remember to prepare more cooling saline and be patient, slowly drill. It should be noted that due to insufficient internal blood supply, vigorous drilling must not be used, otherwise excessive heat production may lead to bone necrosis and difficult recovery. More haste, less speed.

Author: Liu Siyi and Dong Yanmei

Department of Dentistry and Endodontics, Peking University Stomatological Hospital

summary
The functions of dental pulp tissue include: promoting the continuous development of young permanent tooth roots, acting as a biological sensor to produce defensive responses to external pathological stimuli, forming reactive or reparative dentin to prevent infection, and providing nutrition to teeth, reducing the occurrence of root fracture. Therefore, whether for young or adult permanent teeth, protecting and preserving dental pulp health is the primary principle of dental caries treatment. In the past, both domestically and internationally, for adult permanent teeth with caries induced pulp exposure, the principle was to remove the pulp for root canal treatment. This is because there is a lack of methods in clinical practice to determine the pulp status and infection range. However, clinical studies based on traditional concepts and techniques have shown that the long-term success rate of using calcium hydroxide as a pulp capping agent to treat adult permanent teeth with caries induced exposed pulp is only 13% to 59%. This makes it possible for some cases to preserve vital pulp, but due to a lack of confidence in successful preservation, they have to remove the pulp for root canal treatment.

In recent years, with the deepening of researchers' understanding of pulp biology and pulp histopathology, as well as the development of bioactive pulp capping agents and clinical treatment methods, the application of pulp preservation therapy in adult permanent teeth has been continuously increasing in related research and clinical applications. Research on dental pulp biology has found that adult dental pulp still has the potential for repair. When the pulp is locally damaged, the remaining pulp stem cells in the pulp tissue can differentiate into odontogenic like cells under the induction of pulp capping agents, producing new dentin to isolate external stimuli; Research on the pathology of dental pulp tissue shows that caries exposing the pulp does not necessarily mean irreversible changes have occurred in the pulp; Clinical studies have shown that the application of bioactive pulp capping agents greatly improves the success rate of pulp preservation therapy. Based on the above, the European Society of Endodontics in 2019 and the American Society of Endodontics in 2021 respectively published international consensus among dental pulp experts: it is recommended to use minimally invasive surgery to maintain pulp vitality in adult permanent teeth with exposed pulp due to caries. So, in clinical practice, how to determine whether adult permanent teeth can preserve vital pulp due to caries and exposed pulp? What methods should be used and how should they be handled to improve the success rate of treatment?

Case 1
Patient information: Male, 18 years old.
The chief complaint is a hole in the upper left posterior tooth for one month.
There is a hole in the left upper posterior tooth and food impaction in the current medical history for one month. It denies any pain caused by cold or heat stimulation, spontaneous pain, bite pain, or gum swelling and pain. There is no special medical or family history, and the whole body is healthy.
Oral examination showed a deep caries cavity near the middle surface, with a soft texture but no pulp hole exposed. The pain was (-) and there was no looseness. No redness or swelling was observed in the gums. Cold test for transient sensitivity. X-ray shows: The shadow of the 27 deep caries cavity is near the pulp, and no transmission shadow is seen around the periapical area (Figure 1).

Case 1 Patient 27 X-ray
Diagnose 27 reversible pulpitis.
The treatment process first involves using a rubber barrier to isolate the oral environment at the affected tooth site to prevent infection. Use sterile instruments to remove the necrotic material in the order of the cave wall, cave bottom, and near the pulp. After removing the impurities, a pulp hole can be observed, accompanied by bright red bleeding (Figure 2A). Use a 2.5% sodium hypochlorite cotton ball to gently press the exposed pulp hole for one minute to stop bleeding. After hemostasis, observe the exposed pulp hole under a microscope. The diameter of the exposed pulp hole is about 2mm, and the pulp tissue is uniform and continuous, indicating that the pulp tissue is in a non inflammatory state (Figure 2B). Using bioceramic materials for direct pulp capping (Figure 2C), a thin layer of flowing resin was applied over the pulp capping agent, followed by immediate composite resin bonding repair surgery (Figure 2D). After surgery, the affected tooth showed no symptoms and normal function. Upon examination, it was found that the 27 filling bodies were intact, with tenderness (-) and no looseness. There was no redness or swelling in the gums, and the cold test was normal. The X-ray showed the formation of a dentin bridge under the pulp capping agent one year after surgery. Follow up examinations at 2 and 3 years after surgery showed clear images of the pulp cavity and root canal without significant reduction, and no transmission shadow was observed around the periapical area (Figure 3).

