Current practice in endodontics: 3. Access is success, and rubber dam is easy

The prime aim of this series of articles is to improve the quality of endodontic treatment in general dental practice by considering what is currently being taught in dental schools. This, the third article, offers guidance and hints to ease the use of rubber dam, which should be mandatory for root canal therapy. It also considers the shape, position and extent of access cavities. The access cavity can make all the difference in success or failure of endodontic treatment.     

Current practice in endodontics: 6. Retreatments and periradicular surgery

The prime aim of this series of six articles has been to improve the quality of endodontic treatment in general dental practice by considering what is currently being taught in dental schools. This final article considers what may go wrong following completion of root canal treatment, whether orthograde retreatment is possible and how it may be achieved, and if or when periradicular surgery may be indicated.     

Current practice in endodontics

The aim of this series of six articles is to improve the quality of endodontic treatment in general dental practice by considering what is currently being taught in dental schools. This first article considers the rationale behind endodontic treatment, what we are aiming to achieve and why. It looks at the dental and medico-legal issues which dictate the standards of our practice, and sets out the programme for the series.     

Current practice in endodontics: 4. A review of techniques for canal preparation

The prime aim of this series is to improve the quality of endodontic treatment in general dental practice by considering what is currently being taught in dental schools. This article reviews the development of today's endodontic techniques and suggests alternative methods of obtaining a clean and shaped canal, in keeping with the varying requirements of practitioners of differing backgrounds and abilities, while keeping in mind the established aims and objectives of endodontic treatment.     

Current practice in endodontics: 5. Obturation

The aim of this series of six articles is to improve the quality of endodontic treatment in general dental practice by considering what is currently being taught in dental schools. This article first considers the possible reasons for persisting symptoms following preparation of the root canals. It then reviews the many and varied methods of obturating the prepared root canal system that are available to the general dental practitioner. By considering the objectives of their treatment, and their own level of expertise, readers may decide that one or more new techniques may benefit their practice.     

Current practice in endodontics: 2. Diagnosis and treatment planning

The aim of this series of six articles is to improve the quality of endodontic treatment in general dental practice by considering what is currently being taught in dental schools. This second article considers the accurate diagnosis of endodontic lesions, which frequently present as emergencies requiring prompt, rapid and efficient attention. The paper then presents the treatment normally indicated once a correct and accurate diagnosis has been made.     

The smear layer in endodontics

With the cascade of new restorative products being unveiled almost monthly, dentists incorporating endodontics into their practices must be able to evaluate the potential of these products for successful integration into their procedures. This evaluation should be based on a knowledge of how the new products relate to the smear layer formed along the root canal walls. Rather than relying on information supplied by the dental manufacturers, the aware dentist should regularly resort to the most current research reports available in journal or abstract form. With the use of certain products in some clinical situations, other branches of restorative dentistry may suggest retention of the smear layer. Although pulpally infected teeth have been successfully treated for generations in the presence of the smear layer, it has become accepted practice now in endodontics to remove the smear layer. Different quantities and qualities of smear layer can be produced by various techniques of instrumentation. However, they all present a barrier to intimate contact between obturating materials and the canal wall. Various types of solvents will produce different results in smear layer removal. One ideal endodontic irrigant follows the use of the antimicrobial 5.25 per cent sodium hypochlorite solution with the equally antimicrobial 6 per cent citric acid solution or 17 per cent EDTA. Chelating agents are effective in that they remove the smear layer, open the dentinal tubules, and produce a clean surface for closer obturation. Removal of the smear layer encourages the creation of a good apical plug to prevent over filling, post-filling sensitivity, and possible microleakage. The use of glass ionomer cements and unfilled resin as a cementing medium following smear layer removal shows promising results in both strength of cementation and the possibility of reducing post lengths. Controversies will always arise in dentistry with the advent of new information and the discovery of new clinical techniques. But a total awareness of both sides of a controversy will enable the practitioner to find a way through the confusion.     

