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Background: The vibrations created by post‐space preparation during the first visit for endodontic treatment could have a significant effect on the intensity of post‐operative pain than that association with post‐space preparation at the second appointment. Objective: The aim of this study was to evaluate the effect of vibrations generated during post‐installation, on post‐operative pain in endodontically treated teeth. Methods: One hundred patients with asymptomatic teeth requiring primary root canal treatment and post‐installation were enrolled in this study. Fifty patients underwent endodontic treatment with post‐installation at the first visit (group 1), while the remaining 50 patients underwent post‐installation at the second visit (group 2). The intensity of post‐operative pain in both groups was evaluated 1, 2, 3 days and 1 week after the first visit using the visual analogue scale. The time required to achieve complete pain relief for each patient was also recorded. The patients' age, sex, tooth type, size of the periapical lesion and time required for complete post‐operative pain relief for each tooth were recorded. Results: The pain intensity score was significantly higher in group 1 than group 2 (P <.05). No significant differences were observed in parameters such as sex, tooth type, jaw and size of the periapical lesion (P >.05), whereas age had a significant effect on the post‐operative pain scores (P <.05). Conclusion: Vibrations occurring during post‐installation on the same visit as that of root canal filling may increase the post‐operative pain. [ABSTRACT FROM AUTHOR]

Objectives: Pain management during endodontic therapy is an important issue in clinical practice. The objective of this systematic review and meta‐analysis was to evaluate the efficacy of occlusal reduction to control the post‐operative endodontic pain in adults undergoing root canal therapy. Materials and methods: Electronic database and manual searches of English papers were conducted up to August 2019 to identify randomised placebo‐controlled trials. The MeSH terms used were (endodontics OR root canal therapy) AND (postoperative pain) AND (occlusal reduction). The primary outcome measure was the post‐operative pain intensity up to 72 hours. Pooled standardised mean differences (SMDs) and 95% confidence intervals (CIs) were calculated using random‐effects inverse variance method. The statistical heterogeneity was assessed using the Cochrane Q test. The significance level was set at P <.05. Results: In total, six randomised controlled trials including 344 participants were included. Our meta‐analyses showed that relief of occlusal surface did not significantly reduce the pain intensity scores at 12‐ (SMD = −0.46; 95% CI = −1.24, 0.30; P =.239), 24‐ (SMD = −0.17; 95% CI = −0.73, 0.38; P =.533) and 48‐ (SMD = −0.67; 95% CI = −1.38, 0.03; P =.063) when compared to placebo. However, at 72 hours, patients received intervention showed significant more pain reduction than placebo groups (SMD = −1.07; 95% CI = −1.81, −0.32; P =.005). Conclusion: Based on this meta‐analysis, the efficacy of occlusal reduction in post‐endodontic pain control for up to 2 days is not supported. However, on day three, it had a positive influence on the control of post‐endodontic pain. [ABSTRACT FROM AUTHOR]

There is a paucity of guidelines for the dental profession to assess failure of endodontic therapy. While a successful treatment can be well defined by the absence of apical periodontitis and clinical symptoms after a period of observation, failed treatment has escaped a distinct standing over the years. This article highlights aspects of significance and concludes that research ought to better explore the general health properties of persistent apical periodontitis on root-filled teeth and finally confirm the extent there is an association between apical periodontitis and adverse systemic health effects. Clearing this condition will determine whether clinicians should take a serious or relaxed attitude to persistent apical periodontitis subsequent to endodontic treatment. [ABSTRACT FROM AUTHOR]

Deciding whether to replace or preserve a compromised tooth, even with emerging trends in implant dentistry, is still a common dilemma for practitioners. This study sought to determine the 3- to more than 10-year survival rate of teeth that had undergone endodontic, periodontal and prosthodontic treatments. A total of 245 teeth in 87 patients were clinically and radiographically evaluated. All the teeth had received crown lengthening surgery by a single periodontist. Root canal therapy and prosthodontic procedures were rendered either by specialists or by experienced general dentists. Numbers of lost teeth were recorded and the criteria for hopeless teeth were defined. Survival rate was determined using the Kaplan-Meier estimator. Clinical indices including pocket depth ( PD), bleeding index ( BI), C/R ratio, position of the restoration margin relative to the gingival margin ( RM- GM) and the presence of intra-canal post were compared between different survival groups (<3, 3-5, 5-10 and >10 years) using one-way analysis of variance ( anova). Potential predictors of failure were determined using the Cox regression model. The mean ± s.d. of 3-, 5-, 10- and 13-year survival rates was 98 ± 1%, 96 ± 1·6%, 83·1 ± 4·5% and 51·9 ± 14·5%, respectively. The mean PD ( P < 0·013), as well as C/R ratio in the mesial ( P = 0·003) and distal ( P = 0·007) surfaces, was significantly higher in the >10-year-survived teeth. Bleeding index and RM- GM showed no significant differences between the groups. C/R ratio and RM- GM position appeared to be the major determinants of tooth loss. The long-term survival rate of multidisciplinary-treated teeth was 83-98% in this specific sample. [ABSTRACT FROM AUTHOR]