Figure 2: Treatment Process of Patient 1. A is for removing impurities; B is used to stop bleeding by exposing the medullary foramen; C is a bioceramic material used for direct marrow capping; D is a composite resin for immediate bonding and repair

Comparison of X-ray images before and after treatment for patient 1. A is the preoperative film; B is one year after surgery; C is two years after surgery; D is 3 years after surgery

Case 2
Patient information: Female patient, 21 years old.
Chief complaint: sensitivity to cold stimulation in the upper right posterior tooth for 2 weeks.
Present medical history: Over the past 2 weeks, the right upper posterior tooth has been sensitive to cold stimulation, and there is no evidence of spontaneous pain, nocturnal pain, bite pain, or gum swelling. There are no special medical or family histories. Full body health.

Oral examination showed a deep caries cavity in the mesial area, with a soft texture and no exposed medullary foramen. The pain was (-) and there was no looseness. There was no redness or swelling in the gums, and the cold test showed transient sensitivity. X-ray shows that there is a shadow of 16 near the mid to deep caries cavity near the pulp, and widening of the periapical membrane can be seen at the far buccal root. No transmission shadow is observed around the periapical area (Figure 4).

Case 2 Patient 16 X-ray film

Diagnose 16 reversible pulpitis.

During the treatment process, the rubber barrier on the affected tooth was first used to isolate the infection, and sterile instruments were used to remove the necrotic material. After that, there was a lot of bright red bleeding at the exposed pulp hole. A 2.5% sodium hypochlorite cotton ball was gently pressed on the pulp hole for two minutes to stop the bleeding. At this time, the cross-section of the pulp tissue was observed under a microscope under magnification, and a strip-shaped pulp area about 3mm long was visible. The exposed pulp tissue surface had red congested areas and light yellow ischemic areas, and the pulp tissue was discontinuous. Use a high-speed turbine ball drill to remove a small amount of pulp tissue from the exposed pulp hole, and further observe the condition of the cross-section. The cross-section shows a continuous and uniform healthy pulp texture similar to jelly. After using bioceramic materials for pulp capping, cover with a small amount of flowing resin, and then perform direct bonding repair with composite resin (Figure 5). After surgery, the affected teeth were asymptomatic and functioning normally. Oral examination showed that the 16 filling bodies were intact, with tenderness (-) and no looseness. There was no redness or swelling in the gums, and the cold test was normal. One year after surgery, X-ray images of the medullary cavity and root canal remained clear, while no widening of the periodontal ligament was observed at the far buccal root apex and no transmission shadow was observed at the periapical area (Figure 6).

Case 2: Treatment Process of Patient
Comparison of X-ray films of patient 16 before surgery, immediately after surgery, and 1 year after surgery in case two

Case analysis
Selection of indications and treatment methods

According to the third edition of "Endodontics" published by Peking University Medical Press in 2022, the indications for direct pulp capping surgery on adult permanent teeth after pulp exposure due to caries are preoperative diagnosis of deep caries or reversible pulpitis, and dotted pulp exposure after removing the decayed material during surgery. However, the pulp status and restoration method of the affected tooth should also be considered when selecting clinical cases; The indication for adult permanent teeth undergoing pulpotomy after pulp exposure due to caries is that if the degree of pulp inflammation can be clinically determined and infection and damage can be controlled during the procedure, pulpotomy can be attempted to preserve the vital pulp. Therefore, the key to determining whether the living pulp of adult permanent teeth can be preserved when the pulp is exposed due to caries is the assessment of the pulp status. Before surgery, the pulp status can be preliminarily determined based on the symptoms of the affected tooth and clinical examination. During clinical examination, attention should be paid to the results of pulp vitality testing. Dental pulp vitality testing can provide a basis for preliminary assessment of the pathological status of dental pulp. Literature shows that for deep caries or reversible pulpitis, there is a high consistency between preoperative clinical diagnosis and pulp histological status. During the operation, a magnifying device can be used to observe the pulp tissue and whether there is bleeding, in order to further determine the pulp status. If there is dark red without blood, yellow translucent red or alternating red and white at the exposed pulp hole, or if there is visible dentin debris and purulent exudation, it indicates that the pulp has at least partially necrotic, and direct pulp capping surgery is not suitable for these situations. In a treatment recommendation for teeth with caries and exposed pulp published by dental pulp histopathology experts Ricucci et al., for teeth diagnosed with deep caries or reversible pulpitis before surgery, if exposed pulp appears during surgery, physicians need to further assess the condition of the exposed pulp hole. If the following conditions are met, direct pulp capping surgery can be performed: ① hard dentin around the exposed pulp hole; ② The bleeding is bright red and can be stopped within two minutes; ③ Good continuity of dental pulp tissue; ④ There are no dentin fragments in the pulp tissue. If not satisfied, pulpotomy can be attempted. The criteria for determining the termination point of pulp cutting are: bleeding on the pulp section is bright red and can be stopped within 2 minutes, and the tissue continuity of the pulp section is good.

