Clinical Research
Outcome of Direct Pulp Capping with Mineral Trioxide Aggregate: A Prospective Study Miguel Seruca Marques, DDS, Paul R. Wesselink, DDS, PhD, and Hagay Shemesh, DMD, PhD Abstract Introduction: The aim of this experimental study was to assess the outcome of direct pulp capping with mineral trioxide aggregate (MTA) after complete excavation of caries in permanent dentition with a 2-visit treatment protocol. Methods: Sixty-four teeth with deep carious lesions were consecutively selected. The mean age of the patients was 36.1 15 years. An initial diagnosis of deep caries, with no irreversible pulp involvement, was made. Excavation of caries was performed under a rubber dam and operating microscope magnification. White MTA was applied, and a provisional restoration was placed. At the following appointment, positive sensibility testing and the MTA setting were confirmed. Bonded composite restorations were placed afterward. The patient was recalled at least 1 year after treatment for clinical and radiographic control. Outcome was described as success or failure. Success was defined as lack of complaints from the patient, positive reaction to cold testing, no sensitivity to percussion, and no widening of the periodontal ligament on the recall periapical radiograph. Results: Forty-six teeth (77.9%) were recalled after 3.6 years (standard deviation = 1.1 years). The overall success rate was 91.3%. The success rate in occlusal caries was 100% and 89.7% in proximal caries (difference = 10.3%; 95% confidence interval [CI], 8.5–89.1). The success rate in initial caries was 94.7% and 88.9% in secondary caries (difference = 5.8%; 95% CI, 48.1 to 59.7). The success rate in patients younger than 40 years was 100% and 80% in patients aged 40 years or older (difference = 20%; 95% CI, 4.2–35.8). Conclusions: Direct pulp capping with MTA after pulp exposure during excavation of deep caries could maintain pulp vitality in permanent teeth when a 2-visit treatment protocol is observed. (J Endod 2015;-:1–6)
Key Words Complete excavation, direct pulp capping, mineral trioxide aggregate
T
he first description of a pulp capping procedure was the application of a cap of lead foil to an exposed pulp by Pfaff (1756) (1, 2). Vital pulp therapy in the form of pulp capping and pulpotomy has long been recognized as a procedure aimed to maintain pulp vitality after caries exposure (3). In deep carious lesions, inflammation in superficial layers of the pulp, especially subjacent to the region of the involved dentinal tubules, is more pronounced compared with deeper layers, whereas pulp tissue in the root canal usually remains normal, except for the presence of dilated blood vessels (3, 4). Pulpal healing and repair after direct pulp capping or partial pulpotomy was reported in in vivo studies after the removal of caries (6) or exposure after accidental trauma (7). Optimal prognosis of vital pulp therapy is based on the elimination of etiologic factors with complete removal of diseased and contaminated tissues (6). When pulp exposure occurs, immediate direct pulp capping is preferred to reduce the risk of infection and further damage to the pulp. The most studied material for direct pulp capping is calcium hydroxide (CH) in a variety of formulations (pure and fast setting). However, the success rate of direct pulp capping with fast-setting CH-based cements varied widely between 31.8% after 1 year (8) and 72.7% after 10 years (9). Mineral trioxide aggregate (MTA) has been investigated as a material for direct pulp capping during recent years and showed superior results when compared with CH. MTA reduces inflammation, hyperemia, and necrosis levels. It also creates thicker dentin bridges and minimal tunnel defects, and the apposition of dentin is faster (10). MTA resists bacterial leakage and may provide protection for the pulp, allowing repair and continued pulp vitality (6). The disadvantages of MTA are discoloration (6), difficult manipulation, slow setting time (11), and cost of the material. The purpose of this experimental study was to assess the treatment outcome of deep caries lesions treated with MTA direct pulp capping. The following parameters were addressed: 1. Pulp sensibility 2. Tooth discoloration 3. Caries recurrence The tested null hypotheses were that the following parameters do not influence the outcome of direct pulp capping with MTA: bleeding or no bleeding during caries excavation, occlusal or proximal caries, initial or secondary caries, and age younger or older than 40 years.
