Interim and temporary restoration of teeth during endodontic treatment

Guidelines for non-surgical root canal treatment

Guidelines were developed by the Australian Society of Endodontology Inc. with the intent to describe relevant aspects of contemporary evidence-based root canal treatment. The document aims to support clinicians by describing a Standard of Practice in the Australian context. The presented guidelines refer to Competence criteria and Quality standards for the main steps in root canal treatment. While the intent is not to replace individual clinical decision-making, it is envisaged that these periodically reviewable guidelines may help to improve clinical outcomes.

Overview of Interim and Temporary Restorations of Teeth During Endodontic Treatment

Root canal treatment of vital, non-infected teeth can often be completed in a single visit, negating the necessity for dressing and provisionalization. Conversely, cases involving infected canals typically demand multiple visits, during which antibacterial medicaments are applied, making effective provisionalization crucial for varying durations. The key components of a successful root canal treatment include adequate canal shape to promote efficient obturation, thorough chemical and mechanical debridement, and complete removal of pulp tissue remnants and bacteria. The primary cause of pain following the initiation of endodontic treatments is often attributed to inadequate debridement or incomplete removal of the pulp tissue, closely followed by insufficient temporary restorations. This review aims to comprehensively overview provisionalization materials used during and immediately after endodontic procedures.

Biological considerations of dental materials as orifice barriers for restoring root-filled teeth

There is ample published literature regarding the technical aspects of restoring root-filled teeth, but little concerning the biological impacts, consequences, and criteria for the selection of direct restorative materials following endodontic treatment. The provision of an effective coronal seal in addition to a sound root filling is known to be important in the prevention of root canal infection. This review seeks to explore the evidence concerning the selection of dental materials in the restoration of root-filled teeth, specifically with a close examination of the properties of commonly used materials as orifice barriers. © 2023 Australian Dental Association.

Microleakage Evaluation of Temporary Restorations Used in Endodontic Treatment-An Ex Vivo Study

(1) Background: Coronal microleakage can lead to endodontic treatment failure. This study aimed to compare the sealing ability of different temporary restorative materials used during endodontic treatment. (2) Methods: Eighty sheep incisors were collected, uniformized in length, and access cavities were performed, except for in the negative control group, where the teeth were left intact. The teeth were divided into six different groups. In the positive control group, the access cavity was made and left empty. In the experimental groups, access cavities were restored with three different temporary materials (IRM^®, Ketac™ Silver, and Cavit™) and with a definitive restorative material (Filtek Supreme™). The teeth were submitted to thermocycling, and two and four weeks later, they were infiltrated with ^99mTcNaO₄, and nuclear medicine imaging was performed. (3) Results: Filtek Supreme™ obtained the lowest infiltration values. Regarding the temporary materials, at two weeks, Ketac™ Silver presented the lowest infiltration, followed by IRM^®, whereas Cavit™ presented the highest infiltration. At four weeks, Ketac™ Silver remained with the lowest values, whereas Cavit™ decreased the infiltration, comparable to IRM^®. (4) Conclusion: Regarding temporary materials, Ketac™ Silver had the lowest infiltration at 2 and 4 weeks, whereas the highest infiltration was found in the Cavit™ group at two weeks and in the IRM^® group at 4 weeks.

Restorative and Endodontic Management of a Mandibular Canine With Two Roots and Two Canals: A Case Report

The existence of a permanent mandibular canine with two roots and two canals is rare. This case report presents restorative and endodontic management of a mandibular canine with two roots and two canals of a 32-year-old Saudi woman with multiple periradicular lesions of mandibular anterior teeth. Cone beam computed tomography (CBCT) was used for accurate diagnosis of the root canal morphology. CBCT helped to accomplish the restorative and endodontic treatment in a conservative approach.

Undergraduate Endodontic Training and Its Relation to Contemporary Practice: Multicenter Cross-Sectional Study in Saudi Arabia

Materials and Methods

An online questionnaire was developed and emailed to all dental schools in Saudi Arabia. This questionnaire was answered by the endodontic undergraduate program director. The data collected were analysed using descriptive statistics.

