Post Placement and Restoration of Endodontically Treated Teeth: A Literature Review
Richard S. Schwartz, DDS, and James W. Robbins, DDS, MA
Postprocedural Problems in an Overdenture Population: A Longitudinal Study
Ronald L. Ettinger, BDS, MDS, DDSc, and Fang Qian, PhD
Association of Enterococcus faecalis With Different Forms of Periradicular Diseases
Isabela N. Rôças, DDS, MSc, José F. Siqueira Jr., DDS, MSc, PhD, and Kátia R. N. Santos, BS, MSc, PhD
Morphology of the Physiological Foramen: I. Maxillary and Mandibular Molars
Benjamín Briseño Marroquín, Prof. Dr. med.dent., Mohammed A. A. El-Sayed, Dr. med.dent., and Brita Willershausen-Zönnchen, Prof. Dr. med.dent.
Substance P Expression Is Elevated in Inflamed Human Periradicular Tissue
Levent I. Tuncer, BDS, Tayfun Alac¸ am, DDS, and Barbaros Oral, MD, PhD
Treatment Outcome in Endodontics—The Toronto Study. Phase II: Initial Treatment
Mahsa Farzaneh, DDS, MSc, Sarah Abitbol, DDS, MSc, Herenia P. Lawrence, DDS, PhD, and Shimon Friedman, DMD
Comparison of Type 1 and Type 2 Cytokine Production by Mononuclear Cells Cultured With Streptococcus mutans and Selected Other Caries Bacteria
Chin-Lo Hahn, PhD, DDS, Al M. Best, PhD, and John G. Tew, PhD
Proposed Role of Embedded Dentin Chips for the Clinical Failure of Nickel-Titanium Rotary Instruments
Satish B. Alapati, BDS, William A. Brantley, PhD, Timothy A. Svec, DDS, MS, MS, John M. Powers, PhD, John M. Nusstein, DDS, MS and Glenn S. Daehn, PhD
Tissue Response to a New Methacrylate-Based Root Canal Sealer: Preliminary Observations in the Subcutaneous Connective Tissue of Rats
Osvaldo Zmener, DDS, Dr. Odont.
An Evaluation of Microbial Leakage in Roots Filled with a Thermoplastic Synthetic Polymer-Based Root Canal Filling Material (Resilon)
Guy Shipper, BDS, MDent, Dag Ørstavik, DDS, PhD, Fabricio Batista Teixeira, DDS, MSc, PhD, and Martin Trope, BDS, DMD
Endodontic Treatment of a Patient With Huntington’s Disease
Henry Bradford, DMD, Leandro R. Britto, BDS, MS, Gustavo Leal, DDS, and Joseph Katz, DMD
Effect of NaOCl on Bond Strengths of Bonding Agents to Pulp Chamber Lateral Walls
Bora Ozturk, DDS, PhD, and Füsun Özer, DDS, PhD
Effect of Propolis on Human Fibroblasts from the Pulp and Periodontal Ligament
Abdul Al-Shaher, BDS, MDS, James Wallace, DDS, MDS, MSD, MS, Sudha Agarwal, PhD, Walter Bretz, DDS, MPH, Dr.PH, and Dean Baugh, DDS
Effect of Dentin on the Antibacterial Activity of Dentin Bonding Agents
G. Schmalz, Z. Ergücü, and K.-A. Hiller
Post Placement and Restoration of Endodontically Treated Teeth: A Literature Review
Richard S. Schwartz, DDS, and James W. Robbins, DDS, MA
The restoration of endodontically treated teeth is a topic that is extensively studied and yet remains controversial from many perspectives. This article reviews the major pertinent literature on this topic, with an emphasis on major decision-making elements in post placement and restoration of Endodontically treated teeth. Recommendations are made for treatment planning, materials, and clinical practices from restorative and endodontic perspectives.