From the Academic Centre for Dentistry, Amsterdam, the Netherlands. Address requests for reprints to Dr Miguel Seruca Marques, Department of Cariology, Endodontology, and Pedodontology, Academic Center for Dentistry Amsterdam, Gustav Mahlerlaan 3004, 1081LA Amsterdam, Netherlands. E-mail address: [email protected] 0099-2399/$ - see front matter Copyright ª 2015 American Association of Endodontists. http://dx.doi.org/10.1016/j.joen.2015.02.024
JOE — Volume -, Number -, - 2015
Methods All patients in this study were selected consecutively from the daily general private practice of 1 of the authors (M.M.) over a period of 3 years between 2008 and 2011. All patients had completed a detailed clinical history questionnaire, bite-wing radiographs, percussion, and cold thermal testing (EndoFrost; Roeko, Langenau, Germany). Over this period, a total of 59 patients were treated after the diagnosis of extensive primary or secondary deep caries in 64 teeth in which pulp exposure was anticipated because of caries extension on radiographic or clinical evaluation. Eventually, 64 permanent teeth were treated: 5 incisors, 17 premolars, and 42 molars; 38 were maxillary,
Direct Pulp Capping with MTA
1
Clinical Research and 26 were mandibular. The patient sample consisted of 32 females and 27 males with a mean age of 36.1 years (standard deviation [SD] = 15.1). All participants or legal guardians were asked to sign an informed consent form in which the treatment was briefly explained. The inclusion criteria were permanent teeth with caries, a positive cold test, the absence of spontaneous and lingering pain, the absence of percussion pain, and the absence of sinus tract or swelling. One operator (M.M.) completed all treatment procedures, with the exception of 2 definitive bonded restorations that were performed by another general practitioner at the same practice. All procedures were performed under a rubber dam and local anesthesia of 4% articaine with 1:100,000 epinephrine (ARTINIBSA; Laboratorios Inibsa SA, Barcelona, Spain). Caries excavation was performed under 6 to 16 magnification (DFV Vasconcellos MC-M1232; DFV, Rio de Janeiro, Brazil) using caries detector dye (Sable seek or Seek; Ultradent Products GmbH, Cologne, Germany) applied with a disposable brush tip (Black mini brush tip, Ultradent Products GmbH). High-speed round (801.314) diamond burs with medium grit 014, 016, or 018 (Komet Dental, Lemgo, Germany) on an air turbine with water and air spray coolant were used for enamel removal. Round steel (H1SE.204) slow-speed burs 014, 016, or 018 (Komet Dental) or LN burs 014, 016, or 018 (Dentsply Maillefer, Ballaigues, Switzerland) with water and air spray coolant and sharp hand excavators (EXCE2 and EXCE3; Hu-Friedy, Chicago, IL) were used for caries removal. Caries excavation continued even after pulpal exposures occurred and was complete when dentin offered resistance to hand excavation with a sharp excavator as per final inspection. In all cases in which pulp bleeding occurred, hemostasis was achieved with water from a 2-way syringe of the dental unit and occasionally pressure applied with dry cotton pellets. Subsequently, the surrounding dentin was gently air-dried with a 2-way syringe until all excess water had been removed. White MTA (ProRoot; Dentsply Tulsa Dental, Tulsa, OK) mixed according to the manufacturer’s instructions, 3:1 powder-to-liquid ratio, was applied in a thin layer of 1.5 mm over the exposure site and surrounding dentin with the aid of a double-ended medium 1.2-mm/1.6-mm ball burnisher (Henry Schein Inc, Melville, NY), leaving some circumferentially dentin available for bonding. Ten minutes after the direct capping procedure, a provisional restoration with zinc oxide/zinc sulfate–based cement (Coltosol F; Coltene/Whaledent, Altst€atten, Switzerland) was placed directly over the MTA. At the following appointment, 4 to 12 weeks later, if spontaneous pain complaints were reported, cold testing was negative, and/or
percussion resulted in a painful reaction, root canal treatment was performed. Otherwise, provisional restorations were removed with round steel (H1SE.204) slow-speed burs 014, 016, or 018 (Komet Dental) or LN burs 014, 016, or 018 (Dentsply Maillefer) with water and air spray coolant. MTA setting was confirmed and its color determined. A Palodent sectional matrix (Dentsply DeTrey GmbH, Konstanz, Germany) was adjusted, and a 35% phosphoric etchant solution (UltraEtch, Ultradent Products GmbH) for 30 seconds was applied on the enamel, dentin, and MTA surface and was rinsed and air-dried for 5 seconds. A light-curing adhesive agent (OptiBond Solo; KerrHawe Neos, Orange, CA) was applied with a microbrush in a brushing motion for 20 seconds, and excesses were blown out. The bonding agent was light cured (Bluephase G2 LED; Ivoclar Vivadent AG, Schaan, Liechtenstein) for 20 seconds, and all cavities were filled with