External root resorption--fact or fancy

A review of external resorption is presented with an emphasis on a wide range of etiological factors. This case report details the possible pitfalls in basing the diagnosis solely on radiographic interpretation.     

Monoblocks in root canals: a hypothetical or a tangible goal

The term monoblock has become familiar in the endodontic literature with recent interest in the application of dentin adhesive technology to endodontics. Endodontic monoblocks have generated controversial discussions among academicians and clinicians as to whether they are able to improve the quality of seal in root fillings and to strengthen roots. This review attempts to provide a broader meaning to the term monoblock and to see how this definition may be applied to the materials that have been used in the past and present for rehabilitation of the root canal space. The potential of currently available bondable materials to achieve mechanically homogeneous units with root dentin is then discussed in relation to the classical concept in which the term monoblock was first employed in restorative dentistry and subsequently in endodontics.     

Periodontal repair in dogs: effect of root surface treatment with stannous fluoride or citric acid on root resorption

This study evaluated healing, with emphasis on root resorption, following root surface treatment with 1% aqueous stannous fluoride (SnF2), saturated citric acid (CA), or saline control (C) in conjunction with periodontal flap surgery. Supraalveolar periodontal defects were surgically created and immediately treated in the mandibular premolars in 6 beagle dogs. The defect height approximated 5 to 6 mm from the reduced alveolar bone to the cemento-enamel junction. Root treatments were rotated between experimental teeth within jaw quadrants and duplicated in left and right quadrants in the dogs. Flaps were raised to cover most of the crowns of the teeth and sutured. The dogs were sacrificed 12 weeks after surgery and tissue blocks with teeth and adjacent structures were processed for histometric analysis. SnF2-treated teeth healed with significantly longer junctional epithelium, less connective tissue repair to the root surface, and less bone regeneration than CA and C-treated teeth. New cementum formation was limited in all treatment groups. Root resorption was observed in almost all teeth exhibiting connective tissue repair, however to a lesser amount and not as frequent in SnF2 treated teeth due to limited connective tissue repair. No differences were found in amount and frequency of root resorption in CA and C-treated teeth. An inhibitory effect on root resorption of SnF2 could not be disclosed in this experiment, however, it may be concluded that CA treatment of the root surface in conjunction with reconstructive periodontal flap surgery does not seem to enhance root resorption.     

Root cleaning or root smoothing An in vivo study

Abstract The goal of the present study was to determine whether the clinical treatment results in terms of pocket probing depth reduction and attachment gain would be different following conventional periodontal flap surgery if, on the one hand, root surfaces were smoothed after plaque and calculus removal or, on the other hand, root surfaces were first thoroughly cleaned but then intentionally roughened. 13 adult patients with moderate periodontitis participated: the same patients acted as a unit of control. Evaluations were performed on a total of 224 sites on 81 anterior and premolar teeth. On the 41 test teeth (111 sites). a coarse diamond stone was used following traditional root planing to roughen the root surfaces. The 40 control teeth (113 sites) were cleaned and planed using Gracey curettes. Measurements performed 3 and 6 months post-surgery revealed significant reductions in probing depths at both “rough” and “smooth” sites. However, no differences between the 2 methods were detected. This was true also with regard to attachment gain. We conclude that striving for root surface smoothness during periodontal surgery appears unnecessary.     

单根管与多根管铸造桩核用于磨牙残冠修复的比较研究

目的比较单根管与多根管铸造桩核冠修复磨牙残冠的临床效果。方法选择140例患者的153颗磨牙残冠,在修复前行完善的根管治疗,其中92颗采用单根管整体铸造桩核冠修复,61颗采用插销式铸造的多根管桩核冠修复。对修复后两年的复查结果进行临床效果评价。结果单根管固位修复体桩核松动1个,其余桩核X线片显示桩核与根管结合紧密,修复效果良好。多根管分体插销式铸造桩核冠无松动。修复的临床效果无显著性差异(P>0.05)。结论采用单根管铸造桩核修复磨牙残冠不仅制作简单,而且与多根管分体桩核修复无显著性差异,同样可取得良好的临床效果。     

Intermittent or continuous ultrasonically activated irrigation: micro-computed tomographic evaluation of root canal system cleaning

Objectives

The aim of this study was to evaluate the efficacy of two passive ultrasonic irrigation (PUI) methods and conventional manual irrigation (CMI) in root canal system (RCS) cleaning.

Materials and methods

Artificial single-rooted teeth were used. Four lateral canals were made 2 and 7 mm short from the apex. Root canals were filled with a contrast solution. The specimens were divided into four groups (n = 8): PUI1—intermittent flushing; PUI2—continuous flushing; CMI1—at 1 mm; and CMI2—at 3 mm. Micro-computed tomographic images were obtained. New images were taken after the irrigation protocols enabling the evaluation of the contrast solution volume (in mm³) within RCS (main and lateral root canals) in comparison to the initial analysis. The comparison among groups was performed using ANOVA and Tukey’s tests with 5 % significance level.

Results

There was no difference among PUI1, PUI2, and CMI1 regarding the contrast solution removal from RCS (p > 0.05). These methods demonstrated greater cleaning than CMI2. At the apical third, CMI2 showed lower cleaning capacity when compared to the other methods (p < 0.05).