The removal of the smear layer using EGTA: a scanning electron microscopic study

The smear layer associated with endodontic instrumentation is currently thought to be a thin layer that occludes the orifices of the dentinal tubules and covers the intertubular dentin of the prepared canal wall. The purpose of this study was to compare the effect of ethylene glycol bis (beta-amino ethyl ether)-N, N, N', N'-tetra acetic acid (EGTA) and ethylene diamine tetra acetic acid (EDTA) on removal of the smear layer through the scanning electron microscopy. Twenty four single rooted teeth were selected, instrumented and irrigated with various solutions and the specimens were processed for scanning electron microscopy. It was found that though both EGTA and EDTA completely removed the smear layer, EDTA caused erosion and conjugation of the tubules, whereas, EGTA effectively removed the smear layer without inducing any erosion. It was thus concluded that EGTA can be effectively used as an alternative chelator for the removal of the smear layer.     

Teaching students the repair of resin-based composite restorations: a survey of North American dental schools

BACKGROUND: The purpose of this study was to evaluate whether North American dental schools teach students to repair resin-based composite, or RBC, restorations and to compare the findings with those from similar European surveys. MATERIALS AND METHODS: The authors mailed a 15-item questionnaire to 64 dental schools in the United States, Canada and Puerto Rico. The survey asked whether the school taught repair of RBC restorations and inquired about the respondent's experience with such procedures. Questions also elicited reasons why schools taught or did not teach repair, information in regard to relevant decision-making processes, criteria for deciding whether to perform repairs and the nature of the instruction (theoretical, practical, preclinical or clinical). RESULTS: Fifty-two (81 percent) of 64 schools participated in the survey. Thirty-seven (71 percent) of the respondents reported that they taught undergraduate students repair techniques as an alternative to replacing failing RBC restorations. Twenty-seven (73 percent) of these 37 schools reported that such teaching was at the clinical level, while only three schools (8 percent) reported that it was included in formal lectures as part of preclinical courses. The major reasons given for teaching students how to repair RBC restorations were tooth structure preservation and reduction of potentially harmful effects on the pulp. Indications included the correction of marginal defect and marginal discoloration. CONCLUSIONS: More than one-half of the respondents reported that they taught repair of RBC restorations and that patients were willing to accept such treatment. Most schools considered the repair of RBC restorations to be a definitive measure and reported that, on average, expected a repaired RBC restoration to have a longevity of four years.     

Endodontic materials

This article presents a review of materials currently used in the practice of endodontics. Current endodontic materials include those that have been thoroughly tested by scientific investigation, clinical usage, and time, as well as others that are the result of new knowledge in the field of dental materials. Article sections are devoted to obturation materials, sealers, irrigation materials, smear layer removal, root-end filling materials, and intracanal medicaments. Knowing the particular qualities of materials can aid the clinician in choosing those that are appropriate for a given situation. Properties, components, and rationale for the materials' use are presented to aid the clinician in choosing materials for a particular need.     

Instruction in dental curricula to identify and assist domestic violence victims

Since most domestic violence injuries occur in the head and neck areas, it is critical that dental professionals be prepared to identify, interview, and assist potential victims. The purposes of these surveys in 1996 and 2007 were to investigate U.S. and Canadian dental school curricula regarding the inclusion of domestic violence topics, determine the topics emphasized, determine beliefs of course directors about domestic violence issues, and report progress of dental curricula in preparing dental professionals regarding domestic violence over the eleven-year period. Surveys were sent to associate deans for academic affairs of dental schools in the United States and Canada in 1996 (N=64) and the United States in 2007 (N=56). Each academic dean was asked to forward the survey to the faculty member who taught this topic. Topics most frequently included and emphasized in dental school curricula were the responsibility of the health care professional (HCP) regarding domestic violence, how to identify physical and behavioral indicators, and how to refer the abused victim. The topics least frequently included and emphasized in the curricula regarded education of the abused and the impact of domestic violence on society. There were four strong beliefs reported by dental course directors: a trusting, professional rapport is essential for disclosure; the dentist or a dental team member may be the first HCP to recognize signs of abuse; the dentist has a professional responsibility to refer for assistance; and domestic violence education should be included in dental curricula. Over the eleven years, the surveys demonstrate that course directors have become more aware of the need to inform dental students about domestic violence and that more schools have increased the amount of information about domestic violence in dental courses. However, due to the complexity and sensitivity of this topic, course instructors in dental schools may consider other teaching methods to enhance learning. The authors identified the need for further course development and make recommendations to use experiential learning to enhance dental students' interpersonal and interviewing skills. These strategies may increase dentists' comfort and confidence when treating and assisting possible victims of domestic violence.     