composite (Tetric evo Ceram, Ivoclar Vivadent AG) in several layers and light cured for 40 seconds. Patients were recalled yearly for clinical tests and periapical radiographs. Success was defined as a positive cold test, no pain on percussion, and no widening of the periodontal ligament on the periapical radiograph. All radiographs were acquired using a dental radiograph unit (Philips Oralix 65; Philips, Eindhoven, The Netherlands) set at 65 kVp, 7.5 mA, and 0.2 seconds. A digital dental sensor (Visualix-1; Gendex Dental Systems, Milan, Italy) was used to capture all digital radiographs with a positioning holder using a perpendicular technique. The digital radiographs were visualized with imaging software (VixWin, Gendex Dental Systems) on a personal computer (ASUS Eee PC 1201 PN Netbook; ASUSTek Computer Inc, Taipei, Taiwan). One operator (M.M.) diagnosed recurrent caries through clinical and radiographic evaluation. When in doubt, the case was classified as having recurrent caries. The same operator classified discoloration subjectively as either discolored or not discolored. When in doubt, the case was classified as discolored. Data entry and analysis were performed with a statistical software package (SPSS 21.0; SPSS Inc, Chicago, IL). The Fisher exact test and the Kaplan-Meier method were used for analysis with a significance level of P < .05.
Results This sample consisted of 12 teeth with occlusal caries and 52 with proximal caries, of which 26 were primary caries and 38 secondary caries. On the first appointment, pulp bleeding during caries excavation occurred in 29 of the 64 teeth; 92.2% of the patients (59 teeth) returned for the second appointment. In 3 of 5 teeth that were lost to recall, no bleeding was detected during the first appointment, and in the
TABLE 1. Outcome of Direct Pulp Capping with Mineral Trioxide Aggregate According to Study Variables: Bleeding, Caries Location, Caries Treatment, and Age Studied variables (n = analyzed teeth) Success Pulp vitality without apical radiolucency, n (%) Failure Spontaneous pain, n (%) No pulp vitality with apical radiolucency, n (%) Difference between groups, % (95% CI) P value
Bleeding
Caries treatment
Caries location
Age
Present (n = 21)
Absent (n = 25)
Initial (n = 19)
Secondary (n = 27)
Occlusal (n = 7)
Proximal (n = 39)
.05
>.05
>.05
.05) (Fig. 1). The overall probability of pulp survival at 4 years was 87.3%.
Discussion The aim of this experimental clinical study was to evaluate the outcome of direct pulp capping using a specific 2-step protocol with MTA, and, thus, no control groups using either calcium hydroxide or indirect pulp capping were included. Incomplete caries removal was not considered as a treatment option for these patients because the quality of several studies that support this practice is low (12, 13). In an animal study, Cox et al (14) showed that a total of 192 dentin bridges formed against the fast-setting CH in 235 pulp-capped teeth, of which 41% were associated with recurring pulp inflammation or necrosis and were always associated with inflammatory cells and stained bacterial profiles. Dentin bridge formation after vital pulp therapy does not guarantee success. Histologic sections of healthy human or animal teeth capped with fast-setting CH-based cements showed the formation of tunnel defects in the calcified bridge (10, 14). Tunnel defects have also been observed in a carious human tooth capped with CH powder (15). In a multicenter randomized clinical trial, pulp capping of deep carious–exposed permanent teeth with fast setting CH reported a success rate of 31.8% after 1 year (8). Healthy teeth capped with MTA presented hard tissue barriers of steadily increasing length and thickness accompanied by healthy pulp tissue (10). Because of these advantages of MTA over CH and in order not to dilute the outcome of the result by dividing the limited available patients in 2 groups, no controls with CH or other materials were included. Studies on pulp capping of carious-exposed permanent teeth with MTA have reported high success rates, which ranged from 93%–98% (6, 16). The success rate of 91.3% in our study compares with the results of previous studies. This study has also some bias potential because the same operator performed treatments and follow-up procedures although a similar methodology was used in several vital pulp therapy studies (6, 17). The overall probability of pulp survival at 4
Direct Pulp Capping with MTA
3
Clinical Research
Figure 4. Treatment of the right first maxillary molar. (A) Initial radiograph with deep caries, (B) initial clinical photograph with extensive occlusomesial caries, (C) pulp exposure with bleeding from the mesiobuccal pulp horn, (D) MTA direct pulp capping over the mesiobuccal pulp horn and the surrounding dentin, (E) follow-up radiograph after 23 months, and (F) follow-up clinical photograph after 23 months.
