Phages in a thermoreversible sustained-release formulation targeting E. faecalis in vitro and in vivo

Introduction

Enterococcus faecalis is a key pathogen recovered from root canals when conventional treatment fails. Phage therapy has generated new interest in combating pathogens. A sustained-release formulation using specific phages against E. faecalis may offer an alternative approach.

Objectives

To evaluate the efficacy of anti-E. faecalis phages formulated in a thermo- sustained-release system against E. faecalis in vitro and in vivo.

Methods

EFDG1 and EFLK1 phages were formulated with poloxamer P407. Gelation time, phage survival, activity and toxicity were evaluated. Lytic activity was evaluated in vitro against E. faecalis at various growth phases, including anti-biofilm activity. Methods included viable bacterial count (CFU/mL), biofilm biomass determination and electron microscopy (live/dead staining). Further evaluation included infected incisors in an in vivo rat model. Anti-E. faecalis phage-cocktail suspension and sustained-release phage formulation were evaluated by viable bacterial count (CFU/mL), histology, scanning electron microscopy (SEM) and 16S genome sequencing of the microbiota of the root canal.

Results

Gelation time for clinical use was established. Low toxicity and a high phage survival rate were recorded. Sustained-release phages reduced E. faecalis in logarithmic (4 logs), stationary (3 logs) and biofilm (4 logs) growth phases. Prolonged anti-biofilm activity of 88% and 95% reduction in biomass and viable counts, respectively, was recorded. Reduction of intracanal viable bacterial counts was observed (99% of enterococci) also seen in SEM. Phage treatment increased Proteobacteria and decreased Firmicutes. Histology showed reduced periapical inflammation and improved healing following phage treatment.

Conclusion

Poloxamer P407 formulated with phages has an effective and long-lasting effect in vitro and in vivo targeting E. faecalis.

Pulp therapy for primary and immature permanent teeth: an overview

Pulp therapy for pediatric patients aims to alleviate pulpal infection, relieve associated symptoms, and, ultimately, preserve the tooth. Primary teeth adequately retain space for their successors and have been described as "the best space maintainers." Therefore, the decision to extract a primary tooth should take into consideration occlusal growth and development as well as the potential outcome of pulp therapy. Maintaining pulpal vitality in young permanent teeth is essential for continued root formation; if vitality is lost, the root will cease growth and remain at an unfavorable length. A systematic approach to diagnosis and treatment planning is imperative, and a good history of signs and symptoms and a detailed evaluation of radiographs are prerequisites to accurate diagnosis. The purpose of this review is to aid dental professionals in correctly establishing a pulpal diagnosis and selecting the appropriate method of pulp therapy to achieve a successful outcome. The article discusses contemporary views on indications and pulp medicaments and presents step-by-step descriptions of pulp treatments for both primary and immature permanent teeth.

A 10-year trend of dental treatments under general anesthesia of children in Taipei Veterans General Hospital

BACKGROUND

General anesthesia (GA) as a pediatric dental procedure is a well-established method of behavior management. However, studies of pediatric dentistry under GA have mostly focused on handicapped patients, and various retrospective studies in Taiwan have mainly reviewed only a limited number of years. The purpose of the present study was to report trends in pediatric dental treatment performed under GA over the past 10 years.

METHODS

A retrospective review of the hospital records of patients receiving dental treatment under GA from 2006 until 2015 was performed. The patients were divided into three age groups: < 3 years, 3-6 years, and > 6 years. A range of information including basic patient characteristics and types of dental treatment was identified and then analyzed.

RESULTS

A total of 791 cases (< 3 years old: 65 cases, 3-6 years old: 492, > 6 years old: 235; 549 male, 242 female) were treated under GA. The case number was found to have increased from 94 during 2006-2007 to 238 during 2014-2015, with the increase being especially pronounced among those aged 3-6 years (2006-2007: 49, 2014-2015: 165). The most common treatments (extraction, restoration, and pulp therapy) were associated with multiple dental caries (684, 86.4%). The < 3-years-old group was characterized by the highest decayed, extracted, and filled surface and decayed, missing, and filled surface indices; the highest mean number of treated teeth; and the highest mean number of treated teeth by composite resin fillings. The 3-6-years-old group had the highest number of primary teeth extractions. The > 6-years-old group had the lowest mean number of treated teeth by stainless-steel crowns (SSCs) and fewest cases treated with pulp therapy. From 2011 onwards, the number of primary tooth extractions significantly increased, while in 2013, there was a crossover whereby the SSC count surpassed the composite resin filling count.

