Comparative analysis of the success rate of direct and indirect pulp capping procedures - A retrospective analysis

Treatment options of pulp exposure involve either extraction or root canal therapy, as latter involves multiple appointments and considerable expense. An alternate procedure is pulp capping, which is divided into two types- direct, indirect pulp capping. The aim of this study was to assess and compare the success rate of direct and indirect pulp capping procedures based on postoperative pain and patient's visit after pulp capping procedure. As it was a retrospective analysis, data collected from hospital, Chennai, and it consisted of a total of 439 cases evaluated based on the type of pulp capping done. Inclusion criteria consisted of Patients aged 18 – 50 years who received direct, indirect pulp capping procedures. Patients who received deep caries management. Patients who have obvious carious lesions noted clinically, radio graphically and received either complete/ partial caries removal followed by placement of cavity liner. The collected data was imported to excel sheet, analyzed using SPSS software. In this study of 261 patients (99 are females, 162 are males with a mean age of 18-40) were included. It was observed that there was not a significant difference among the groups. Indirect pulp capping has a higher success rate over Direct pulp capping with a p-value greater than 0.05. Within the limitations of this study, it can be concluded that the indirect pulp capping has a higher success rate over the direct pulp capping procedures, although it's not statistically significant.


INTRODUCTION
Preserving the natural tooth structure seems to be vital for many reasons beyond cosmetic purpose. The consequences of pulp exposure occur as a result of caries, trauma, or misadventure occurs during tooth preparation, and end results occur with the pain and infection (Oen et al., 2007). Treatment options for pulp exposure involve either extraction or root canal therapy (Mertz-Fairhurst et al., 1998). An alternate procedure is pulp capping which is divided into two types-direct, indirect pulp capping (Maltz et al., 2007). The success of pulp vitality procedures depends upon many factors (Stanley, 1998). Different types of restorations used in pulp capping procedures affect outcome results. Calcium hydroxide has a higher success rate of up to 10 years (Bogen et al., 2008).
Dental pulp has a natural potential for tissue repair, which leads to the formation of reparative dentin. Direct pulp capping consists of the application of bio compatible materials in the exposure tissue to seal the communication as a barrier; It protects the pulp complex and vitality (Bleicher, 2014).
The bio compatible materials used for pulp vitality procedures are calcium hydroxide, MTA (Mineral trioxide aggregate). (Poggio et al., 2014a) The MTA cement is bio active, bio compatible, antibacterial and has good stability, sealing ability. Some disadvantages are long setting time, poor handling properties, high cost, the potential for discoloration Salehi et al., 2016).
The aim of this study was to assess and compare the success rate of direct and indirect pulp capping procedures based on postoperative pain and patient's visit after pulp capping procedure.

Study Design
A single centered retrospective study.

Ethical Approval
Approval for the project was obtained from the Institutional Review Board of Saveetha Institute of Medical and Technical Sciences, Chennai, India on Date 18/04/2020. Chart 1: Bar chart showing an association between age and pulp capping.

Inclusion criteria
Patients of age 18 -50 years who received direct, indirect pulp capping procedures, patients who received deep caries management, patients who have obvious carious lesions noted clinically, radio graphically and received either complete/ partial caries removal followed by placement of cavity liner were all included.

Exclusion criteria
Patients who have not undergone deep caries management, and patients who received endodontic therapy, patients who received mild class I cavity restorations were excluded from the study.

Data Extraction
Data were evaluated using 439 patient's records from June 2019 to March 2020. Data collection was accomplished using standardized software. It consists of the patient's demographic information and procedural data. The inal data was exported to excel and analyzed. The case selection and data extraction is shown in Figure 1.
Chart 2: Bar chart showing an association between gender and pulp capping.

Sample size
A total of 439 patients charts, identifying pulp capping procedures completed over a period of one year. Among that, 261 cases met the eligibility criteria. The sampling method used was the data evaluated, collected from the patient record at Saveetha Dental College, Chennai. Among the total cases, 97 patients underwent direct pulp capping procedures, and 164 patients underwent indirect pulp capping procedures.
Chart 3: Graph showing the correlation between age and the count of pulp capping.

Groups
The pulp capping procedures done were The primary clinical outcome of this procedure was to evaluate the success rate. The success rate is assessed based on Patients visit the clinics because of pain after pulp capping procedure and also the maintenance of pulp vitality. All patients were followed up and received a permanent restoration within the period of one month.

Clinical Protocol
The clinical protocol for the patients undergoing pulp capping procedure is to assess the pulp status by pulp vitality tests, clinical and radio graphic indings. After performing the diagnostic procedures, the caries was removed, and a radio graph was taken to con irm the status of pulpal involvement after caries removal and then based on clinical and radio graphic indings, the decision of whether direct/indirect pulp capping was taken. Calcium hydroxide was used in both direct and indirect pulp capping cases predominantly followed by cavity liner, temporary restoration.

Study Outcome
The success rate is assessed based on Patients visit because of pain after pulp capping procedure. Since the patient's next visit for patients who received temporary restorations is to be replaced with permanent restorations, many patients reported pain after pulp capping procedure.