Conclusions

PUI with intermittent or continuous flushing and CMI with the needle placed 1 mm from the working length were efficient in cleaning the main and lateral root canals.

Clinical relevance

Root canal irrigation plays an important role in cleaning and disinfection of the RCS. Effective apical irrigation is an important procedure during root canal treatment. PUI and CMI (at 1 mm short) were effective in cleaning of the main and simulated lateral root canals.

     

老年患者细小钙化根管的临床治疗

目的:探讨老年患者细小钙化根管的治疗方法和临床疗效.方法:选取老年患者中有细小或钙化根管的患牙65颗,采用乙二胺四乙酸(EDTA)溶液和小号手用K锉疏通细小根管,超声锉与EDTA、小号手用锉结合处理钙化根管,完成根管治疗并观察疗效.结果:59颗患牙的根管疏通成功并完成根管治疗,成功率为90.8%,细小根管疏通成功率为100.0%,钙化根管再通成功率为81.3%.无牙根折裂、台阶形成、根管壁侧穿或器械折断发生.结论:超声器械、EDTA、小号手用K锉相结合,可作为临床上治疗老年患者细小钙化根管的有效方法,但超声器械不宜用于根管的下段或弯曲部位.     

Characterization of root surface periodontal ligament following avulsion, severe intrusion or extraction: preliminary observations

Abstract –  This study employed novel topographic and histological techniques to assess remaining periodontal ligament (PDL) in a convenience sample of avulsed and intruded human permanent incisors and extracted premolars. Seventeen human teeth (eight avulsed, five severely intruded and four uninjured extracted) were evaluated for the distribution and physical characteristics of adherent root surface PDL. The topographic distribution of PDL was assessed by staining roots with malachite green and determining the proportion of remaining PDL within selected regions on four aspects of each tooth. In order to characterize mechanical damage to PDL, serial transverse sections of roots were stained with hematoxylin and eosin and examined at magnifications of 40× to 800×. The sections were photographed and imaging software was used to calculate the percentage of remaining PDL in the circumference of each root section. Topographic analysis demonstrated that 54% of the PDL remained on roots of avulsed and severely intruded incisors and 36% of the PDL remained on the extracted single-rooted premolars. Examination of serial transverse root sections revealed that 58% of the PDL remained on roots of avulsed or severely intruded incisors and 54% on extracted premolars. Avulsed and severely intruded incisors demonstrated similar amounts of retained PDL. In both injuries, almost half of the root surface was denuded of PDL.     

Reasons for dentists' acceptance or rejection of microbiological root canal sampling

Microbiological root canal sampling (MRS) has been found to be used by only a few Swedish general dentists. The present study addresses the reasons for their acceptance or rejection of the technology. A questionnaire was mailed to 240 general dentists practising within the city of Goteborg. The questionnaire concerned certain practice characteristics and attitudes to MRS. The data showed that MRS is mainly performed by dentists working with adult patients in private practice. The technology is rarely used routinely, but is applied in selected cases. The main reason for non-adoption seems to be a perceived lack of relative advantage over conventional treatment strategies. Furthermore, opinions regarding the complexity and observability of the technology appear to influence acceptance significantly.     

Vital pulpectomy and root filling with N2 or Endomethasone

Summary. Using an aseptic and standardized endodontic technique, vital pulpectomy was performed on 16 pairs of human permanent maxillary front teeth scheduled for extraction in connection with prosthetic treatment. All the teeth had clinically sound pulps before treatment and 16 teeth were root filled with N2 and the other 16 with Endomethasone. In all cases except two, contralateral teeth were used. After 4–8 months the teeth were extracted and processed for histological examination using light microscopy. Histological examination of the residual pulp demonstrated no statistically significant differences between the two root-filling materials, concerning inflammation and the frequency of necrosis. The healing reactions, occurrence of fibrous tissue in the residual pulp and hard tissue apposition on the root canal wall, were more pronounced after root filling with N2, than after Endomethasone, but the differences were not statistically significant. Comparing the results with those after vital pulpectomy and root filling with zinc oxide-eugenol cement, total necrosis of the residual pulp was most frequent after root filling with Endomethasone, less so after zinc oxide- eugenol cement and least after root filling with N2, but the differences were not statistically significant. When estimated from the local findings, that is the histological reactions in the residual pulp, no advantages could be observed by using N2 or Endomethasone, and owing to the risk of general side effects, because of the formaldehyde content and the complex composition of the two materials routine use of N2 or Endomethasone cannot be recommended in pulpectomy.     

Periosteal connective tissue grafting or root coverage with enamel matrix derivative: a case report

A 24-year-old female patient presented for the resolution of esthetic concerns associated with wide gingival recession facial to the maxillary left central incisor before orthodontic treatment. A periosteal connective tissue graft in conjunction with an enamel matrix derivative was used to achieve root coverage. This technique achieved healthy thick keratinized tissue coverage of the root surfaces and effectively improved the esthetics. These satisfactory clinical results have been maintained for 18 months, even through active orthodontic treatment.
CLINICAL SIGNIFICANCE
This case report demonstrates an innovative approach to root coverage that uses an enamel matrix derivative in conjunction with periosteal connective tissue grafting. Although there is no absolute clinical evidence that the enamel matrix derivative contributed to the final outcome, the results are encouraging and should be pursued through case-controlled clinical trials.