CONCLUSION

Over the past 10 years, there has been an increased use of GA for pediatric dental treatments, in particular, in cases with multiple dental caries. In addition, there has also been an increasing trend towards extraction of primary teeth and the use of SSCs.

[The importance of pulp therapy in deciduous teeth]

Preserving primary teeth is crucial for maintaining the maxillary growth, aesthetics, mastication, and speech and for preventing from abnormal habits. Given the peculiar anatomy of the primary tooth, caries grow faster and more frequently to the pulp. In pediatric dentistry, new methods and enhanced material have been recently released on the market and broadened the field of treatments. In this paper, we review the pulp diseases affecting children and focus on the current root canal therapies that favour the physiological primary tooth loss.

WITHDRAWN: Pulp management for caries in adults: maintaining pulp vitality

BACKGROUND

There is a range of treatment options for the management of the pulp in extensively decayed teeth. These include direct and indirect pulp capping, pulpotomy or pulpectomy. If the tooth is symptomatic or if there are periapical bone changes, then endodontic treatment is required. However, if the tooth is asymptomatic but the caries is extensive, there is no consensus as to the best method of management. In addition, there has been a recent move towards using alternative materials and methods such as the direct or indirect placement of bonding agents and mineral trioxide aggregate.Most studies have investigated the management of asymptomatic carious teeth with or without an exposed dental pulp using various capping materials (e.g. calcium hydroxide, Ledermix, Triodent, Biorex, etc.). However, there is no long term data regarding the outcome of management of asymptomatic, carious teeth according to different regimens.

OBJECTIVES

This study aims to assess the effectiveness of techniques used to treat asymptomatic carious teeth and maintain pulp vitality.

SEARCH METHODS

Electronic searches of the following databases were undertaken: The Cochrane Oral Health Group's Trials Register (March 2006), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2006, Issue 1), MEDLINE (1966 to week 4, February 2006), EMBASE (1974 to 13 March 2006), National Research Register (March 2006), Science Citation Index - SCISEARCH (1981 to March 2006). Detailed search strategies were developed for each database. Handsearching and screening of reference lists were undertaken. There was no restriction with regard to language of publication.

SELECTION CRITERIA

Studies included were randomised controlled trials (RCTs). Asymptomatic vital permanent teeth with extensive caries were included. Studies were those which compared techniques to maintain pulp vitality. Outcome measures included clinical success and adverse events.

DATA COLLECTION AND ANALYSIS

Data were independently extracted by three review authors. Authors were contacted for details of randomisation and withdrawals and a quality assessment was carried out. The Cochrane Collaboration's statistical guidelines were followed.

MAIN RESULTS

Only four RCTs were identified. Interventions examined included: Ledermix, glycerrhetinic acid/antibiotic mix, zinc oxide eugenol, calcium hydroxide, Cavitec, Life, Dycal, potassium nitrate, dimethyl isosorbide, and polycarboxylate cement. Only one study showed a statistically significant finding; potassium nitrate/dimethyl isosorbide/polycarboxylate cement resulted in fewer clinical symptoms than potassium nitrate/polycarboxylate cement or polycarboxylate cement alone when used as a capping material for carious pulps.

AUTHORS' CONCLUSIONS

It was disappointing that there were so few studies which could be considered as being suitable for inclusion in this review. The findings from this review do not suggest that there should be any significant change from accepted conventional practice procedures when the pulp of the carious tooth is considered. Further well designed RCTs are needed to investigate the potential of contemporary materials which may be suitable when used in the management of carious teeth. It is recognised that it is difficult to establish the 'ideal' clinical study when ethical approval for new materials must be sought and strict attention to case selection, study protocol and interpretation of data is considered. It is also not easy to recruit sufficient numbers of patients meeting the necessary criteria.

Surgical Endodontics in Dogs: A Review

Surgical endodontic therapy (apical surgery) is a treatment alternative aimed at removing periapical inflammatory tissue followed by apical resection and retro-filling of the root canal. These procedures are performed through a trans-osseous approach. Terminology pertinent to this article include: apical (periapical) curettage – a surgical procedure to remove diseased tissue from the alveolar bone in the apical region of a pulpless tooth; apical cyst – a cyst in bone at the apex of a pulpless tooth. It is believed that such cysts arise after the death of the pulp from noxious physical, chemical, or bacterial stimulation of epithelial rests of Malassez; apicoectomy (apical resection) – amputation of the apical portion of the root and removal of soft tissue in the bone; epithelial rests of Malassez – cords, strands, or clusters of ectodermal cells in the periodontal ligament (or sometimes alveolar bone) derived from remnants of Hertwig's epithelial root sheath. These cells frequently begin proliferating when inflammation occurs in the periodontal ligament and are believed to be responsible for the genesis of the epithelial lining of apical cysts.