Statistical Analysis
Chi-square test was done to assess these parameters. The outcome data was represented in the form of tables and graphs. The four tables represent the frequency of pulp capping procedure done based on the age, gender, teeth number of the patient. The graphs are representing the correlation between these parameters-Correlation of age and type of pulp capping, gender and type of pulp capping, teeth number and type of pulp capping.

RESULTS AND DISCUSSION
In this study comparing direct, indirect pulp capping procedures, indirect pulp capping procedures (group B) has a higher success rate than direct pulp capping procedures (group A). In this study comprising 261 cases, 32 patients did not report back for a permanent restoration. Among 97 direct pulp capping cases, 79 patients reported for permanent restoration, and 54 patients reported pain and the endodontic procedure was initiated in 31 patients and others kept under observation. Among 164 indirect pulp capping procedures, 132 patients reported back, and 39 patients complaints of pain and the endodontic procedure were initiated in 19  Chart 3 shows that the X-axis denotes the teeth and Y-axis denotes the count of pulp capping. Depending on the frequency of pulp capping procedure based on the teeth of the patient, anterior accounted for 13.6% overall cases, and posteriors accounted for 86.4% overall cases. Based on teeth and the type of pulp capping used maximum cases accounted for indirect pulp capping. There is no signi icant difference in between the groups in Chi-Square test-1.485, the p-value is 0.74>0.05 Table 3. The success of pulp vitality procedures is in luenced by many factors ranging from the age of the patient to the type of restorative material used (Song et al., 2017;Poggio et al., 2014b).
Among 97 direct pulp capping cases, 79 patients reported for permanent restoration, and 54 patients  (Chang et al., 2014b). Horsted et al.,2003 analyzed pulp vitality success rate based on dentin adhesion. The presence of intense in lammatory response for teeth treated showed a variation of 0-100% (mean of 41.6%) compared to the variation of 0-20% (mean of 7.4%) treated with calcium hydroxide (Smith et al., 2012;Larmas and Sándor, 2014). In teeth treated with calcium hydroxide, expression of three collagen, ibronectin was increased over a period of time (Atari et al., 2012;Chang et al., 2014a).
The true gold standard of pulp status is histological analysis. Unfortunately, the true state of pulp health/ pathology cannot be determined using clinical/ radio graphic appearance (Khademi and Akhlaghi, 2015;Min et al., 2008). A study analyzed the series of changes occurring to carious lesions after partial removal for a time duration of 4-12 months, such as reduction of microbial load, color change and consistency of carious lesion (Ferracane et al., 2010;de Lourdes R. Accorinte et al., 2008). The type of liner is less important to success than the placement of the well-sealed restoration. Substantial evidence showing that complete removal of caries is not needed for success provided the restoration is well sealed (Sawicki et al., 2008).
Caries preservation to a pulp will result in bacterial invasion of pulp, resulting in pulpal in lammation. For attaining clinical success, placing the wellsealed permanent illing is important (Shahravan et al., 2011). Another factor which is having an effect on the success of direct pulp capping is controlling pulpal bleeding. (Accorinte et al., 2009). The materials used in direct pulp capping procedure were zinc oxide eugenol, glass ionomer cement, adhesive cement and these cement have good aesthetic properties (Jose et al., 2020;Ravinthar and Jayalakshmi, 2018). The advantages of glass ionomer cement include luoride release and remineralization of carious lesions to some extent Nasim and Nandakumar, 2018;Rajendran et al., 2019). (Manohar and Sharma, 2018;Noor and Pradeep, 2016;Ramamoorthi et al., 2015) The above factors should be considered in pulp capping procedures. It is similar to many factors that in luence the endodontic therapy such as proper disinfection, shaping, placement of intracanal medicament. (Ramanathan and Solete, 2015;Siddique et al., 2019;Teja and Ramesh, 2019) Similarly, many factors in luence the vital status of pulp in case of In lammation, traumatic injury, calciied canal. (Kumar and Antony, 2018;R and Ms, 2019) The pulpal diagnosis should be made properly with advanced armamentarium (Janani et al., 2020;Ramesh et al., 2018).
The chances of tooth survival after pulp capping were found to be well provided if the patient doesn't have symptoms (Nair et al., 2008). Yet, misconceptions are noted in pulp vitality procedures starting from proper diagnosis to follow up (Ritter, 2007). In this study, the overall consensus it agreed with previous literature showing that success rate is excellent if properly sealed irrespective of residual caries noted in teeth underwent pulp capping procedures.

Overall Consensus
In agreement with the indings of the study.

Study Limitation
The limitations of this study were it involved relatively a smaller number of population. The success rate evaluated based on one parameter-postoperative pain and not based on restorative material used for pulp capping procedure.

Future Scope
The future scope can be focused on a relatively larger number of populations to be assessed for attaining a clear protocol regarding success rate. The restorative material used in direct, indirect pulp capping procedures to be assessed based on their bio compatible nature, sealing ability, adhesion to teeth.

Declaration of Patient Consent
The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

CONCLUSIONS
Within the limitations of this study, it can be concluded that the indirect pulp capping has a higher success rate over the direct pulp capping procedures, although it's not statistically signi icant.

Funding Support
The authors declare that they have no funding support for this study.