Results

The response rate was 96.15%, which means twenty-five out of twenty-six dental schools participated in the study. The majority of the academic supervisors was endodontists (92%). The use of magnification and ultrasonic tips was not required by 84% and 76% of the dental schools, respectively. The main endodontic treatment techniques were the step-back technique and gates glidden for cleaning and shaping (76%) and cold lateral compaction for obturation (92%).

Conclusions

The dental students were supervised by endodontic specialists and trained to use traditional endodontic methods. Encouraging dental educators to train students to use modern technology and equipment would probably improve their graduate clinical skills and performance.

Effect of Different Indirect Composite Onlay and Core Materials on Fracture Resistance of Endodontically Treated Maxillary Premolars

PURPOSE

To compare and evaluate the effects of different indirect composite onlay and/or core buildup materials on the fracture resistance and fracture mode of restored endodontically treated premolars.

METHODS

Two conventional handmade indirect composite resins (SR Nexco (NC) and Ceramage (CM)) and two core buildup materials, dual-cure composite resin (MultiCore Flow (MC)), and short fiber-reinforced composite resin (EverX Posterior (EXP)), were selected. Sixty maxillary premolars were randomly divided into six groups (n=10). Group 1 included intact teeth (INT; negative control). Mesio-occluso-distal cavity preparation and endodontic treatment was performed on the remaining premolars. Group 2 was restored with polymer-reinforced zinc oxide eugenol intermediate restorative material (IRM; positive control), whereas the experimental groups (groups 3-6) were restored with core buildup material and indirect composite onlay (MC_NC, MC_CM, EXP_NC, and EXP_CM). The specimens received compressive loading using a universal testing machine, at 45° to the long axis with a crosshead speed of 0.5 mm/min until fracture. Fracture modes were visually analyzed. Fracture resistance was measured and statistically analyzed using two-way and one-way ANOVA (α=0.05).

RESULTS

Only the type of indirect composite onlay affected the fracture resistance of the experimental groups (P=0.009). The MC_CM group showed the highest fracture resistance, which was significantly higher than that of the MC_NC group (P=0.031). No statistically significant differences were found between the INT group and other experimental groups(P>0.05). All groups had a greater incidence of restorable than unrestorable failures.

CONCLUSION

The type of indirect composite onlay affected the fracture resistance of restored endodontically treated maxillary premolars.

Symptomatic Apical Periodontitis of the Mandibular First Molar with the Accessory Canal in the Furcation Area Mimicking Furcation Perforation

Apical periodontitis frequently presents as a chronic disease. To arrive at a true diagnosis, in addition to the clinical examination, it is mandatory to undertake radiographic examinations and evaluate the clinical presentation. Knowledge of the root canal morphology is a prerequisite for effective nonsurgical endodontic treatment. The internal morphological features of the pulp chamber are variable and complex. This case report describes the treatment and outcome of symptomatic apical periodontitis of a mandibular first molar with the accessory (chamber) canal. The applied treatment fully contributed to the periapical lesion regression as shown in the four-year recall periapical radiography.

Comparative Evaluation of Cotton PTFE Tape and Foam Pellets as Endodontic Spacer in Primary Teeth: An In Vivo Study

Aim and objective

This study was conducted to microbiologically evaluate cotton, PTFE tape, and foam pellets as endodontic spacer in primary teeth.

Materials and methods

Thirty primary second molars indicated for pulpectomy were included in this study. Followed by the completion of pulpectomy in each teeth cotton, PTFE tape, and foam pellets were placed as endodontic spacers randomly in 10 teeth each. The samples were collected from the pulp chamber at baseline and after 7 days to evaluate for microbial contamination of the same. The data obtained was tabulated and subjected to appropriate statistical analysis.

Results

There was a statistically significant increase in the colony forming unit after 7 days in cotton and foam pellet group. But PTFE tape group showed very minimal contamination of the pulp chamber after 7 days.

Conclusion

Within the limitations of this study, it can be concluded that PTFE tape found to be the best alternative to cotton as an endodontic spacer.