years using the Kaplan-Meier survival probability test was 87.3%. This result was lower than the 94.87% reported in a previous study (6). This difference could be explained by several factors. In the former study, all teeth exhibited initial deep caries and no prior restorations, whereas in the current study, initial and secondary caries were treated. The age interval in the former study (7–45 years) was different than in the current study (8–68 years). 4
Marques et al.
Factors such as age, caries history, location, and blood clotting between the pulp and the capping material were already reported to have an influence on treatment outcome (1). Furthermore, a positive correlation was found between caries location and inflammatory pulp extension (18). In this study, caries location and pulp bleeding were explored as outcome predictors because of their potential importance for the success of pulp capping. JOE — Volume -, Number -, - 2015
Clinical Research In a clinical trial, a lower success rate of 56.2% was reported after direct pulp capping with MTA (19). However, no attempt was made to fully remove carious dentin as soon as pulpal bleeding was observed. The success of vital pulp therapy may depend on the complete removal of all disintegrated tissue (5). Controlling the infection is apparently a key point for clinical success of direct pulp capping (20). In our study, no case was excluded based on the amount of bleeding because this factor as an outcome predictor is controversial (21). In some cases, it was evident that MTA served to ‘‘soak up’’ oozing unclotted blood, and immediate staining of MTA was evident after 10 minutes (Fig. 2). Bleeding from the exposed pulp for longer than 5 and up to 10 minutes has previously been used as a threshold for reversible versus irreversible pulpitis classification (1, 6). Clinical trials verifying this threshold are lacking. In the current study, no attempt was made to rinse the pulp exposure with saline or a disinfectant, but instead water from the dental unit was used. Because the procedures were performed using nonsterile cooling water from the air turbine and the slow-speed contra-angle handpiece, it did not seem logical to use any specific substances for pulp disinfection. Furthermore, dentin surfaces treated by sodium hypochlorite may inhibit the differentiation of odontoblasts from dental pulp stem cells (20), and chlorhexidine may inhibit MTA setting (22). The tooth discoloration rate in this study was 13.6% with subjective assessment by 1 observer. It has been reported that vital pulp therapy with white MTA can result in discoloration (23). Pulp bleeding controlled with sodium hypochlorite may potentiate discoloration (24). Although in the current study the pulp was rinsed with water from a dental unit 2-way syringe, still some cases of discoloration were observed. Moreover, after removal of the provisional restoration, the surface color of MTA was changed from white to gray in all cases (Fig. 3). Bonded restorations and curing light promote an oxygen-free environment and may be responsible for the discoloration in our study (25). MTA usage in the esthetic zone should be done cautiously (23). It was recommended to temporarily place a moist cotton pellet in direct contact with MTA and leave it in until the follow-up appointment because moisture assists in the hydration of MTA from a colloidal gel that solidifies to a hard structure in approximately 3 to 4 hours (22). In the current study, no cotton pellet was used, and the MTA hardened in every case, suggesting that the moisture from the pulp was enough for the setting in vital pulp therapy procedures (26). This experimental study used a 2-appointment protocol for direct pulp capping with MTA (Fig. 4A–F). The best evidence available at the time of the study used this same protocol (6), and there is only limited evidence that a single-appointment protocol could give similar results (27). The hypothesis that young pulps with open apices and abundant blood supply will heal more often than the mature pulp with narrowed apices and poor blood supply (28) was only shown in the current study when 2 age groups (