[Overall digitalization: leading innovation of endodontics in big data era]

In big data era, digital technologies bring great challenges and opportunities to modern stomatology. The applications of digital technologies, such as cone-beam CT(CBCT), computer aided design,(CAD)and computer aided manufacture(CAM), 3D printing and digital approaches for education , provide new concepts and patterns to the treatment and study of endodontic diseases. This review provides an overview of the application and prospect of commonly used digital technologies in the development of endodontics.

Regenerative endodontics--Creating new horizons

Trauma to the dental pulp, physical or microbiologic, can lead to inflammation of the pulp followed by necrosis. The current treatment modality for such cases is non-surgical root canal treatment. The damaged tissue is extirpated and the root canal system prepared. It is then obturated with an inert material such a gutta percha. In spite of advances in techniques and materials, 10%-15% of the cases may end in failure of treatment. Regenerative endodontics combines principles of endodontics, cell biology, and tissue engineering to provide an ideal treatment for inflamed and necrotic pulp. It utilizes mesenchymal stem cells, growth factors, and organ tissue culture to provide treatment. Potential treatment modalities include induction of blood clot for pulp revascularization, scaffold aided regeneration, and pulp implantation. Although in its infancy, successful treatment of damaged pulp tissue has been performed using principles of regenerative endodontics. This field is dynamic and exciting with the ability to shape the future of endodontics. This article highlights the fundamental concepts, protocol for treatment, and possible avenues for research in regenerative endodontics.

Techniques and materials used by general dentists during endodontic treatment procedures: Findings from The National Dental Practice-Based Research Network

BACKGROUND

Little is known about which materials and techniques general dentists (GDs) use during endodontic procedures. The objectives were to quantify GDs' use of specific endodontic tools, quantify inappropriate use, and ascertain whether inappropriate use is associated with GDs' practice characteristics.

METHODS

GDs in The National Dental Practice-Based Research Network reported in a questionnaire materials and techniques they use during endodontic procedures.

RESULTS

Among eligible GDs, 1,490 (87%) participated. Most (93%; n = 1,383) used sodium hypochlorite to irrigate. The most commonly used sealers were zinc oxide eugenol (43%) and resin (40%), followed by calcium hydroxide (26%). Most (62%; n = 920) used a compaction obturation technique; 36% (n = 534) used a carrier-based method. Most (96%; n = 1,423) used gutta-percha as a filler; 5% used paste fillers. Few used irrigants (n = 46), techniques (n = 49), or fillers (n = 10) that investigators classified as inappropriate.

CONCLUSIONS

GDs use a broad range of endodontic techniques and materials, often adapting to newer technologies as they become available. Few GDs use tools that the investigators classified as inappropriate.

PRACTICAL IMPLICATIONS

GDs use many types of endodontic techniques and materials, but only a small percentage of them are inappropriate.

Patient Demonstration Videos in Predoctoral Endodontic Education: Aspects Perceived as Beneficial by Students

The aim of this study was to assess the perceived benefits of video-mediated demonstrations in learning endodontics. Participants in the study were 75 third-year students enrolled in the undergraduate dentistry program at Karolinska Institute, Stockholm, Sweden. After the endodontic preclinical course, the students were introduced to the treatment protocol in the clinic by watching two live patient-demonstrated videos. The first video demonstrated how to communicate with the patient and perform diagnosis and root canal instrumentation. The second video illustrated how to perform bacterial sampling and root canal filling. After the students watched each video, a questionnaire was used to evaluate their opinions about various steps of the endodontic treatment protocol and the benefit of such educational material for their practice. Of the total 75 students, 72 completed the first questionnaire (96% response rate), and 65 completed the second questionnaire (87% response rate). The results showed that the students perceived high value in the video demonstrations related to treatment procedure. A statistically significant difference was observed between the perceived benefits of the first and second sessions in communication and treatment procedure (p<0.001). Further studies are needed to assess improvement in the design and delivery format for video demonstrations to enhance their effectiveness as a teaching modality for endodontics.