Clinical significance

In case of multiple visit pulpectomy procedure, the state of sterility must be maintained in between the appointments until a definitive coronal restoration is placed following root-canal obturation. So it is mandatory to place an endodontic spacer under a provisional restoration to maintain the patency of the root canals and prevention of the microbial growth. The PTFE tape is inorganic, nonfibrous material which can be tightly packed without any voids under the provisional restoration. So PTFE tape is the best material to maintain the root canal patency and to provide a sterile environment by preventing the microbial growth under the provisional restoration as an endodontic spacer material in between the appointments.

How to cite this article

Somani R, Arya MV, Singh DJ, et al. Comparative Evaluation of Cotton PTFE Tape and Foam Pellets as Endodontic Spacer in Primary Teeth: An In Vivo Study. Int J Clin Pediatr Dent 2022;15(1):74-78.

Comparative Analysis of Root Canal Dentin Removal Capacity of Two NiTi Endodontic Reciprocating Systems for the Root Canal Treatment of Primary Molar Teeth. An In Vitro Study

The objective of the present study was to evaluate and compare the dentin removal capacity of Endogal Kids and Reciproc Blue NiTi alloy endodontic reciprocating systems for root canal treatments in primary second molar teeth via a micro-computed tomography (micro-CT) scan. Materials and Methods: Sixty root canal systems in fifteen primary second molar teeth were chosen and classified into one of the following study groups: A: EK3 Endogal Kids (n = 30) (EDG) and B. R25 Reciproc Blue (n = 30) (RB). Preoperative and postoperative micro-CT scans were uploaded into image processing software to analyze the changes in the volume of root canal dentin using a mathematical algorithm that enabled progressive differentiation between neighboring pixels after defining and segmenting the root canal systems in both micro-CT scans. Volumetric variations in the root canal system and the root canal third were calculated using a t-test for independent samples or a nonparametric Mann–Whitney–Wilcoxon test. Results: Statistically significant differences (p = 0.0066) in dentin removal capacity were found between the EDG (2.89 ± 1.26 mm³) and RB (1.22 ± 0.58 mm³) study groups for the coronal root canal third; however, no statistically significant differences were found for the middle (p = 0.4864) and apical (p = 0.6276) root canal thirds. Conclusions: Endogal and Reciproc Blue NiTi endodontic reciprocating systems showed similar capacity for the removal of root canal dentin, except for the coronal root canal third, in which the Reciproc Blue NiTi endodontic reciprocating system preserved more root canal dentin tissue.

Present status and future directions - managing endodontic emergencies

Endodontic emergencies are common in both general dental practices and specialist Endodontic practices. The aim of this review is to provide an overview of endodontic emergencies. Endodontic emergencies can be a result of many different conditions of the pulp, root canal and periradicular tissues. They may occur before endodontic treatment has been started, between appointments when treatment is being performed over multiple visits, or after endodontic treatment has been completed. In the latter situation, the emergency may be very soon after the treatment or it may occur many years later, in which case it is usually a new disease process as a result of the root canal system becoming infected. An emergency can be a stressful situation for both the patient and the dentist (or endodontist) as it is usually an unexpected event. It is incumbent on dental professionals to provide timely assistance to patients who have an emergency, and it is also important to allow sufficient time to manage the situation comprehensively. Management of endodontic emergencies should follow the principles of the 3D's - Diagnosis, Definitive dental treatment and Drugs - and in that sequence. An accurate diagnosis, the first "D", is essential so the appropriate treatment can be provided. Diagnosis requires a thorough understanding of the various conditions that can cause the emergency and this can be helped by having a comprehensive classification of the various conditions. The diagnosis should also direct the clinician to the appropriate definitive dental treatment, the second "D". Root canal treatment will not always be required as some cases can be managed conservatively. Other cases may require root canal re-treatment. The specific details of how the treatment is done can also vary, according to the diagnosis. The final "D" is Drugs - the use of drugs should also be dependent on the diagnosis and the dental treatment. Drugs should only be an adjunct following the treatment. The clinician must also differentiate between inflammation and infection in order to provide the appropriate treatment and to prescribe the appropriate medication for effective pain relief and resolution of other symptoms or signs such as swelling.