Outcome of Direct Pulp Capping with Mineral Trioxide Aggregate: A Prospective Study Miguel Seruca Marques, DDS, Paul R. Wesselink, DDS, PhD, and Hagay Shemesh, DMD, PhD Abstract Introduction: The aim of this experimental study was to assess the outcome of direct pulp capping with mineral trioxide aggregate (MTA) after complete excavation of caries in permanent dentition with a 2-visit treatment protocol. Methods: Sixty-four teeth with deep carious lesions were consecutively selected. The mean age of the patients was 36.1 15 years. An initial diagnosis of deep caries, with no irreversible pulp involvement, was made. Excavation of caries was performed under a rubber dam and operating microscope magnification. White MTA was applied, and a provisional restoration was placed. At the following appointment, positive sensibility testing and the MTA setting were confirmed. Bonded composite restorations were placed afterward. The patient was recalled at least 1 year after treatment for clinical and radiographic control. Outcome was described as success or failure. Success was defined as lack of complaints from the patient, positive reaction to cold testing, no sensitivity to percussion, and no widening of the periodontal ligament on the recall periapical radiograph. Results: Forty-six teeth (77.9%) were recalled after 3.6 years (standard deviation = 1.1 years). The overall success rate was 91.3%. The success rate in occlusal caries was 100% and 89.7% in proximal caries (difference = 10.3%; 95% confidence interval [CI], 8.5–89.1). The success rate in initial caries was 94.7% and 88.9% in secondary caries (difference = 5.8%; 95% CI, 48.1 to 59.7). The success rate in patients younger than 40 years was 100% and 80% in patients aged 40 years or older (difference = 20%; 95% CI, 4.2–35.8). Conclusions: Direct pulp capping with MTA after pulp exposure during excavation of deep caries could maintain pulp vitality in permanent teeth when a 2-visit treatment protocol is observed. (J Endod 2015;-:1–6)
Key Words Complete excavation, direct pulp capping, mineral trioxide aggregate
T
he first description of a pulp capping procedure was the application of a cap of lead foil to an exposed pulp by Pfaff (1756) (1, 2). Vital pulp therapy in the form of pulp capping and pulpotomy has long been recognized as a procedure aimed to maintain pulp vitality after caries exposure (3). In deep carious lesions, inflammation in superficial layers of the pulp, especially subjacent to the region of the involved dentinal tubules, is more pronounced compared with deeper layers, whereas pulp tissue in the root canal usually remains normal, except for the presence of dilated blood vessels (3, 4). Pulpal healing and repair after direct pulp capping or partial pulpotomy was reported in in vivo studies after the removal of caries (6) or exposure after accidental trauma (7). Optimal prognosis of vital pulp therapy is based on the elimination of etiologic factors with complete removal of diseased and contaminated tissues (6). When pulp exposure occurs, immediate direct pulp capping is preferred to reduce the risk of infection and further damage to the pulp. The most studied material for direct pulp capping is calcium hydroxide (CH) in a variety of formulations (pure and fast setting). However, the success rate of direct pulp capping with fast-setting CH-based cements varied widely between 31.8% after 1 year (8) and 72.7% after 10 years (9). Mineral trioxide aggregate (MTA) has been investigated as a material for direct pulp capping during recent years and showed superior results when compared with CH. MTA reduces inflammation, hyperemia, and necrosis levels. It also creates thicker dentin bridges and minimal tunnel defects, and the apposition of dentin is faster (10). MTA resists bacterial leakage and may provide protection for the pulp, allowing repair and continued pulp vitality (6). The disadvantages of MTA are discoloration (6), difficult manipulation, slow setting time (11), and cost of the material. The purpose of this experimental study was to assess the treatment outcome of deep caries lesions treated with MTA direct pulp capping. The following parameters were addressed: 1. Pulp sensibility 2. Tooth discoloration 3. Caries recurrence The tested null hypotheses were that the following parameters do not influence the outcome of direct pulp capping with MTA: bleeding or no bleeding during caries excavation, occlusal or proximal caries, initial or secondary caries, and age younger or older than 40 years.