The importance of cone-beam computed tomography in the management of endodontic problems: a review of the literature

INTRODUCTION

To obtain essential information in clinical endodontics, cone-beam computed tomographic (CBCT) imaging can be used in all phases of treatment including diagnosis, treatment planning, during the treatment phase, and through post-treatment assessment and follow-up. The purpose of this article was to review the use of CBCT imaging in the diagnosis, treatment planning, and assessing the outcome of endodontic complications.

METHODS

Literature was selected through a search of PubMed electronic databases for the following keywords: tooth root injuries, tooth root radiography, tooth root perforation, tomography, cone-beam computed tomography, endodontic complications, tooth root internal/external resorption, root fractures, and broken instruments. The research was restricted to articles published in English. One hundred twelve articles met the inclusion criteria and were included in this review.

RESULTS

Currently, intraoral radiography is the imaging technique of choice for the management of endodontic disease, but CBCT imaging appears to have a superior validity and reliability in the management of endodontic diagnosis and complications.

CONCLUSIONS

Endodontic cases should be judged individually, and CBCT imaging should be considered in situations in which information from conventional imaging systems may not yield an adequate amount of information to allow the appropriate management of endodontic problems. CBCT imaging has the potential to become the first choice for endodontic treatment planning and outcome assessment, especially when new scanners with lower radiation doses will be available.

Antenatal and intrapartum risk factors for use of emergency and restorative Medicaid dental services for children

PURPOSE

To investigate the relationship between antenatal/intrapartum factors and Medicaid use.

METHODS

Three databases were used: (1) birth records; (2) Medicaid files; and (3) Medicaid dental claims.

RESULTS

Children of Caucasian mothers were 34 percent more likely to have more than one restorative claim versus children of African American mothers (odds ratio [OR] equals 1.34, 95 percent confidence interval [95% CI] equals 1.10 to 1.65, P<.005). Children born with low birth weight were 37 percent more likely to have emergency claims (OR equals 1.37, 95% CI equals 1.02 to 1.83, P=.03). The adjusted analysis found that Caucasian mothers had higher odds ratio of having a dental claim than African American mothers (P<.001): 33 percent for a restorative claim and 56 percent for an emergency claim. When race was analyzed, the odds of a restorative claim among African American mothers were 2.5 times higher in children delivered by C-section versus those vaginally delivered (OR equals 2.52, 95% CI equals 1.02-6.2, P<.001).

CONCLUSIONS

This study found: an association between children of Caucasian mothers and the likelihood of experiencing claims; and a relationship between children born with low birth weight and C-section and the likelihood of use of Medicaid services.

Radix Entomolaris - a rare case series

INTRODUCTION

The success of root canal treatment is determined by satisfying the basic principles of complete removal of the endodontic pathology through chemo-mechanical cleansing of the root canals followed by shaping and then by obturation to provide the ideal hermetic seal. To achieve such success a thorough knowledge of the root canal anatomy is a basic requirement. Several anatomic variations of the mandibular molars have been reported among which is the reportedly rare Radix Entomolaris(RE), a mandibular molar with an additional root located lingually.

AIMS AND OBJECTIVES

To present five cases of RE diagnosed pre-operatively using radiographs and subsequently successfully endodontically treated. We also aim to highlight the considerations for the diagnosis and management of RE in general dental practice.

CONCLUSION

Even though RE is rarely encountered in general dental practice, the possibility that it may occur warrants the need to have sufficient knowledge regarding diagnosis and the appropriate modifications in endodontic management of these teeth. Preparedness coupled with a carefully modified clinical approach aids in successful management of RE and ensures that these cases could be handled with ease.

Cone beam computed tomography updated technology for endodontic diagnosis

Cone beam computed tomography has gained acceptance in the endodontic community for assistance with diagnosis, treatment, and evaluation of outcomes. This article reviews a multitude of applications, from basic principles to clinical applications, using specific cases and supporting literature to demonstrate the benefits for both the specialist and general practitioner.

[A retrospective study of 693 children's dental treatment under general anesthesia]

OBJECTIVE

To retrospectively analyze the clinical features of children who received dental treatment under general anesthesia (GA) and the characteristics of dental treatment.

METHODS

The records of 693 patients treated under GA in the Department of Pediatric Dentistry, Peking University School and Hospital of Stomatology, between Jan. 2001 and Dec. 2012 were collected and analyzed.

RESULTS

The numbers of patients treated under GA increased year-to-year. Most of them were under 4-year-old. The main reasons of dental treatment under GA were uncooperative and disabled. The average number of teeth treated was 12±4 for each child, and the average time for treating one tooth was 12 min. The 3 months follow-up rate was 60.31%, and the older, the fewer treated tooth number and out-of-town associated with the less follow-up rate.