Common Temporization Techniques Practiced in Saudi Arabia and Stability of Temporary Restoration

Introduction

Coronal leakage is detrimental to the long-term success of root canal treatment (RCT). While much emphasis is being placed on the quality of the final restoration, little attention is given to the temporary restoration placed in between root canal treatment appointments. The aim of this study was to survey temporization techniques practiced in Saudi Arabia and the frequency of observing temporary material breakdown or complete loss.

Materials and Methods

An online questionnaire was distributed among general dentists, dental specialists, and clinical trainees in undergraduate and postgraduate dental programs. The sample size was estimated at 370 participants. Data were analyzed using descriptive statistics and chi-square tests.

Results

The total number of participants who met the inclusion criteria was 525. The majority of them (94.6%) were practicing two-visit RCT. The most common temporization materials were Cavit (50.3%) followed by glass ionomer cement (32%). The majority (72.6%) of participants claimed they allow a thickness of 2-3 mm for temporary restorations. Many participants (60.4%) used a spacer material during temporization, and the cotton pellet was the most common spacer material. Temporary restoration breakdown or complete loss was a common observation. Although the duration between the two RCT visits was 2 weeks or less for 83.6% of participants, only 19.6% of participants claimed that they rarely observed temporization breakdown.

Conclusion

Two-visit RCT is commonly practiced in Saudi Arabia, and endodontists performed significantly more single-visit procedures. Temporization practices may lack uniformity; however, clinicians were more likely to use calcium sulfate-derived material for two weeks or less. They allow for 2-3 mm thickness restoration and use a cotton pellet as a spacer. According to their clinical observation, temporary material breakdown or complete loss was frequent. This mandates further attention in research and education.

Microbial Contamination Comparison Between Cotton Pellet and Polytetrafluoroethylene Tape Endodontic Spacers: A Systematic Review

This systematic review compares polytetrafluoroethylene tape and cotton pellet when used as endodontic spacers underneath provisional restorations. The review followed the PRISMA guidelines and was registered in the PROSPERO database (CRD42020176555). Studies that compared the microbial contamination between polytetrafluoroethylene tape and cotton pellet, when used as spacers, were included. Literature searches of Pubmed, Embase, EBSCOHost Dentistry & Oral Sciences Source, Scopus, and Open Grey databases were conducted from their inception until May 2020 for studies in English or other Latin script languages. Hand searching of reference lists was performed. Three laboratory and three clinical studies were included. The risk of bias of the component studies varied widely. Results from the laboratory studies showed higher bacterial counts for cotton pellets. Results from the clinical studies showed that polytetrafluoroethylene tape was associated with a significantly lower incidence of microbial contamination. Findings were consistent throughout the studies, though the evidence available is scarce and heterogeneous. Polytetrafluoroethylene tape was associated with less microbial contamination when compared with cotton pellets as endodontic spacers and therefore appears to be a more suitable material for the purpose.

Assessment of bacterial and dye penetration through post/crown interim restorations while under simulated masticatory load

The aim was to compare two temporary cements to determine which resisted bacterial and dye penetration under temporary posts/cores/crowns subjected to simulated masticatory function. Forty-six single canal human tooth roots were prepared for posts/crowns. A cotton pellet and Cavit were placed in each post space. Temporary posts/cores/crowns were cemented with Intermediate Restorative Material (IRM) (n = 23) or Tempocem (n = 23). Specimens were sterilised, then immersed in a mixture of Streptococcus gordonii and India ink, and subjected to 4 weeks simulated mastication. Dye penetration was assessed by visually inspecting the cotton pellets. Bacterial penetration was determined by placing the pellets into sterile broth and by plating them onto agar plates to confirm S. gordonii growth. There was no statistically significant difference between the cements and the dependent variables of bacterial and dye penetration. Hence, both cements are good options to cement temporary posts/cores/crowns during endodontic treatment of anterior teeth.