From the Academic Centre for Dentistry, Amsterdam, the Netherlands. Address requests for reprints to Dr Miguel Seruca Marques, Department of Cariology, Endodontology, and Pedodontology, Academic Center for Dentistry Amsterdam, Gustav Mahlerlaan 3004, 1081LA Amsterdam, Netherlands. E-mail address: [email protected] 0099-2399/$ - see front matter Copyright ª 2015 American Association of Endodontists. http://dx.doi.org/10.1016/j.joen.2015.02.024
JOE — Volume -, Number -, - 2015
Methods All patients in this study were selected consecutively from the daily general private practice of 1 of the authors (M.M.) over a period of 3 years between 2008 and 2011. All patients had completed a detailed clinical history questionnaire, bite-wing radiographs, percussion, and cold thermal testing (EndoFrost; Roeko, Langenau, Germany). Over this period, a total of 59 patients were treated after the diagnosis of extensive primary or secondary deep caries in 64 teeth in which pulp exposure was anticipated because of caries extension on radiographic or clinical evaluation. Eventually, 64 permanent teeth were treated: 5 incisors, 17 premolars, and 42 molars; 38 were maxillary,
Direct Pulp Capping with MTA
1
Clinical Research and 26 were mandibular. The patient sample consisted of 32 females and 27 males with a mean age of 36.1 years (standard deviation [SD] = 15.1). All participants or legal guardians were asked to sign an informed consent form in which the treatment was briefly explained. The inclusion criteria were permanent teeth with caries, a positive cold test, the absence of spontaneous and lingering pain, the absence of percussion pain, and the absence of sinus tract or swelling. One operator (M.M.) completed all treatment procedures, with the exception of 2 definitive bonded restorations that were performed by another general practitioner at the same practice. All procedures were performed under a rubber dam and local anesthesia of 4% articaine with 1:100,000 epinephrine (ARTINIBSA; Laboratorios Inibsa SA, Barcelona, Spain). Caries excavation was performed under 6 to 16 magnification (DFV Vasconcellos MC-M1232; DFV, Rio de Janeiro, Brazil) using caries detector dye (Sable seek or Seek; Ultradent Products GmbH, Cologne, Germany) applied with a disposable brush tip (Black mini brush tip, Ultradent Products GmbH). High-speed round (801.314) diamond burs with medium grit 014, 016, or 018 (Komet Dental, Lemgo, Germany) on an air turbine with water and air spray coolant were used for enamel removal. Round steel (H1SE.204) slow-speed burs 014, 016, or 018 (Komet Dental) or LN burs 014, 016, or 018 (Dentsply Maillefer, Ballaigues, Switzerland) with water and air spray coolant and sharp hand excavators (EXCE2 and EXCE3; Hu-Friedy, Chicago, IL) were used for caries removal. Caries excavation continued even after pulpal exposures occurred and was complete when dentin offered resistance to hand excavation with a sharp excavator as per final inspection. In all cases in which pulp bleeding occurred, hemostasis was achieved with water from a 2-way syringe of the dental unit and occasionally pressure applied with dry cotton pellets. Subsequently, the surrounding dentin was gently air-dried with a 2-way syringe until all excess water had been removed. White MTA (ProRoot; Dentsply Tulsa Dental, Tulsa, OK) mixed according to the manufacturer’s instructions, 3:1 powder-to-liquid ratio, was applied in a thin layer of 1.5 mm over the exposure site and surrounding dentin with the aid of a double-ended medium 1.2-mm/1.6-mm ball burnisher (Henry Schein Inc, Melville, NY), leaving some circumferentially dentin available for bonding. Ten minutes after the direct capping procedure, a provisional restoration with zinc oxide/zinc sulfate–based cement (Coltosol F; Coltene/Whaledent, Altst€atten, Switzerland) was placed directly over the MTA. At the following appointment, 4 to 12 weeks later, if spontaneous pain complaints were reported, cold testing was negative, and/or
percussion resulted in a painful reaction, root canal treatment was performed. Otherwise, provisional restorations were removed with round steel (H1SE.204) slow-speed burs 014, 016, or 018 (Komet Dental) or LN burs 014, 016, or 018 (Dentsply Maillefer) with water and air spray coolant. MTA setting was confirmed and its color determined. A Palodent sectional matrix (Dentsply DeTrey GmbH, Konstanz, Germany) was adjusted, and a 35% phosphoric etchant solution (UltraEtch, Ultradent Products GmbH) for 30 seconds was applied on the enamel, dentin, and MTA surface and was rinsed and air-dried for 5 seconds. A light-curing adhesive agent (OptiBond Solo; KerrHawe Neos, Orange, CA) was applied with a microbrush in a brushing motion for 20 seconds, and excesses were blown out. The bonding agent was light cured (Bluephase G2 LED; Ivoclar Vivadent AG, Schaan, Liechtenstein) for 20 seconds, and all cavities were filled with