The selection of treatment methods is based on the analysis of the above indications and treatment methods. It can be concluded that case one meets the indications and case selection criteria for direct pulp capping surgery, and therefore undergoes direct pulp capping surgery to preserve the vital pulp; In case two, a small amount of necrotic pulp tissue was observed under a microscope, so partial coronal pulpotomy was used to preserve the living pulp. So what is the success rate of adult permanent tooth pulp preservation treatment for caries induced exposed pulp? The table on the right shows clinical studies on direct pulp capping surgery for adult permanent teeth with caries induced exposed pulp from 2016 to present. The results showed that when using bioceramic pulp capping agents, the success rate was 83% to 90%, but when using calcium hydroxide as the pulp capping agent, the success rate significantly decreased to only 52% to 78%.

Success rate of direct pulp capping surgery for adult permanent teeth with surface caries and exposed pulp

Professor Dong Yanmei's research group at Peking University Stomatological Hospital conducted a clinical observation on the efficacy of bioceramic material direct pulp capping surgery for adult permanent teeth with exposed pulp due to caries. This study selected teeth diagnosed with deep caries or reversible pulpitis before surgery and performed direct pulp capping surgery using iRootBP Plus. 50 cases were followed up after surgery for 1 to 4 years to observe the efficacy. The results showed that all 45 cases successfully preserved vital pulp, with success rates of 98%, 89%, and 81% at one year, two years, and three years or more after surgery, respectively.

At present, there is limited literature on the method of partial coronal pulpotomy for adult permanent teeth with caries induced exposed pulp. Existing literature shows that the success rate is 85% to 96% when using bioceramic pulp capping agents, but when using calcium hydroxide as the capping agent, the success rate significantly decreases to only 43%. Therefore, although there is a certain success rate of pulpotomy for adult permanent teeth with caries induced exposed pulp, there is currently a lack of sufficient high-quality clinical evidence. Partial coronal marrow cutting surgery requires the use of sterile and sharp spoons, ball drills, etc. for the cutting of the coronal marrow. The literature suggests that the resection range should be from 1.5 to 3mm below the exposed pulp section. In practical applications, the local infection or inflammation of the pulp at the exposed pulp hole can be removed by combining the patient's clinical symptoms, signs, intraoperative hemostasis, and microscopic judgment of the pulp tissue.

Clinical treatment points for preserving vital pulp

Both textbooks and literature point out that one of the key points for preserving vital pulp is to control intraoperative infections. In both cases in this article, rubber barriers were used to avoid reinfection, and the principle of first removing the wall of the cavity, then the bottom of the cavity, and finally near the pulp was followed in the order of removing decay. The instruments used in the treatment process were sterile, sharp, and minimally invasive. 2.5% sodium hypochlorite was used for disinfection and hemostasis, and the entire process was operated under a microscope to avoid further damage to the pulp tissue.

Next is the selection of pulp capping agents. Literature shows that compared to calcium hydroxide, silicon calcium materials have better long-term efficacy, while the success rate of using calcium hydroxide decreases over time, resulting in poorer long-term efficacy. All silicon calcium based pulp capping materials exhibit good biocompatibility, which can promote the differentiation of dental pulp cells into dentin, facilitate the formation of dentin bridges, and rarely cause inflammatory reactions. Currently, no material has shown significant advantages.