Coronal Bacterial Penetration after 7 days in class II endodontic access cavities restored with two temporary restorations: A Randomised Clinical Trial

The aim of this in vivo randomised clinical trial was to assess coronal bacterial penetration after placement of Cavit G and IRM temporary restorations in Class II endodontic access cavities. After completion of endodontic treatment, placement of an orifice seal and disinfection of the operating field, sterile cotton pellets were placed in the pulp chamber and the cavities were restored with Cavit G or IRM. After 7 days, coronal and proximal restoration thickness was measured by digital radiographs. Cotton pellet was evaluated by culture methods and polymerase chain reaction assay and bacterial species identified. Bacterial growth was observed in 5 of the 27 (18%) Cavit G samples and in 11 of the 27 (40%) IRM samples which was not significant. Coronal restoration thickness of 4-5 mm and proximal restoration thickness of more than 2.15 mm for Cavit G and 2.35 mm for IRM are recommended to prevent bacterial penetration over 7 days. Adequate restoration thickness is critical to prevent bacterial penetration.

Cytocompatibility of 3D printed dental materials for temporary restorations on fibroblasts

Background

Three-dimensional (3D) printing is widely used in the fabrication of dental prostheses; however, the influence of dental materials used for 3D printing on temporary restoration of fibroblasts in tissues is unclear. Thus, the influence of different dental materials on fibroblasts were investigated.

Methods

Digital light processing (DLP) type 3D printing was used. Specimens in the control group were fabricated by mixing liquid and powder self-curing resin restoration materials. The temporary resin materials used were Model, Castable, Clear-SG, Tray, and Temporary, and the self-curing resin materials used were Lang dental, Alike, Milky blue, TOKVSO CUREFAST, and UniFast III. Fibroblast cells were cultured on each specimen and subsequently post-treated for analysis. Morphology of the adhered cells were observed using a confocal laser scanning microscope (CLSM) and a scanning electron microscope (SEM).

Results

CLSM and SEM cell imaging revealed that the 3D printed material group presented better cell adhesion with well-distributed filopodia compared to that in the conventional resin material group. Cell proliferation was significantly higher in the 3D printing materials.

Conclusion

Superior cytocompatibility of the specimens fabricated through 3D printing and polishing process was demonstrated with the proof of better cell adhesion and higher cell proliferation.

An assessment of endodontic treatment completion rate in a University-based student clinic and the factors associated with incomplete treatment

Incomplete endodontic treatment is potentially a public health issue. The aim of this retrospective study was to evaluate the endodontic treatment completion rate at a University student clinic and to identify the factors associated with completion rates. The records of all patients who commenced an endodontic treatment (code 415) from January 2015 to December 2015 were extracted. A total of 783 records were available for analysis of which 86% received complete endodontic treatment. Maxillary first molars were significantly associated with incomplete endodontic treatment (IET). Patients requiring an additional visit (code 455) were 1.5 times more likely to have an IET. The endodontic treatment completion rate at the School of Dentistry at the University of Queensland is higher than those reported in other international university-based student clinics. Focus group surveys of students and supervisors are required to identify the reasons for higher IET with maxillary first molars and code 455.

Pre-endodontic Post and Core Technique for Endodontic and Prosthodontic Treatment

INTRODUCTION

Displacement of provisional fixed prostheses may result in undesirable and embarrassing outcomes in dental treatments, especially in endodontic treatment. Development of certain counter measures has been necessary to avoid such discomforts.

AIM

The aim of this report was to propose a pre-endodontic post and core technique to achieve smooth progress of the treatment.

MATERIALS AND METHODS

The patient was a 59-year-old male diagnosed with an infraocclusion caused by wear of his teeth. He received full mouth provisional fixed restorations for a complete oral rehabilitation. Displacement and fracture of the restorations frequently occurred during the observation period for the function of the restorations. Therefore, the pre-endodontic post and core technique was applied to the abutment teeth before their endodontic treatments were started. The technique consisted of three steps as follows: Step 1: Caries removal and dowel preparation were performed for the abutment teeth having apical periodontitis. Composite cores were indirectly fabricated, which had access holes for endodontic treatment. Step 2: The cores were bonded to the teeth. In endodontic treatment, rubber dam appliances were easily placed owing to the core, and proper tooth isolation was accomplished. Step 3: Fiberposts were bonded to the dowel holes through the access holes after the root canal filling. During endodontic treatment, displacement and/or fracture of the provisional restorations did not occur.