composite (Tetric evo Ceram, Ivoclar Vivadent AG) in several layers and light cured for 40 seconds. Patients were recalled yearly for clinical tests and periapical radiographs. Success was defined as a positive cold test, no pain on percussion, and no widening of the periodontal ligament on the periapical radiograph. All radiographs were acquired using a dental radiograph unit (Philips Oralix 65; Philips, Eindhoven, The Netherlands) set at 65 kVp, 7.5 mA, and 0.2 seconds. A digital dental sensor (Visualix-1; Gendex Dental Systems, Milan, Italy) was used to capture all digital radiographs with a positioning holder using a perpendicular technique. The digital radiographs were visualized with imaging software (VixWin, Gendex Dental Systems) on a personal computer (ASUS Eee PC 1201 PN Netbook; ASUSTek Computer Inc, Taipei, Taiwan). One operator (M.M.) diagnosed recurrent caries through clinical and radiographic evaluation. When in doubt, the case was classified as having recurrent caries. The same operator classified discoloration subjectively as either discolored or not discolored. When in doubt, the case was classified as discolored. Data entry and analysis were performed with a statistical software package (SPSS 21.0; SPSS Inc, Chicago, IL). The Fisher exact test and the Kaplan-Meier method were used for analysis with a significance level of P < .05.
Results This sample consisted of 12 teeth with occlusal caries and 52 with proximal caries, of which 26 were primary caries and 38 secondary caries. On the first appointment, pulp bleeding during caries excavation occurred in 29 of the 64 teeth; 92.2% of the patients (59 teeth) returned for the second appointment. In 3 of 5 teeth that were lost to recall, no bleeding was detected during the first appointment, and in the
TABLE 1. Outcome of Direct Pulp Capping with Mineral Trioxide Aggregate According to Study Variables: Bleeding, Caries Location, Caries Treatment, and Age Studied variables (n = analyzed teeth) Success Pulp vitality without apical radiolucency, n (%) Failure Spontaneous pain, n (%) No pulp vitality with apical radiolucency, n (%) Difference between groups, % (95% CI) P value
Bleeding
Caries treatment
Caries location
Age
Present (n = 21)
Absent (n = 25)
Initial (n = 19)
Secondary (n = 27)
Occlusal (n = 7)
Proximal (n = 39)
.05
>.05
>.05
.05) (Fig. 1). The overall probability of pulp survival at 4 years was 87.3%.
Discussion The aim of this experimental clinical study was to evaluate the outcome of direct pulp capping using a specific 2-step protocol with MTA, and, thus, no control groups using either calcium hydroxide or indirect pulp capping were included. Incomplete caries removal was not considered as a treatment option for these patients because the quality of several studies that support this practice is low (12, 13). In an animal study, Cox et al (14) showed that a total of 192 dentin bridges formed against the fast-setting CH in 235 pulp-capped teeth, of which 41% were associated with recurring pulp inflammation or necrosis and were always associated with inflammatory cells and stained bacterial profiles. Dentin bridge formation after vital pulp therapy does not guarantee success. Histologic sections of healthy human or animal teeth capped with fast-setting CH-based cements showed the formation of tunnel defects in the calcified bridge (10, 14). Tunnel defects have also been observed in a carious human tooth capped with CH powder (15). In a multicenter randomized clinical trial, pulp capping of deep carious–exposed permanent teeth with fast setting CH reported a success rate of 31.8% after 1 year (8). Healthy teeth capped with MTA presented hard tissue barriers of steadily increasing length and thickness accompanied by healthy pulp tissue (10). Because of these advantages of MTA over CH and in order not to dilute the outcome of the result by dividing the limited available patients in 2 groups, no controls with CH or other materials were included. Studies on pulp capping of carious-exposed permanent teeth with MTA have reported high success rates, which ranged from 93%–98% (6, 16). The success rate of 91.3% in our study compares with the results of previous studies. This study has also some bias potential because the same operator performed treatments and follow-up procedures although a similar methodology was used in several vital pulp therapy studies (6, 17). The overall probability of pulp survival at 4
Direct Pulp Capping with MTA
3
Clinical Research
Figure 4. Treatment of the right first maxillary molar. (A) Initial radiograph with deep caries, (B) initial clinical photograph with extensive occlusomesial caries, (C) pulp exposure with bleeding from the mesiobuccal pulp horn, (D) MTA direct pulp capping over the mesiobuccal pulp horn and the surrounding dentin, (E) follow-up radiograph after 23 months, and (F) follow-up clinical photograph after 23 months.