Postprocedural Problems in an Overdenture Population: A Longitudinal Study
Ronald L. Ettinger, BDS, MDS, DDSc, and Fang Qian, PhD
This study reports on endodontic and other postprocedural problems experienced by overdenture patients from 1973 to 1996. There were 395 subjects enrolled in the study; 273 fulfilled the recall criteria. At recall, all subjects were examined by a single examiner, and appropriate maintenance care was performed. The 273 subjects had 666 abutments and 626 endodontically treated teeth; of these, 51 subjects had postprocedural problems in 81 teeth. Thus, 87.1% of the endodontically treated teeth had no postprocedural problems, and 12.9% had postprocedural problems. Of the subpopulation with postprocedural problems, the most common problem was endodontically treated teeth developing periradicular lesions (37.0%) because of recurrent caries causing loss of the restoration sealing the root canal. Twenty of the 30 teeth were successfully retreated. The next most common problem was vertical root fractures (30.9%), followed by vital teeth developing periradicular lesions (19.8%). Most of the failures could have been prevented by better oral hygiene. Vertical root fractures were statistically associated with abutments in the maxilla and opposed by natural teeth; protection of these abutments with thimble crowns could prevent fractures.
Association of Enterococcus faecalis With Different Forms of Periradicular Diseases
Isabela N. Rôças, DDS, MSc, José F. Siqueira Jr., DDS, MSc, PhD, and Kátia R. N. Santos, BS, MSc, PhD
Data from culture studies have revealed that Enterococcus faecalis is occasionally isolated from primary endodontic infections but frequently recovered from treatment failures. This molecular study was undertaken to investigate the prevalence of E. faecalis in endodontic infections and to determine whether this species is associated with particular forms of periradicular diseases. Samples were taken from cases of untreated teeth with asymptomatic chronic periradicular lesions, acute apical periodontitis, or acute periradicular abscesses, and from root-filled teeth associated with asymptomatic chronic periradicular lesions. DNA was extracted from the samples, and a 16S rDNAbased nested polymerase chain reaction assay was used to identify E. faecalis. This species occurred in seven of 21 root canals associated with asymptomatic chronic periradicular lesions, in one of 10 root canals associated with acute apical periodontitis, and in one of 19 pus samples aspirated from acute periradicular abscesses. Statistical analysis showed that E. faecalis was significantly more associated with asymptomatic cases than with symptomatic ones. E. faecalis was detected in 20 of 30 cases of persistent endodontic infections associated with root-filled teeth. When comparing the frequencies of this species in 30 cases of persistent infections with 50 cases of primary infections, statistical analysis demonstrated that E. faecalis was strongly associated with persistent infections. The average odds of detecting E. faecalis in cases of persistent infections associated with treatment failure were 9.1. The results of this study indicated that E. faecalis is significantly more associated with asymptomatic cases of primary endodontic infections than with symptomatic ones. Furthermore, E. faecalis was much more likely to be found in cases of failed endodontic therapy than in primary infections.
Morphology of the Physiological Foramen: I. Maxillary and Mandibular Molars
Benjamín Briseño Marroquín, Prof. Dr. med.dent., Mohammed A. A. El-Sayed, Dr. med.dent., and Brita Willershausen-Zönnchen, Prof. Dr. med.dent.
Information concerning the anatomy of the physiological foramen is limited. The aim of this study was to investigate the distance between the physiological and anatomical apex, accessory foramina frequency, and the shape and diameter of the physiological foramen in maxillary and mandibular molars. The apical anatomy of 523 maxillary and 574 mandibular molars from an Egyptian population was investigated by means of a computeraided stereomicroscope (40× magnification). The following results were obtained:
(a) There was a high percentage of two physiological foramina in mesial (87.06%) and mesiobuccal (71.15%) roots of mandibular and maxillary first molars, respectively.
(b) There was a high frequency of accessory foramina in maxillary mesiobuccal (33%) and mandibular mesial (26%) roots.
(c) The most common physiological foramen shape was oval (70%).
(d) The mean of the narrow and wide physiological foramen diameters was as follows:
0.20 to 0.26 mm in mandibular molars
0.18 to 0.25 mm in the maxillary mesiobuccal and distobuccal root
0.22 to 0.29 mm in the maxillary palatal root
Substance P Expression Is Elevated in Inflamed Human Periradicular Tissue
Levent I. Tuncer, BDS, Tayfun Alac¸ am, DDS, and Barbaros Oral, MD, PhD
Substance P is a neuropeptide believed to be a major mediator of neurogenic inflammation. The aim of our study was to evaluate whether substance P levels are elevated in the clinical biopsies collected from inflamed periradicular or control tissue. In this study, the presence of substance P was examined in infected human periradicular granulation tissue and control tissue. Sections from 19 periradicular granulomas and pulp tissues from two healthy control teeth were examined using the immunohistochemical method. Substance P-expressing neutrophils, macrophages, and plasma cells were found in both acute and chronic periradicular granulomas. In addition, we observed the presence of neutrophils expressing substance P without concurrent clinical symptoms of acute inflammation. Our results are consistent with the hypothesis that substance P may be released from neutrophils in the inflamed region, and thus, substance P may modulate clinical inflammatory response by release from either neuronal or immunocompetent cell populations.