CONCLUSION

The pre-endodontic post and core technique was effective in obtaining improved retention of provisional restoration, appropriate isolation for endodontic treatment, and sufficient retention of the post and core.

CLINICAL SIGNIFICANCE

The pre-endodontic post and core technique is useful for avoiding the discomforts in dental treatments, namely, a smooth transition from endodontic to prosthodontic treatment can be achieved.

Coronal Sealing Capacity of Temporary Restorative Materials in Pediatric Dentistry: A Comparative Study

Aims

The aim of this in vitro study is to compare the coronal microleakage of three common temporary restorative materials, namely Coltosol, Compoglass, and Zonalin, used in pediatric dentistry after endodontic treatment at different time intervals (1 week, 1, and 2 months) using dye penetration.

Materials and methods

Access cavities were prepared in 72 intact extracted premolar teeth. The samples were divided into three groups (n = 24) and filled with Coltosol, Compoglass, or Zonalin. After thermal cycling for 500 cycles (5–55°C), the teeth were immersed in 1% methylene blue dye at 37°C for 1 week (n = 8), 1 month (n = 8), and 2 months (n = 8). The samples were sectioned buccolingually, and the linear depth of dye penetration was measured using a stereomicroscope at 16 × magnification. The data were analyzed using Kruskal–Wallis test.

Results

There were no significant differences in the microleakage values of Coltosol and Zonalin or Zonalin and Compoglass groups at 1 week (p > 0.05) or 1 month (p > 0.05) intervals, but a significant difference was noted between Coltosol and Compoglass groups (p < 0.01); Coltosol provided a more favorable coronal seal. No significant difference was found among the experimental groups at the 2-month interval (p > 0.05).

Conclusion

At 1 week or 1 month of use, Coltosol showed better coronal seal. At 2 months, there was no significant difference apparent between the groups. A longer time lapse was associated with an increased likelihood of microleakage.

How to cite this article

Milani S, Seraj B, Heidari A, Mirdamadi A, Shahrabi M. Coronal Sealing Capacity of Temporary Restorative Materials in Pediatric Dentistry: A Comparative Study. Int J Clin Pediatr Dent 2017;10(2):115-118.

Restoration of the root canal treated tooth

When considering endodontically treated teeth, the quality of the restoration is important from the outset. It sheds light into possible causes of pulp necrosis or failure of endodontic treatment and influences the outcome of future endodontic treatment. A tooth undergoing endodontic treatment requires an effective coronal seal during and following completion of endodontic treatment. This paper discusses, using the available literature, the maintenance of optimal coronal seal and coronal integrity during and after root canal treatment.

Delayed replantation of avulsed tooth with 15-hours extra-oral time: 3-year follow-up

BACKGROUND

Avulsion is one of the most serious injuries of the tooth which is most commonly seen in young children and occurs in the upper front teeth. Immediate transplantation of the avulsed tooth is recommended treatment and results in good prognosis although this may not be always possible.

CASE REPORT

The present case highlights the 3-year follow-up of delayed replantation (after 15h) of maxillary central incisor which was avulsed due to trauma. The complications seen in the present case were ankylosis and inflammatory resorption, but clinically the tooth was asymptomatic and maintains the esthetics of the individual signifying the importance of delayed replantation even after prolonged extra-oral time.

CLINICAL IMPLICATIONS AND CONCLUSION

Although complications like ankylosis or root resorption may be unavoidable, delayed replantation of avulsed tooth may be a good alternative to prosthesis (implant or fixed partial denture) till the growth is completed due to preservation of the alveolar bone and psychological benefit to the patient. Also efforts should be made to educate and update children, teachers and parents regarding management of avulsed tooth at accident site and also the dentists regarding its management in dental office.