CONCLUSION

The main reasons of dental treatment under GA are uncooperative and disabled. GA is an effective and safe method for dental rehabilitation in children.

A review of pulp therapy for primary and immature permanent teeth

The aim of pulp therapy in primary and young permanent teeth is to maintain a functional tooth so that arch integrity is preserved in a growing child. History, clinical evaluation and radiographic findings should be integrated to arrive at pulp diagnosis. Vital pulp therapy should be attempted whenever the pulp is diagnosed to be vital. Nonvital pulp therapy should be performed for strategically important primary teeth. Revascularization is an emerging technique for immature necrotic teeth.

Bisphosphonate-related osteonecrosis of the jaws: a potential alternative to drug holidays

In 2011, the American Dental Association Council on Scientific Affairs released an update by their expert panel on managing the care of patients receiving antiresorptive therapy for the prevention and treatment of osteoporosis. In this report, the panel found no study results that confirmed the effectiveness of drug holidays to prevent antiresorptive agent-induced osteonecrosis of the jaws without increasing the risks of low bone mass. The purpose of this article is to provide suggestions for a pattern of patient care for individuals who desire or require an invasive surgical procedure of the jaws, but who also have a skeleton that is at risk for osteoporotic fracture. The authors reviewed pertinent literature related to basic bone histology, the pharmacokinetics of the aminobisphosphonates (nBP), diagnostic criteria for osteopenia/osteoporosis, and clinical applications of the antiresorptive agents. The skeletal system demonstrates a mixture of resting surfaces (osteocytes, 85%), resorbing surfaces (osteoclasts, 2%), and forming surfaces (osteoblasts, 10%-12%). Deposition of nBP is not uniform, and is highly concentrated in areas of bone remodeling. A full understanding of bone remodeling and the pharmacokinetics of nBP allow for the modification of the antiresorptive therapy and the timing of the oral surgical procedure in a manner that minimizes the prevalence of osteonecrosis while at the same time continuing to protect the patient's skeleton from osteoporotic fracture. The lack of support for drug holidays by the ADA's expert panel is strongly consistent with the science behind bone remodeling and nBP pharmacokinetics. In spite of this, creative interdisciplinary patient care has the potential to dramatically reduce the prevalence of bisphosphonate-related osteonecrosis (BRON), while at the same time continuing to protect the skeleton of the osteoporotic patient. Creative interdisciplinary patient care may prove to be an effective intervention to reduce the prevalence of BRON of the jaws.

[Effect of revascularization treatment of immature permanent teeth with endodontic infection]

OBJECTIVE

To observe the effect of revascularization for treatment of immature teeth with endodontic infection mediated by calcium hydroxide.

METHODS

Seventeen pediatric patients with endodontic infections of the permanent teeth were treated with routine root canal and pulp cavity irrigation and disinfection followed by application of calcium hydroxide paste to the root canal orifice to induce revascularization. Another 17 patients received conventional apexification procedures to serve as the control group. The patients were followed up to observe the therapeutic effect of the treatments.

RESULTS

In the revascularization treatment group, 4 cases showed healed periapical lesions 6 to 18 months after the surgery with thickened root canal walls and closure of the apical foramen; in 10 cases, the periapical lesions healed 12 to 18 months postoperatively with lengthened root, thickened root canal wall, and narrowed apical foramen. One patient reported pain and swelling at 2 months, and 2 patients showed the formation of gum fistula and ceased development of the roots at 7 and 8 months. In the control group, the periapical lesions healed in 1 cases at 12 months postoperatively with apical foramen closure; in 11 cases, hard tissues formed in the root apex without obviously lengthened roots 6 to 8 months after the surgery; in 5 cases, no apical barrier formed even 12 to 18 months after the surgery. The overall effective rates were similar between the two groups (P>0.05).

CONCLUSIONS

Revascularization by calcium hydroxide sealing can promote root development of immature permanent teeth with pulpitis or periradicular periodontitis.

Comparison of endotoxin levels found in primary and secondary endodontic infections

INTRODUCTION

This clinical study was conducted to compare the levels of endotoxins (lipopolysaccharides [LPSs]) found in primary and secondary endodontic infections with apical periodontitis by correlating LPS contents with clinical/radiographic findings. In addition, the presence of target gram-negative anaerobic bacteria was also investigated.

METHODS

Samples were taken from 15 root canals with primary infections and 15 with secondary infections by using paper points. The limulus amebocyte lysate assay was used to quantify endotoxins, and the polymerase chain reaction technique (16S rDNA) was used for bacterial investigation.