Treatment Outcome in Endodontics—The Toronto Study. Phase II: Initial Treatment
Mahsa Farzaneh, DDS, MSc, Sarah Abitbol, DDS, MSc, Herenia P. Lawrence, DDS, PhD, and Shimon Friedman, DMD
The 4- to 6-yr outcome of initial (first-time) endodontic treatment was assessed for Phase II of the “Toronto Study.” In total, 442 teeth were treated by using flared preparation and vertical compaction of warm gutta-percha or step-back preparation and lateral compaction. With 126 teeth excluded (discontinuers: deceased and relocated patients), 163 dropouts, and 31 extracted, 122 (48% recall) were examined for outcome: “healed” (no apical periodontitis [AP], signs, symptoms) or “diseased” (AP, signs, or symptoms). Phase II was analyzed separately and combined with Phase I (n = 242), using Chi-square and Fisher’s exact tests (p ≤ 0.05). The healed rate (combined sample, 85%) differed significantly for preoperative AP (absent, 93%; present, 79%), treatment technique (flared preparation and vertical compaction, 90%; stepback preparation and lateral compaction, 80%), gender (females, 90%; males, 79%), number of roots (1–92%; ≥ 2–81%), and root-filling length (adequate, 87%; inadequate, 77%). Logistic regression revealed increased risk of disease for preoperative AP (odds ratio = 3.3) and technique (odds ratio = 2.3). This study confirmed AP and highlighted treatment technique as the main predictors of outcome in initial treatment.
Comparison of Type 1 and Type 2 Cytokine Production by Mononuclear Cells Cultured With Streptococcus mutans and Selected Other Caries Bacteria
Chin-Lo Hahn, PhD, DDS, Al M. Best, PhD, and John G. Tew, PhD
A feature of pulpal immune responses is the predominance of type 1 cytokine mRNA under shallow caries and a mixed (type 1/type 2) profile under deep caries. These results prompted an examination of the cytokine profiles induced by bacteria in shallow caries (Streptococcus mutans and Actinomyces viscosus) and deep caries (Lactobacillus casei, Pseudoramibacter alactolyticus, and Prevotella intermedia). All isolates induced interferon-y and interleukin-10, whereas interleukin-4 and interleukin-2 titers were low to undetectable. S. mutans was the most potent and persistent interferon-y inducer. Differences in interleukin-10 were apparent at low doses but were less dramatic, with L. casei the dominant producer. S. mutans induced substantially more interferon-y than interleukin-10 over all doses and time points, suggesting strong type 1 polarization. P. alactolyticus induced significantly more interleukin-10 than interferon-y at higher concentrations, suggesting polarization toward type 2. A similar amount of interferon-_and interleukin-10 induced by L. casei, A. viscosus, and P. intermedia reflected a mixed profile. A better understanding of pulpal immune response to caries bacteria may enable us to develop an immune system-based pulp therapy in the future.
Proposed Role of Embedded Dentin Chips for the Clinical Failure of Nickel-Titanium Rotary Instruments
Satish B. Alapati, BDS, William A. Brantley, PhD, Timothy A. Svec, DDS, MS, MS, John M. Powers, PhD, John M. Nusstein, DDS, MS and Glenn S. Daehn, PhD
Discarded ProFile and ProTaper nickel-titanium rotary instruments, with unknown history of clinical use, were obtained from graduate endodontic clinics at Ohio State University and University of Texas Health Science Center at Houston Dental Branch. These discarded instruments and as-received instruments of both types were examined with a scanning electron microscope to investigate effects of clinical use and causes of failure. For used ProTaper instruments, dentinal debris was wedged mostly in narrow, radial, land-type regions and less on convex flute surfaces. For used ProFile instruments, dentinal debris was wedged mostly in the metal rollover and on concave flute surfaces. Used instruments of both types exhibited widened machining grooves, and elongated and stretched rollover. Dentin chips were wedged in surface microcracks that appeared to propagate from original machining flaws and widen during in vivo root canal preparation. From our observational study, wedged dentinal deposits seem to play a pivotal role for clinical failure of these instruments.