Role of provisional restorations in endodontic therapy

Root-canal treatment can be carried out in single visit in vital, non-infected teeth, eliminating the need for dressing and provisionalization. Many clinical cases with infected canals require dressing with antibacterial medicaments in a multivisit treatment in which effective provisionalization for different periods of time becomes mandatory. Successful root-canal treatment requires effective mechanical and chemical debridement, elimination of bacteria and pulp tissue remnants and proper canal shaping to facilitate effective obturation. Lack of satisfactory temporary restorations during endodontic therapy ranked second amongst the contributing factors in continuing pain after the commencement of treatment. This review aims to provide an overview of the materials used for provisionalization during and immediately after endodontic treatment.

Fracture patterns of glass-ionomer cement overlays versus stainless steel bands during endodontic treatment: an ex-vivo study

AIM

To compare fracture patterns of posterior teeth temporized with: mesio-occlusal-distal (MOD) glass-ionomer cement (GIC) interim restorations, stainless steel (SS) bands, GIC dome overlays and GIC dome overlays with occlusal temporary restorations.

METHODOLOGY

The root canals of 92 extracted human premolars and molars were prepared with rotary NiTi instruments and dressed with calcium hydroxide paste prior to cavity preparation for standardized MOD restorations. Teeth were divided into four groups (n = 23) and temporarily restored with: GIC interim restorations (GIC group), stainless steel bands (SS group), GIC dome overlays (GIC-O group) or GIC dome overlays with intermediate restorative material (IRM) in the access cavities (GIC-IRM group). Teeth were subjected to compressive axial load until fracture; fracture forces and fracture modes were recorded. Statistical analysis included Kaplan-Meier plots, Cox proportional hazards model, one-way analysis of variance, chi-square and Fisher's exact tests.

RESULTS

There was a significantly higher risk of failure in the GIC group compared with the SS (P < 0.001), GIC-O (P < 0.001) and GIC-IRM (P = 0.001) groups. The mean fracture force for SS was significantly higher than GIC-O (P = 0.03) and GIC-IRM (P < 0.001). GIC fracture force was significantly lower than all other groups (P < 0.001). Significantly fewer unfavourable fractures were observed in SS compared with GIC (P = 0.001), GIC-O (P = 0.007) and GIC-IRM (P < 0.001).

CONCLUSIONS

Glass-ionomer cement dome overlays with reduced cuspal height and occlusal inclines may be recommended for broken-down posterior teeth, without any risk of poor aesthetics, gingival irritation or further proximal tooth structure loss. Stainless steel bands may only need to be used in extensively broken-down teeth or in the presence of parafunctional habits.

Sealing ability of various restorative materials as coronal barriers between endodontic appointments

AIM

To evaluate and compare the microleakage of various restorative materials used as coronal barriers between endodontic appointments.

MATERIALS AND METHODS

Eighty extracted human permanent posterior teeth were prepared for standardized access cavities with dimensions of 4 × 4 × 4 mm. The teeth were then randomly divided into four groups; Kalzinol, Caviton, GC Fuji IX and GC Fuji II LC. After incubation, the samples were immersed in 2% methylene blue for 7 days. The depth of penetration was measured using a digital macroscope after longitudinal sectioning of each tooth. Kruskal-Wallis (p < 0.05) and multiple Mann-Whitney test with Bonferroni correction (p < 0.008) were used for data analysis.

RESULTS

The degree of microleakage varied at the material/ tooth interface among the test materials, and the difference was statistically significant (p < 0.05). GC Fuji II LC group showed the least median microleakage value (0.8105 ± 0.305), followed by Caviton (1.1885 ± 0.396), GC Fuji IX (3.3985 ± 0.305) and Kalzinol (4.161 ± 0.853).

CONCLUSION

Within the limitations of this study, GC Fuji II LC exhibited the best marginal seal, and has the potential to be used as a suitable coronal barrier between endodontic appointments.

CLINICAL SIGNIFICANCE

Given the prime importance that dental practitioners should thoroughly restore any tooth with a suitable coronal barrier between endodontic appointments, this study shows that Fuji II LC has the ability to maintain a hermetic seal for 7 days.