Quality of obturation in student cases instructed by endodontic versus general dentistry faculty.

Endodontic literature suggests that only about 60% of endodontic therapy meets current technical standards and that general dentists may be making a significant contribution to this compromised care. If so, where in the continuum of dental education does this begin. This study evaluated the quality of obturation in mandibular molars provided on the one hand by 3rd year dental students instructed by endodontic faculty, and on the other hand by 4th year students instructed by general dentistry faculty, versus the quality of obturation achieved by endodontic residents who served as a control for both groups. Final radiographs were chosen from students in all three groups so that there were 22 samples per group. Three evaluators rank-ordered the radiographs. In order of excellence, the results were: (a) residents, (b) 3rd year students, and (c) 4th year students. There was no significant difference between the 3rd year students or the residents, only between residents and 4th year students (p < 0.05). The reasons for this outcome may range from dental school objectives to the private practice procedures of the general dentists who instructed the 4th year students.     

3�ַ���ȥȣ�����������۲�ɨ��羵�۲�

目的应用扫描电镜观察传统高速牙钻法、空气喷砂法、CarisolvTM化学机械法去龋后牙本质表面玷污层,肉眼观察窝洞洞底表面。方法将2006年3月至2006年6月南昌大学附属口腔医院收集的新近拔除伴中度龋坏的15颗患牙,依据去龋方法的不同分为3组:传统高速牙钻组、空气喷砂组和CarisolvTM化学机械组。去龋后肉眼观察窝洞洞底表面,并用扫描电镜对牙本质表面玷污层进行观察。结果3种方法均可有效去龋。传统高速牙钻组去龋后窝洞洞底牙本质表面平整、光亮而且透明;空气喷砂组牙本质表面粗糙、凹凸不平;CarisolvTM化学机械组牙本质表面光泽较暗。扫描电镜下观察,CarisolvTM化学机械组去龋后牙本质小管附近玷污层少,牙本质小管栓塞率仅为4.4%,明显低于其他2组(P均<0.05);空气喷砂组牙本质小管清晰可见,周围玷污层仅有少量分布;传统高速牙钻组牙本质小管清晰度较差,周围玷污层大量分布,牙本质小管栓塞率明显高于其他2组(P均<0.05)。结论CarisolvTM化学机械法能有效去龋,清除牙本质玷污层。     

Trends in the placement of posterior composites in dental schools

The aim of this paper is to review trends in the teaching of posterior composites in the United States, Canada, Ireland, and the United Kingdom over the last fifteen years. The authors compared the results of surveys of the teaching of posterior composites performed in 1989, 1997, and 2004-05. Historical and contemporary international trends were investigated. The amount of clinical and didactic teaching of posterior composites has increased over the past fifteen years. From a time over fifteen years ago, when very few dental students placed posterior composites in dental school, approximately one-third of posterior plastic restorations placed by U.S., Irish, and UK dental students are now composite, with the corresponding finding for Canadian dental schools being approximately 50 percent. Some variations were noted between dental schools in terms of the teaching of contraindications to placement as well as lining and basing techniques. There was some inappropriate teaching of techniques, in particular, in relation to the use of transparent matrix bands and light transmitting wedges. There was also evidence of limited student exposure to newer forms of technology, notably LED curing light units. There have been clear increases in the teaching of posterior composites in the United States, Canada, the United Kingdom, and Ireland in recent years; however, the proportion of posterior composite restorations placed by dental students relative to dental amalgams does not yet match the typical situation in contemporary clinical practice. Dental schools have a responsibility to ensure that their curricula are evidence-based to best prepare their students to meet the needs and expectations of their future patients.     

Endodontic dowel retention with resinous cements.

This study compared the capability of three composite resin cements to sustain a standard endodontic dowel. All of the systems incorporated some form of smear layer removal on the dentin of the endodontic channel. One system that used a methyl ethyl ketone drying agent provided inadequate clinical resistance to dislodgment of 5.4 DaN. A second cementing system that used only smear layer removal resisted loads at 54.7 DaN. The third cementing regimen that included a surface-initiated dentinal adhesive and smear layer removal recorded retention of 77.4 DaN. This study supported the concept that passively cemented dowels with composite resin can be as effective as actively seated dowels.     