Tissue Response to a New Methacrylate-Based Root Canal Sealer: Preliminary Observations in the Subcutaneous Connective Tissue of Rats
Osvaldo Zmener, DDS, Dr. Odont.
Silicone tubes filled with EndoRez, a methacrylatebased root canal sealer, were implanted in the subcutaneous connective tissue of the rat. Solid, silicone rods of the same size as the tubes also were implanted and used as negative controls. The tissue reaction to test and control materials was histologically studied and analyzed by elemental electron- microprobe analysis. After 10, 30, 90, and 120 days of implantation, different grades of tissue reaction to the tested materials were recorded. A granulomatous tissue containing numerous polymorphonuclear leukocytes, lymphocytes, and plasmocytes, as well as macrophages and foreignbody giant cells with engulfed material in their cytoplasm, was initially observed in contact with EndoRez. Fibroblasts and newly formed vessels also were observed. This cellular profile persisted after 30 days. The severity of the reaction decreased with time, and connective tissue healing was observed at the 120-day observation period, even though some specimens exhibited a slight, persistent, inflammatory cell infiltration. The electronmicroprobe analysis of the tissues revealed the presence of heavy components of EndoRez in all observation periods. In contact with the controls, there was an initially slight concentration of inflammatory cells. This reaction rapidly subsided after 30 days, and a fibrous connective tissue encapsulation, free of inflammatory cells, could be observed at the 90- and 120-day observation periods.
An Evaluation of Microbial Leakage in Roots Filled with a Thermoplastic Synthetic Polymer-Based Root Canal Filling Material (Resilon)
Guy Shipper, BDS, MDent, Dag Ørstavik, DDS, PhD, Fabricio Batista Teixeira, DDS, MSc, PhD, and Martin Trope, BDS, DMD
The purpose of this study was to compare bacterial leakage using Streptococcus mutans and Enterococcus faecalis through gutta-percha and a thermoplastic synthetic polymer-based root filling (Resilon) using two filling techniques during a 30-day period. Teeth were decoronated, roots prepared to a length of 16 mm, and instrumented to ISO sizes 40 to 50. A total of 156 roots were randomly divided into 8 groups of 15 roots (groups 1–8) and 3 control groups (12 roots each). Roots were filled using lateral and vertical condensation techniques with gutta-percha and AH 26 sealer (groups 1 and 2) or with gutta-percha and Epiphany sealer (groups 3 and 4). Groups 5 and 6 were filled with Resilon and Epiphany sealer using the lateral or vertical condensation techniques. A split chamber microbial leakage model was used in which S. mutans placed in the upper chamber could reach the lower chamber only through the filled canal. Groups 7 and 8 were identical to groups 5 and 6 respectively; however, E. faecalis was used to test the leakage. Positive controls were filled with Resilon (12 roots) and gutta-percha (12 roots) without sealer and tested with bacteria, whereas negative controls (12 roots) were sealed with wax to test the seal between chambers. All but one positive control leaked within 24 h, whereas none of the negative controls leaked. Resilon showed minimal leakage (group 8: one leakage; groups 5–7: each with two leakages), which was significantly less than gutta-percha, in which approximately 80% of specimens with either technique or sealer leaked. Kruskal-Wallis test showed statistical significance when all groups were compared (p<0.05). Mann-Whitney U test compared the respective groups and found Resilon groups superior to gutta-percha groups (p < 0.05).
Endodontic Treatment of a Patient With Huntington’s Disease
Henry Bradford, DMD, Leandro R. Britto, BDS, MS, Gustavo Leal, DDS, and Joseph Katz, DMD
Huntington’s disease is a lethal autosomal dominant disorder that affects men and women equally. The prevalence of Huntington’s disease in North America is 5 to 10 per 100,000 people. It is characterized by regular personality changes, dementia, and choreiform (dance-like) movements. Literature concerning dental treatment of patients who have been diagnosed with this type of disease is scarce. Continuous ingestion of medications to control the symptoms of this disease leads to xerostomia, which, maximized by unrestrained movements, often leads to progressive tooth decay, irreversible pulpitis, and tooth loss. Maintenance of teeth in patients with this type of disease is desirable and challenging. Like any patient, a comprehensive treatment plan needs to be developed with equal emphasis on restoration and home care. This case report illustrates how a morphologically difficult endodontic procedure can be successfully administered in a patient diagnosed with HD. Overall case success was attributed to a dental team approach and short-duration appointments to limit patient stress.