RESULTS

Endotoxins were detected in 100% of the root canal samples collected from primary (15/15) and secondary (15/15) infections with median values of 7.49 EU/mL and 3.96 EU/mL, respectively (P < .05). The median value of endotoxins found in the presence of clinical symptoms was significantly higher than in asymptomatic teeth with primary infections (P < .05). A positive correlation was found between endotoxin contents and a larger size of the radiolucent area (>3 mm) (P < .05). Prevotella nigrescens (10/15, 4/15), Fusobacterium nucleatum (5/15, 1/15), Treponema denticola (3/15, 1/15), and Treponema socranskii (5/15, 1/15) were detected in teeth with primary and secondary infections, respectively. P. endodontalis was present only in teeth with primary infections (5/15).

CONCLUSIONS

Teeth with primary endodontic infections had higher contents of endotoxins and a more complex gram-negative bacterial community than teeth with secondary infections. Moreover, the levels of endotoxins were related to the severity of bone destruction in periapical tissues as well as the development of clinical features in teeth with primary infections.

Current trends in pulp therapy: a survey analyzing pulpotomy techniques taught in pediatric dental residency programs

PURPOSE

The study's purpose was to survey directors of pediatric dental residency programs in order to evaluate the materials currently being taught and used for pulpotomy procedures for primary teeth in educational and clinical settings.

METHODS

A web-based survey was emailed to all graduate pediatric dental residency program directors in the United States.

RESULTS

Seventy one emails were sent to program directors, 47 responded but only 39 respondents (55%) were included in the study. Results suggested a slight decrease in utilization of formocresol 1:5 dilution (P<.01) and an increase in both ferric sulfate (P<.05) and mineral trioxide aggregate (MTA; P<.02) utilization for primary tooth pulpotomy procedures. The most common reasons for elimination of formocresol (18% of respondents) were systemic health concerns and carcinogenicity, in addition to evidence-based literature. Even though 25% of respondents have begun to use MTA for primary pulpotomy procedures, the most common reason for utilization of other medicaments over MTA was its higher cost.

CONCLUSIONS

With 82% of graduate pediatric dental residency programs still utilizing formocresol 1:5 dilution for pulpotomy procedures in primary teeth, there has been no major shift away from its clinical use, in spite of increased usage of newer medicaments over the last 5 years.

Randomized controlled trial: parental compliance with instructions to remain silent in the dental operatory

PURPOSE

The purposes of this study were to: (1) determine compliance in requesting parents to remain silent (noncommunicative) when accompanying their child into the dental operatory for restorative care; and (2) determine if any difference in parental compliance existed when combined written and verbal instructions were given to a parent vs written instructions only.

METHODS

Thirty-nine parents of 4- to 9-year-olds presenting for restorative care met eligibility criteria for the study. Parents were randomly assigned to a written instructions-only group or a group that received combined written and verbal instructions.

RESULTS

Thirty-two of 39 parents (82%) followed instructions to remain silent. There was no statistical difference in parental compliance to remain silent comparing written instructions (78%) to combined written and verbal instructions (86%).

CONCLUSION

Parents may be expected to comply with instructions to remain silent in the operatory when given either written or combined written and verbal instructions.

Clinical performance of all-ceramic cantilever fixed dental prostheses: results of a 2-year randomized pilot study

OBJECTIVE

To evaluate the clinical performance of zirconia-based cantilever fixed dental prostheses (FDPs).

METHOD AND MATERIALS

Twenty-one cantilever FDPs with three or four units were designed to replace one premolar or incisor (no canines). The FDPs were divided into 11 zirconia cantilever FDPs (test group) and 10 metal-ceramic cantilever FDPs (control group) and randomly assigned to patients. The results documented included failures, complications, plaque accumulation, and esthetic performance. Statistical analysis was performed using the Mann-Whitney U and chi-square tests.

RESULTS

During the 2-year observation period, a total of five clinically relevant complications in four patients occurred: three endodontic problems (two in the test group and one in the control group) and two veneer chippings (both in the test group). Plaque accumulation on the abutment teeth was not significantly different among groups. The esthetic performance of all FDPs was acceptable.

CONCLUSION

Stability and esthetic performance were acceptable for all-ceramic cantilever FDPs fabricated with zirconia. A longer observation period and larger sample size are necessary to make valid predictions about the longevity of these restorations.