Strategies for the endodontic management of concurrent endodontic and periodontal diseases

Endodontic and periodontal diseases can provide many diagnostic and management challenges to clinicians, particularly when they occur concurrently. As with all diseases, a thorough history combined with comprehensive clinical and radiographic examinations are all required so an accurate diagnosis can be made. This is essential since the diagnosis will determine the type and sequence of treatment required. This paper reviews the relevant literature and proposes a new classification for concurrent endodontic and periodontal diseases. This classification is a simple one that will help clinicians to formulate management plans for when these diseases occur concurrently. The key aspects are to determine whether both types of diseases are present, rather than just having manifestations of one disease in the alternate tissue. Once it is established that both diseases are present and that they are as a result of infections of each tissue, then the clinician must determine whether the two diseases communicate via the periodontal pocket so that appropriate management can be provided using the guidelines outlined. In general, if the root canal system is infected, endodontic treatment should be commenced prior to any periodontal therapy in order to remove the intracanal infection before any cementum is removed. This avoids several complications and provides a more favourable environment for periodontal repair. The endodontic treatment can be completed before periodontal treatment is provided when there is no communication between the disease processes. However, when there is communication between the two disease processes, then the root canals should be medicated until the periodontal treatment has been completed and the overall prognosis of the tooth has been reassessed as being favourable. The use of non-toxic intracanal therapeutic medicaments is essential to destroy bacteria and to help encourage tissue repair.

Bacterial and dye penetration through interim restorations used during endodontic treatment of molar teeth

INTRODUCTION

The purpose of this study was to investigate the association between dye and bacterial penetration through interim restorations used during endodontic treatment.

METHODS

Sixty-four extracted human teeth were used, with 2 teeth each as positive and negative controls. Endodontic access with a mesio-occluso-distal cavity was prepared. Palatal cusps of maxillary molars and buccal cusps of mandibular molars were removed. Cotton was placed over the canals and covered with Cavit. Thirty teeth were restored with Ketac Silver (KS) and 30 with KS reinforced with a stainless steel band (KSSB). Samples were submersed in India ink mixed with brain heart infusion broth containing Streptococcus gordonii. After 3 months of simulated chewing, structural integrity and dye and bacterial penetration were assessed.

RESULTS

Positive controls had both dye and bacterial penetration. Negative controls had no dye or bacterial penetration. All KS restorations debonded, whereas 18 KSSB restorations (60%) debonded. KS restorations were 1.67 times more likely to debond than KSSB restorations (Fisher exact test). KS was 1.3 times more likely to have dye penetration than KSSB (Fisher exact test) and 3 times more likely to have bacterial penetration, although not statistically significant (chi(2) test). Overall, 88.3% of specimens had dye penetration, and 20% had bacterial penetration. This 68.3% difference indicated no association between dye and bacterial penetration (exact McNemar test).

CONCLUSIONS

Stainless steel bands helped maintain structural integrity of KS restorations under masticatory function. Bands helped prevent dye penetration but not bacterial penetration. There was no association between dye and bacterial penetration.

Experimental Model: Dye Penetration of Extensive Interim Restorations Used during Endodontic Treatment while under Load in a Multiple Axis Chewing Simulator

The purpose of this study was to design an experimental model that allowed extensive endodontic interim restorations to be tested for dye penetration while under simulated masticatory load. Extracted premolar teeth had standardized mesio-occluso-distal cavities prepared, and the root canals were instrumented. A cotton wool pellet was placed in the pulp chamber, and the cavities were restored with Cavit, IRM, Ketac-Fil Plus, Ketac-Silver, or composite resin (Z100). They were subjected to the equivalent of 3 months of clinical load while exposed to methylene blue dye. Results of this study could not support IRM as a suitable interim endodontic restorative material to use in extensive cavities. The dye penetration in the Ketac-Fil Plus and Ketac-Silver specimens was not predictable, and the results suggested Cavit and Z100 composite resin require further investigations as potentially useful materials for this purpose.