The teaching of geriatric dentistry in Canada.

Very little is known about the current status of geriatric training programs at Canadian universities because of the scarcity of information published on the subject. A study of the geriatric dentistry training programs offered by Canada's 10 dental schools has been completed. Its intent was to determine what type of educational activities in geriatric dentistry have either been offered in the past, are being offered now, will be offered in the next academic year, or are planned for the next five years. The results indicate that the 10 schools are doing very little in this regard. To keep pace with the level of geriatric dentistry training currently being offered in the United States, the dental profession must convince Canadian faculty members that the teaching of geriatric dentistry is crucial to both the undergraduate student and the graduate dentist. Continuing education in geriatric dentistry could be used to meet the oral health needs of our frail and dependent senior citizens. Geriatric dentistry must be taught at all levels of the profession so that this special clientele can receive the necessary treatment either within or outside of the dental office.     

五倍子水提取物去除根管内玷污层的扫描电镜观察

目的:观察五倍子对根管内玷污层的去除效果。方法:72个离体单根牙随机分为9组,冲洗液为五倍子组(分别为200、100、50、25、12.5、6.25mg/mL)、30mL/L过氧化氢液加生理盐水组、170g/LEDTA加52.5g/LNaOCl组(阳性对照)、双蒸水组(阴性对照)。根管预备后用各冲洗液冲洗,选根中部分进行扫描电镜观察。样本分为10个区,分别评分,结果进行统计学分析。结果:170g/LEDTA加52.5g/LNaOCl组去除玷污层效果最好,但管周牙本质有过度脱矿现象。25、50、100、200mg/mL五倍子组去除玷污层的效果较好,其去除玷污层的能力随浓度增加而增大,且牙本质小管有缩小的现象,当大于50mg/mL时牙本质小管被堵塞。30mL/L过氧化氢液加生理盐水组和双蒸水组不能去除玷污层。结论:大于6.25mg/mL的五倍子水提取物有去除玷污层的作用,随浓度增大,牙本质小管缩小并出现堵塞。     

Perceptions of dental aesthetics in the United States and Nigeria

The standard dental aesthetic index (DAI) is an orthodontic treatment need index based on perceptions of dental aesthetics in the United States. It is a regression equation that links perceptions of the social acceptability of dental aesthetics with the objective intraoral measurements of ten occlusal traits. For the index to be universally acceptable, the perceptions of dental aesthetics in other countries must be similar to those of the United States. This study was designed to determine whether the perceptions of dental aesthetics of Nigerian students are similar to those of different groups of the US population. The same 25 stimuli (photographs of dental configurations, a subset of the 200 stimuli used in deriving the standard DAI equation) were rated for dental aesthetics by Nigerian students. Their ratings were compared with ratings of the same 25 stimuli by US parents, students and orthodontists. Spearman rank-order correlations ranged from 0.75 to 0.84. These correlations were highly significant ( P < 0.0001), and showed that the perceptions of dental aesthetics of Nigerian students were very similar to those of the US groups. The study therefore concluded that standard DAI could be used as a screening tool and without modification in epidemiological surveys among Nigerians.     

Retention of teeth versus extraction and implant placement: treatment preferences of dental faculty and dental students

The purpose of this study was to determine the treatment preferences amongst dental faculty and dental students for either retention of teeth by endodontic and restorative treatment or extraction and implant placement. A survey of 134 general dentistry faculty and 253 senior (fourth-year) dental students was conducted in a university college of dentistry. Participants completed a survey consisting of questions for which one of two choices could be selected. For questions describing specific clinical situations, dental faculty and dental students more frequently selected endodontic and restorative treatment over extraction and implant placement. However, dental students selected implants more frequently than dental faculty, and more recent graduates on the dental faculty selected implants more frequently than less recent graduates on the dental faculty. In addition, there was an increase in the selection of implants, for all participant groups, as the prosthetic and endodontic complexities of the clinical situations increased. Participants were more likely to select endodontics rather than implants for medically compromised patients, and an implant was overwhelmingly selected over a fixed bridge for the replacement of a single tooth unit. In conclusion, the findings of this study indicate that retention of teeth is preferred, but there may be an increased preference toward implants in the future.