Animal research by Liu Siyi et al. found that when using bioceramic pulp capping agents, a complete dentin bridge structure can be formed beneath the pulp capping material in both direct pulp capping and coronal pulp cutting models. As mentioned earlier, the overall success rate of using bioceramic materials for direct pulp capping surgery is about 90%. Therefore, both cases in this article selected bioceramic materials with biological activity for pulp capping, hoping to promote the healing of damaged pulp tissue.

The textbook points out that the pulp capping material should cover the edge of the pulp section by about 1mm and have a thickness of 1-2mm. After pulp capping, a small amount of light waves or flowing resin can be used to cover the pulp capping material, but at least 1.5mm of dentin bonding interface should be retained around it to ensure the direct bonding effect of the composite resin afterwards. Tight sealing of the crown after marrow capping is also an important condition for successful marrow preservation treatment. If the crown is not tightly sealed and micro leaks occur, bacteria can infect the remaining pulp tissue below. Literature shows that delaying permanent repair increases the risk of failure in pulp preservation treatment. Therefore, in both cases of this study, immediate composite resin bonding repair was performed after pulp capping to ensure tight coronal closure.

Case review
Professor Dong Yanmei: Healthy dental pulp tissue is of great significance for the long-term maintenance of tooth function, so preserving dental pulp vitality as much as possible has always been the primary principle of dental pulp treatment. In recent years, the preservation treatment of adult permanent teeth with caries induced pulp exposure has been increasingly carried out in clinical practice. However, many problems have also been exposed in practice, such as the degree of decay, selection of indications, and pulp treatment after pulp exposure. At the end of 2019, the Department of Endodontics and Dentistry at Peking University Stomatological Hospital initiated the revision work of the third edition of "Endodontics and Dentistry" published by Beijing Medical University. The content of this book on pulp preservation treatment referred to international cutting-edge research evidence and treatment guidelines, and made significant updates to the indications, case selection, and clinical treatment methods for pulp preservation. This article provides a very good explanation of the selection of indications for pulp preservation therapy in clinical practice, as well as standardized intraoperative management. The key to pulp preservation treatment lies in determining the status of the dental pulp. It is recommended to choose a tooth with a preoperative diagnosis of normal pulp or reversible pulpitis, no self initiated pain before surgery, no percussion pain on clinical examination, normal or transient sensitivity on temperature testing, and no periapical abnormalities on X-ray examination. The criteria for determining the pulp status during surgery are pulp exposure, bleeding, and hemostasis. If the pulp bleeding is small, bright red in color, and can be stopped within 1-5 minutes, direct pulp capping treatment can be attempted. If the active bleeding of the dental pulp is difficult to stop, or the color is dark red, and even exudate or pus can be seen, it indicates that there is severe inflammation of the dental pulp. At this time, it is not advisable to directly cover the pulp, and partial pulpotomy can be attempted. The method of observing the morphology of dental pulp tissue under a microscope introduced by Deputy Chief Physician Liu Siyi is also a good way to determine the status of dental pulp. It is generally believed that the larger the range of pulp exposure, the more severe the degree of pulp tissue infection, and the worse the prognosis of pulp preservation treatment. Therefore, we recommend in textbooks that direct pulp capping surgery is more suitable for pulp hole diameters within 1mm. If the diameter exceeds 2mm, direct pulp capping surgery is not recommended and partial pulp cutting surgery can be attempted.

Minimizing further damage to dental pulp tissue as much as possible is also an important step in the successful preservation of vital pulp. These two cases demonstrate very well how to strictly control infection during surgery and strive for minimally invasive treatment. Postoperative patients may experience brief discomfort and hidden pain, which can often be relieved on their own. If the affected tooth experiences severe spontaneous pain, nighttime pain, and other symptoms, indicating that the condition has progressed to irreversible pulpitis, root canal treatment should be switched. Follow up should also be conducted after surgery. The general time for postoperative follow-up can be 3 months, 6 months, or 1 year.

The preservation of vital pulp is of great significance for the long-term functioning of teeth. Only by correctly assessing the pulp status, effectively controlling infections and injuries, can the treatment of vital pulp preservation be successful.