Effect of NaOCl on Bond Strengths of Bonding Agents to Pulp Chamber Lateral Walls
Bora Ozturk, DDS, PhD, and Füsun Özer, DDS, PhD
The objective of this study was to evaluate the effects of 5% NaOCl on bond strengths of four bonding systems—Clearfil SE Bond, Prompt L-Pop, Prime&Bond NT, and Scotchbond Multi Purpose Plus—to pulp chamber mesial walls. Forty mandibular third molar teeth were used in the study. The pulp chambers of the first 20 teeth were restored with bonding agents and composite resins after 5% NaOCl irrigation, and the remaining teeth were restored without 5% NaOCl treatment. Each bonding group had five teeth. Three rectangular thin sticks (1 ± 0.03mm²) were obtained from the mesial wall of restored pulp chambers by horizontal sectioning. In general, NaOCl application decreased the bond strength values of the bonding agents. Both Clearfil SE Bond and Prompt L-Pop without NaOCL showed higher bond strength values than the other bonding groups. In NaOCl-applied groups, Clearfil SE Bond had the highest bond strength. It can be concluded that self-etching bonding systems are more successful than the other systems in bonding to pulp chamber dentinal wall and that NaOCl reduces bond strength.
Effect of Propolis on Human Fibroblasts from the Pulp and Periodontal Ligament
Abdul Al-Shaher, BDS, MDS, James Wallace, DDS, MDS, MSD, MS, Sudha Agarwal, PhD, Walter Bretz, DDS, MPH, Dr.PH, and Dean Baugh, DDS
Propolis, a flavonoid-rich product of honey comb, exhibits antibacterial and anti-inflammatory properties. In this study, we examined the tolerance of fibroblasts of the periodontal ligament (PDL) and dental pulp to propolis and compared with that of calcium hydroxide in vitro. Cells from human dental pulp and PDL were obtained from healthy third molars and subjected to various concentrations of propolis (0–20 mg/ml) and calcium hydroxide (0–250 mg/ml). The cell viability after propolis treatment was analyzed by crystal violet staining of the cells followed by spectrophotometric analysis. Data revealed that exposure of PDL cells or pulp fibroblasts to 4 mg/ml or lower concentrations of propolis resulted in >75% viability of cells. On the contrary, calcium hydroxide 0.4 mg/ml was cytotoxic and <25% of the cells were found to be viable. Further investigations may find propolis to be a possible alternative for an intracanal antimicrobial agent.
Effect of Dentin on the Antibacterial Activity of Dentin Bonding Agents
G. Schmalz, Z. Ergücü, and K.-A. Hiller
Dentin bonding agents with antibacterial effects may inhibit secondary caries formation and pulp inflammation by eliminating residual bacteria in and on dentin. Therefore, the antibacterial effects of Prime & Bond NT (PB), Prime & Bond NT without fluoride (PBNF), Gluma Comfort Bond (GL), ABF, Xeno CF II (XE), 2-hydroxyethyl methacrylate (HEMA), triethylene glycol dimethacrylate (TEGDMA), and 0.2% chlorhexidine were tested against Streptococcus mutans, S. sobrinus, and Lactobacillus acidophilus using the agar-diffusion method with and without bovine-dentin disks (200 μm and 500 μm thickness) placed between the bacteria and the test substances. Without dentin, ABF Primer showed growth inhibition for all bacterial strains. XE inhibited S. mutans and S. sobrinus, and PB S. sobrinus. ABF Bonding inhibited L. acidophilus. PBNF, HEMA, and TEGDMA did not have any antibacterial effects. Dentin disks of 500 μm thickness reduced the inhibitory effect of chlorhexidine to 23% to 54% compared with direct application. ABF Primer (nonpolymerized) produced inhibition zones against all tester strains regardless of dentin disks interposed or not. XE (against S. mutans and S. sobrinus) and PB (against S. sobrinus) did not produce any inhibition zones on 200 μm thick dentin. After polymerization, the ABF system did not inhibit bacterial growth on 200 μm thick dentin disks. A dentin barrier reduces significantly the antibacterial activity of chlorhexidine and dentin bonding agents.