A comparison of endodontic treatment outcomes between HIV-positive and HIV-negative patients

INTRODUCTION

There has been some surmise that immunocompromised patients may not be candidates for endodon tic therapy.

AIM

To compare the clinical presentation, treatment, and treatment outcomes of HIV+ve and HIV-ve patients receiving endodontic therapy.

METHOD

Fifty-nine HIV-ve and 46 HIV+ve patients who consented to join the study were sequentially selected from those presenting at the hospital. Clinical features were recorded for pain on palpation and percussion, thermal sensitivity, radiographic appearance, swelling, and time for treatment. Endodontic outcomes were assessed at 6, 12, 18 and 24 months.

RESULTS

There was no statistically significant difference in the presenting signs and symptoms of the two groups, although HIV+ve patients reported more severe pain. HIV+ve patients presented with mainly anterior teeth requiring therapy, but only three teeth (24%) had caries. Active caries was present in 71% (42) of the HIV-ve patients and in only 7% (three) of the HIV +ve patients. Treatment time for comparable teeth in the HIV-ve patients (52 minutes) was nearly half that of the HIV+ve (112 minutes) patients, mainly due to the latter experiencing excessive canal bleeding during treatment. There was no significant difference in the final outcome at 24 months, though resolution of signs and symptoms tended to occur earlier in the HIV-ve patients.

CONCLUSIONS

Endodontic therapy is not contra-indicated HIV+ve patients, although treatment times may be longer, and time to full resolution may take longer in some of these patients. A comparison of endodontic treatment outcomes between HIV positive and HIV negative patients.

Treatment of combined endodontic-periodontic lesions using guided tissue regeneration: clinical case and histology

The aim of this case report is to histologically evaluate periapical healing after combined endodontic-periodontic treatment. A maxillary left central incisor was treated with conventional endodontic therapy, followed by periodontal surgery. The facial bony defect was filled with a mixture of autologous bone and Bio-Oss. A resorbable membrane was used. Histology showed the presence of new cementum, ligament, and bone around the apex of the treated tooth. This finding was clinically associated with minimal residual probing depth and maximum attachment gain. This histologic report demonstrates the possibility of true regeneration in a case of severe periodontal attachment loss resulting from an endodontic-periodontic lesion.

Antibiotic resistance in primary and persistent endodontic infections

INTRODUCTION

The presence of antibiotic resistance genes in endodontic microorganisms might render the infection resistant to common antibiotics. The aims of this project were to identify selected antibiotic resistance genes in primary and persistent endodontic infections and to determine the effectiveness of contemporary endodontic procedures in eliminating bacteria with these genes.

METHODS

In patients undergoing primary endodontic treatment or retreatment, the root canals were aseptically accessed and sampled before endodontic procedures as well as after contemporary chemomechanical preparation and medication with calcium hydroxide. Identification of the following antibiotic resistance genes was performed by using polymerase chain reaction: bla(TEM-1), cfxA, blaZ, tetM, tetW, tetQ, vanA, vanD, and vanE. Limited phenotypic identification and antibiotic susceptibility verification were also performed.

RESULTS

Overall, there were 45 specimens available for analysis, 30 from primary and 15 from persistent endodontic infections. In preoperative specimens, only bla(TEM-1) was significantly more prevalent in primary versus persistent infections (P = .04). After contemporary treatment procedures, there was an overall reduction in prevalence of these genes (P < .001). bla(TEM-1) and tetW were significantly reduced (P < .05), cfxA, blaZ, and tetQ were eliminated, but there was no change in tetM. No specimens contained vanA, vanD, or vanE. Antibiotic susceptibility testing showed significant differences among the antibiotics (P < .001) and general concordance with the gene findings.

CONCLUSIONS

bla(TEM)(-1) was more prevalent in primary than persistent infections. Vancomycin resistance was not present. The genes identified were reduced with treatment except for tetM. Genetic testing might be useful as a screening tool for antibiotic resistance.

Endodontic management of maxillary supplementary premolar using cone-beam computed tomography

Extra teeth in dentition is termed as 'supernumerary teeth' and is a very well-known dental developmental anomaly. Supernumerary premolars are a rare anomaly in the maxillofacial complex. Its rarity and complex characteristics often makes it difficult to treat. Radiographs play an important role in assessment of both the location and the typing of supernumerary teeth. This article reports the rare case of 'nonsyndromic bilateral maxillary supernumerary premolars' in which the endodontic management of supernumerary premolar tooth is described. In this case the value of cone-beam computerized tomography is also emphasized.