It is common for periapical periodontitis to occur after root canal treatment in clinical practice. These patients can undergo root canal re treatment or micro root canal surgery (root apex resection+root canal filling). How do people usually choose these two methods? Can you predict which method has a higher success rate for teeth with different basic conditions?

It is particularly important to consider how the use of post core crowns for tooth restoration after the initial root canal treatment will affect the subsequent treatment? A recent clinical study has provided some reasonable and unexpected reference evidence.

Overall results: Root apex surgery is superior to root canal retreatment

In a retrospective study from Norway, 351 teeth with periapical periodontitis after root canal treatment underwent non-surgical root canal re treatment and 107 teeth underwent root canal surgery, with a follow-up period of over 11 months. The results showed that the success rate of root apex surgery was 77.6%, significantly higher than the 65.5% of non-surgical re treatment (P=0.032).

The study was published online on March 23, 2023 in the International Journal of Endodontics (Int Endod J).

Treatment standards: Both root canal retreatment and microsurgical root canal procedures follow the guidelines of the European Society of Endodontics (ESE). Except for two cases where silver mercury was used as the backfill material for root tip surgery, all others were made of bioceramics.

Efficacy criteria: For non-surgical cases, the periapical index (PAI) score is used, and for surgical cases, the Rud/Molven standard score is used, which are divided into treatment success, uncertainty, and failure, respectively; Tooth extraction or periapical sinus formation are considered failures.

But the post-treatment effect after the root canal pile seems to have the opposite conclusion

Existence of root canal piles: non-surgical re treatment is more advantageous

Although overall, root canal surgery is more effective than non-surgical re treatment, for teeth with root canal piles, the success rate of non-surgical treatment is slightly better than surgery (30 teeth each, 73.3% vs. 66.7%, P=0.111).

The success rate of root apex surgery for teeth without root canal piles is still higher than non-surgical re treatment (P=0.012), consistent with the overall situation.
The advantages or significance of this conclusion currently reflected in clinical practice are not sufficient, possibly because if teeth that have been treated with root canal piles need to be treated again, doctors seem to choose root canal surgery more often

Multiple root apex surgeries for maxillary anterior teeth and premolars?

By separately counting the types of teeth receiving the two treatments, it can be found that there are significant differences in the methods used by physicians for anterior teeth/premolars/molars. Root canal surgery is more common for maxillary anterior teeth and premolars, while non-surgical root canal re treatment is more common for mandibular molars (P<0.001).

Especially the maxillary premolars were the teeth with the most root canal posts (15 teeth), of which 12 teeth underwent root canal surgery (P=0.004). However, non-surgical success rates are higher for teeth with a root canal.

Among the 458 teeth without root canal piles, the number of non-surgical teeth (321) was significantly higher than the number of surgical teeth (77) (P=0.001). However, the success rate of root apex surgery is higher.

So, when receiving patients undergoing root canal therapy, should more consideration be given to including root canal surgery? When facing the treatment of teeth with a root canal, should non-surgical methods be prioritized?

The effect of root canal re treatment is affected by age

The evaluation results of the therapeutic effect also showed that for non-surgical cases, the effectiveness of root canal retreatment was significantly affected by age and preoperative PAI score: the prognosis of elderly people over 50 years old was worse (P=0.015), and the prognosis of those with higher preoperative PAI scores was worse (P<0.001); The gender and tooth type of the patient will not affect the effectiveness of further treatment.

For cases of root apex surgery, no factors were found in this study that could affect the treatment outcome (all P>0.05).

The researchers explained that root canal therapy for teeth with root canal piles is more effective than root canal surgery. This conclusion may be influenced by various factors, such as tooth position, periodontal condition, previous root filling quality, size of root canal piles, and distance from the root apex. The removal of root canal piles by ultrasound has been widely, safely, and effectively applied in clinical practice, which is highly beneficial for reducing the risks of root fracture, perforation, and residual filling materials. It is a powerful guarantee for the success of root canal re treatment.
How will dentists consider and choose between root canal surgery or root canal re treatment when dealing with cases of periapical periodontitis after root canal filling in the future? Welcome to add discussion in the comment section~

Title: Treatment outcome of surgical and non surgical endodontic retreat of youth with acute periodontitis