Γεώργιος Βαδιάκας, Επίκουρος Καθηγητής, Τμήμα Οδοντιατρικής, Σχολή Επιστημών Υγείας, ΕΚΠΑ
Σωτηρία Γκιζάνη, Αναπληρώτρια Καθηγήτρια, Τμήμα Οδοντιατρικής, Σχολή Επιστημών Υγείας, ΕΚΠΑ
Δημήτριος Εμμανουήλ, Επίκουρος Καθηγητής, Τμήμα Οδοντιατρικής, Σχολή Επιστημών Υγείας, ΕΚΠΑ
Introduction: Management of primary teeth with deep caries lesions close to the pulp has been extensively studied in the literature and mainly includes invasive techniques, such as pulpotomy or pulpectomy. Complexity of the clinical procedure, long chair sessions (occasionally more than one), substantial tooth loss and increased financial cost are among the disadvantages of these techniques. In recent years, less invasive pulp treatment modalities have been suggested, to preserve healthy tooth substance. While direct pulp capping is a well accepted and established technique for permanent teeth, the same doesn't hold true for primary teeth. The technique is still not recommended by prominent scientific societies on the basis of inadequate clinical research findings. Among the materials already used for direct pulp capping in permanent teeth, Ca(OH)2 has long been the material of choice. Nevertheless, the use of Ca(OH)2 for direct pulp capping in primary molars is controversial because of its low success rates, based on histopathological data. MTA has been clinically studied and found effective for direct pulp capping in deciduous teeth. However, its high cost limits its widespread use in clinical practice. Pure Portland cement® Med-PZ is a new material, which was introduced in clinical dental practice in 2012 and has similar to MTA properties. Few clinical studies have tested this material for pulp treatment of primary teeth. Biodentine ™ is a tricalcium silicate (Ca3SiO5) based in organic nonmetallic material. The literature concerning the use of this material in primary teeth is also limited. According to a meta-analysis of 2017, there is limited and conflicting evidence in the literature as regards to the use of direct pulp capping in primary teeth.
Aim: Τo estimate and compare the success rates of the direct pulp capping treatment modality in primary molars with cariously exposed pulps, using three different direct pulp capping materials, Ca(OH)2, Pure Portland cement® Med-PZ and Biodentine™.
Materials and Methods: The study sample consisted of patients that presented in the Postgraduate clinic of Paediatric Dentistry at the National and Kapodistrian University of Athens, seeking for dental treatment. The patients were included in the study if they met the following eligibility criteria: had an uneventful medical history and presence of first or second deciduous molars with deep active caries lesions, resulting to pulp exposure after caries removal. All participating teeth were free of signs and symptoms indicative of irreversible pulp inflammation. More specifically, for participation into the study sample, the following clinical criteria were fullfilled: no history of pain, healthy periodontal tissues in the absence of fistula or swelling, lack of mobility and percussion sensitivity, while the teeth had to be restorable after caries removal, with a vital pulp and an exposure that did not exceed 1-2 mm. Control of hemorrhage without the use of hemostatic agents was accomplished within 2-3 minutes. Radiographically, no periapical or furcal radiolucency and no internal or external resorption and calcification were present. Lamina dura had to be continuous and intact and the remaining root length at least half of the original. The teeth were divided into 3 groups, one for each pulp capping material: GrA: Ca(OH)2, GrB: Pure Portland cement® and GrC: Biodentine™. All direct pulp capping procedures were performed by one paediatric dentist. In all three groups, following clinical and radiographic examination (periapical radiograph), the teeth were anaesthetized locally with articaine 4% with epinephrine 1/200.000 and isolated by rubber dam. All enamel and dentine caries were removed. Teeth with an exposure less than 2 mm, surrounded by sound dentine were candidates for direct pulp capping. If the pulp size exposure was greater than 2 mm, or if the bleeding was not controlled with a sterile cotton pellet within 2-3 minutes, the tooth was excluded from the study and a pulpotomy was performed. Hemostasis was achieved with 0.5% NaOCl washes followed by application of dry sterile cotton pellets. In group Α, Ca(OH)2 (Dycal, Dentsply, Milford, DE, USA) and in group B, Pure Portland cement® Med-PZ was placed. A resin modified glass ionomer cement (Vitrebond, 3 M ESPE, St Paul, MN, USA) was placed on top of the pulp capping material and the tooth was restored with composite resin. In group C, Biodentine™ was placed on the exposed pulp. After setting of the material the tooth was restored with composite resin. In all three groups, a periapical radiograph was taken, immediately post-treatment. Patients were re-examined at 3, 6 and 12 months after treatment and every 6 months, thereafter. The recall examination included clinical and radiographic evaluation by two blinded and previously trained and calibrated pediatric dentists, regarding the clinical and diagnostic criteria used (intra-examiner reproducibility kappa = 0.83 and 0.92; inter-examiner reproducibility kappa = 0.96). All teeth were assessed for presence of signs or symptoms of pain, sensitivity to percussion or palpation, fistula, swelling, internal or external resorption, periapical or furcal radiolucency, which are indicative of pulp necrosis.
Statistical analysis: Descriptive statistics with cross tabulations were performed. Chi-squared and Fisher’s exact tests were applied as appropriate. Kaplan - Meier survival curves for each pulp capping material, type of tooth, age and gender were calculated. A univariable and multivariable random effects Cox regression model, was built based on pre-defined covariates, such as pulp capping material, tooth type, dental arch, gender and age. The proportional hazards assumptions were checked through Nelson Aalen plot for log cumulative hazard by type of direct pulp capping material. A two-sided p-value of 0.05 was used to determine statistical significance for all analyses, along with 95% CIs. All analyses were performed using Stata v.14.1.
Results: A total of 66 patients (25 girls, 41 boys) with a mean age of 7.2 years (SD: 1.7, range: 4.1-11.2) participated in the study. The mean follow-up time was 1.1 years (range: 0.19-2.48 years). The total number of primary molars included in the study was 79, which were assigned to 3 groups, GrA (n=27), GrB (29) and GrC (n=23), 39 of them (49%) were first primary molars, 40 (51%) were second, 22 (28%) lower and 57 (72%) upper, 36 (46%) left and 43 (54%) right. Class II composite resin restorations were performed in 75 (95%) teeth, while 4 (5%) teeth were restored with Class I. The overall failure for the direct pulp capping treatment regardless of the material used was 16%. The distribution of tooth failures by group was: Group A, 5 teeth, group B, 5 teeth and group C, 3 teeth. No statistically significant difference between failure and type of pulp capping material was found (fisher's exact test, p=0.93) For more than half of the teeth that failed, the event of failure occured within the first 6 months, post-treatment. In the multivariable model after adjusting for sex, age, tooth type and dental arch, Portland Cement and Biodentine exhibited a 59% and 46% lower hazard for tooth failure compared to Dycal respectively (Portland Cement vs Dycal: HR=0.41; 95% CIs: 0.03, 5.48; p=0.50; Biodentine vs Dycal: HR=0.54; 95% CIs: 0.02, 15.25; p=0.72). None was either statistically or clinically significant.
Conclusions: Direct pulp capping in primary molars with a cariously exposed pulp exhibited an overall success rate of 84% based on clinical and/or radiographic diagnostic criteria, after a mean follow-up period of 12 months. However, no significant difference in failure rate among the different pulp capping materials used was found. Longer follow-up periods are needed to further assess the long-term clinical and radiographic effectiveness of direct pulp capping after application of the materials studied.