years using the Kaplan-Meier survival probability test was 87.3%. This result was lower than the 94.87% reported in a previous study (6). This difference could be explained by several factors. In the former study, all teeth exhibited initial deep caries and no prior restorations, whereas in the current study, initial and secondary caries were treated. The age interval in the former study (7–45 years) was different than in the current study (8–68 years). 4
Marques et al.
Factors such as age, caries history, location, and blood clotting between the pulp and the capping material were already reported to have an influence on treatment outcome (1). Furthermore, a positive correlation was found between caries location and inflammatory pulp extension (18). In this study, caries location and pulp bleeding were explored as outcome predictors because of their potential importance for the success of pulp capping. JOE — Volume -, Number -, - 2015
Clinical Research In a clinical trial, a lower success rate of 56.2% was reported after direct pulp capping with MTA (19). However, no attempt was made to fully remove carious dentin as soon as pulpal bleeding was observed. The success of vital pulp therapy may depend on the complete removal of all disintegrated tissue (5). Controlling the infection is apparently a key point for clinical success of direct pulp capping (20). In our study, no case was excluded based on the amount of bleeding because this factor as an outcome predictor is controversial (21). In some cases, it was evident that MTA served to ‘‘soak up’’ oozing unclotted blood, and immediate staining of MTA was evident after 10 minutes (Fig. 2). Bleeding from the exposed pulp for longer than 5 and up to 10 minutes has previously been used as a threshold for reversible versus irreversible pulpitis classification (1, 6). Clinical trials verifying this threshold are lacking. In the current study, no attempt was made to rinse the pulp exposure with saline or a disinfectant, but instead water from the dental unit was used. Because the procedures were performed using nonsterile cooling water from the air turbine and the slow-speed contra-angle handpiece, it did not seem logical to use any specific substances for pulp disinfection. Furthermore, dentin surfaces treated by sodium hypochlorite may inhibit the differentiation of odontoblasts from dental pulp stem cells (20), and chlorhexidine may inhibit MTA setting (22). The tooth discoloration rate in this study was 13.6% with subjective assessment by 1 observer. It has been reported that vital pulp therapy with white MTA can result in discoloration (23). Pulp bleeding controlled with sodium hypochlorite may potentiate discoloration (24). Although in the current study the pulp was rinsed with water from a dental unit 2-way syringe, still some cases of discoloration were observed. Moreover, after removal of the provisional restoration, the surface color of MTA was changed from white to gray in all cases (Fig. 3). Bonded restorations and curing light promote an oxygen-free environment and may be responsible for the discoloration in our study (25). MTA usage in the esthetic zone should be done cautiously (23). It was recommended to temporarily place a moist cotton pellet in direct contact with MTA and leave it in until the follow-up appointment because moisture assists in the hydration of MTA from a colloidal gel that solidifies to a hard structure in approximately 3 to 4 hours (22). In the current study, no cotton pellet was used, and the MTA hardened in every case, suggesting that the moisture from the pulp was enough for the setting in vital pulp therapy procedures (26). This experimental study used a 2-appointment protocol for direct pulp capping with MTA (Fig. 4A–F). The best evidence available at the time of the study used this same protocol (6), and there is only limited evidence that a single-appointment protocol could give similar results (27). The hypothesis that young pulps with open apices and abundant blood supply will heal more often than the mature pulp with narrowed apices and poor blood supply (28) was only shown in the current study when 2 age groups (