CLINICAL SIGNIFICANCE

Developmental anomalies can occur in any tooth and supplementary premolars are no exception. The complexity of such teeth has to be considered for planning endodontic treatment to increase the chances of success.

The microbial challenge to pulp regeneration

Pulp regeneration is considered in cases where the dental pulp has been destroyed because of microbial irritation. Diverse oral and food-borne micro-organisms are able to invade the pulp space, form biofilm on canal walls, and infiltrate dentinal tubules. Prior to pulp regeneration procedures, the pulp space and dentinal walls need to be sufficiently disinfected to allow for and promote regeneration. The necessary level of disinfection is likely higher than that accepted for traditional endodontic therapy, because in traditional techniques the mere lowering of bacterial loads and prevention of bacterial access to periapical tissues is conducive to healing. Moreover, several of the non-specific antimicrobials used in traditional endodontic therapy may cause significant changes in remaining dentin that interfere with its inherent potential to mediate regeneration. Non-specific antimicrobials also suppress all microbial taxa, which may allow residual virulent micro-organisms to preferentially repopulate the pulp space. Therefore, it is important for endodontic pathogens to be studied by molecular methods that allow for a broad depth of coverage. It is then essential to determine the most effective protocols to disinfect the pulp space, with minimal disruption of remaining dentin. These protocols include the topical use of effective antibiotics, including newer agents that have demonstrated efficacy against endodontic pathogens.

Rehabilitation of amelogenesis imperfecta using a reorganized approach: a case report

Amelogenesis imperfecta is a genetic disorder that causes defective enamel development in both the primary and permanent dentitions. Significant tooth structure damage often results in various pulpal symptoms, occlusal disharmony, impaired function, and esthetic disfigurement. These problems pose great challenges to the clinician when rehabilitating patients with amelogenesis imperfecta. This case report describes an uncomplicated and logical way to reorganize, temporize, and completely restore an extensively damaged dentition caused by amelogenesis imperfecta.

"MTA"-an Hydraulic Silicate Cement: review update and setting reaction

OBJECTIVES

To review the current status and understanding of Portland cement-like endodontic materials commonly referred to by the trade designation "MTA" (alias "Mineral Trioxide Aggregate"), and to present an outline setting reaction scheme, hitherto unattempted.

METHOD

The literature was searched using on-line tools, overlapping an earlier substantial review to pick up any omissions, including that in respect of ordinary Portland cement (OPC), with which MTA shares much. The search was conducted for the period January 2005 to December 2009 using 'MTA', 'GMTA', 'WMTA', and 'mineral AND trioxide AND aggregate' as keywords, with various on-line search engines including ScienceDirect (http://www.sciencedirect.com), SAGE Journals Online (http://online.sagepub.com), Wiley Online Library (http://onlinelibrary.wiley.com), SciELO Scientific electronic library online (http://www.scielo.br/scielo.php), JSTOR (http://www.jstor.org), and Scopus (http://www.scopus.com). References of articles found were cross-checked where appropriate for missed publications. Manufacturers' and related websites were searched with Google Search (http://www.google.com.hk).

RESULTS

A generic name for this class of materials, Hydraulic Silicate Cement (HSC), is proposed, and an outline reaction scheme has been deduced. HSC has distinct advantages apparent, including sealing, sterilizing, mineralizing, dentinogenic and osteogenic capacities, which research continues to demonstrate. However, ad hoc modifications have little supporting justification.

SIGNIFICANCE

While HSC has a definite place in dentistry, with few of the drawbacks associated with other materials, some improvements in handling and other properties are highly desirable, as are studies of the mechanisms of the several beneficial physiological effects. Reference to the extensive, but complex, literature on OPC may provide the necessary insight.

The coming era of regenerative endodontics: what an endodontist needs to know

Recently, two new clinical concepts have emerged for the management of endodontically compromised immature permanent teeth. One involves a revitalization approach to achieve tissue generation and regeneration in the root canal system. In this method, new living tissue is expected to form in the cleaned canal space allowing continued root development in terms of both length and thickness. The other is the active pursuit of pulp/dentine regeneration via tissue engineering technology to implant or re-grow pulps. Although the technology is still at its infancy, it has potential to benefit immature pulpless teeth by allowing continued growth and maturation. Evidence has shown that using dental stem cells, pulp and dentin can be regenerated in the root canal space. It is foreseeable that a decade or two from now, regenerative endodontics is likely to be an alternative treatment modality for clinical endodontics. It is therefore important for us to understand stem cells and tissue regeneration and be prepared for this clinical practice.