Summary This review aims to explore whether 3D imaging offers an added value in diagnosis of odontogenic sinusitis. Odontogenic maxillary sinusitis accounts for approximately 10-12% of maxillary sinusitis cases. Proper diagnosis of odontogenic sinusitis is based on a thorough dental and medical examination and crucial to ensure therapeutic efficacy. To establish the odontogenic cause of maxillary sinusitis, 2D and 3D imaging modalities may be considered, each presenting distinct advantages and drawbacks. The available research indicates that 2D imaging modalities may often mask the origin of odontogenic maxillary sinusitis. This limitation is particularly evident in the maxillary molar region, stressing the need for 3D cross-sectional imaging. The advent of low-dose cone beam computed tomography in dentistry may be particularly useful when odontogenic maxillary sinusitis is not responsive to therapy. Yet, it seems that more research is needed to validate its use in odontogenic maxillary sinusitis. [ABSTRACT FROM AUTHOR]

This study explored the nature of the unprompted information that clinicians seek before making a treatment decision and whether this decision corresponded with the clinical parameters of the case. Interns, general practitioners (GP) and prosthodontists ( n = 70, mean age 33 years, range 23–68) were presented with a written vignette of partial edentulism that included two spaces and were invited to ask any questions for the purpose of making a treatment recommendation. A list of 48 potential question/answer items was available to the interviewer, of which 38 were asked. These were then allotted to four thematic categories. Mean number of questions asked did not differ significantly amongst groups, although prosthodontists asked significantly more questions in the ‘clinical and radiographic information’ category than GPs ( P = 0·0001) and interns ( P = 0·003). The relationship between a prescribed treatment and questions asked was tested by dichotomizing all recommendations into ‘possible’ or ‘not possible’ based on the authors’ knowledge of the actual case history. There were no significant differences amongst the groups in the frequency of prescribing ‘possible’ treatment (Pearson chi-square 0·083 and 0·108 for upper and lower spaces, respectively), but those who prescribed ‘possible’ treatment asked significantly more questions in the ‘clinical and radiographic information’ category, specifically about bone adequacy in the edentulous areas: upper jaw ( P = 0·0001) and lower jaw ( P = 0·003). It may be concluded that prosthodontists generally opted for more ‘possible’ treatments, as well as seeking items of information that seemed to improve the chance of making recommendations that conformed to the actual case characteristics. [ABSTRACT FROM AUTHOR]

Traditionally, using a long post can cause progressive removal of the root structure, complicate the ability to re-treat the tooth if necessary and make it difficult to apply an adhesive bonding agent into the root canal. It is unclear if a shorter post length can be applied when a light translucent glass fibre post and adhesive resin cement are used. The aim of this study was to evaluate the biomechanical performance of endodontically treated teeth restored with three post materials, glass-fibre, stainless steel and cast-nickel chromium posts and cores of different lengths of 7, 10 and 13 mm. A 3D finite element analysis model of the maxillary central incisor was constructed. An occlusal load of 300 N was applied to a node at the palatal surface of the crown at 45° to the long axis of the tooth. von Mises stress analyses were carried out in three regions. Simulated data were collected for plotting various pattern graphics and conducting statistical tests. The pattern graphics showed that when the post length changed from 13 to 7 mm, the stress patterns were even and flat in all fibre-post groups, while the stress patterns of the metal-post groups showed an M-shaped peak and trough. Statistical tests showed that the shorter fibre post was superior to the longer metal post in some situations. Within the limitations of this study, it was concluded that when a metal post is used, the post should be as long as possible, while the biomechanical performance of a glass-fibre post combined with a composite resin core was less sensitive to post length. [ABSTRACT FROM AUTHOR]

The aim of this study was to assess the influence of the shape of custom cast dowel and cores on their removal by the use of ultrasound technique. Twenty-four single-rooted bovine teeth were prepared and had cast dowel fixed with zinc phosphate cement. The teeth were randomly divided into two groups: group I- received custom cast dowel and cores made without the coronal portion anatomy, simulating removal this portion with a bur, and group II- received cores that reproduced the coronal anatomy. Both were treated with an ultrasound device in two three-minute cycles (US). The force necessary for dowel removal was determined using a mechanical test machine. In the second stage of the study, the custom cast dowel and cores were again cemented and no ultrasound vibration was used on them (C). Data were submitted to the two-wayanova (2 × 2) and Tukey test ( P < 0·05), resulting in decreased tensile strength values (Kgf): GIC (49·85 ± 11·10); GIIC (48·22 ± 11·09); GIIUS (32·36 ± 6·21) and GIUS (8·0 ± 7·52). It was concluded that the shape of the core without the anatomic coronal portion facilitated removal of intra-radicular retention only when associated with the use of ultrasound. [ABSTRACT FROM AUTHOR]

In the present study, the biocompatibility of mineral trioxide aggregate (MTA) to the revascularization of the connective tissues was evaluated by using the improved rabbit ear chamber,in vivo. Twenty improved rabbit ear chamber was prepared from 12 male albino-rabbit by using a well through which a material could be introduced into the living vascular tissue. Ten chambers were provided for MTA, and the remaining 10 chambers were used for a calcium hydroxide-containing root canal sealer (Sealapex), as a comparator. A volume of about 1·5 mm3 of the materials were inserted into the chamber and the interaction between the vascular tissue and materials was observed by using a biomicroscope immediately after application, at 1, 3, 5·5, 8, 24, 48, 72 h, and once a week up to 4 weeks. The results revealed that revascularization of connective tissue took place with complete recovery of microcirculation within 4 weeks in both MTA and Sealapex. However, the precipitate-barrier and brown zone around periphery of Sealapex was not observed in MTA treated samples. It can be concluded that MTA is biocompatible and does not produce any adverse site effect on microcirculation of the connective tissue. [ABSTRACT FROM AUTHOR]

The purpose of this in vitro study was to evaluate the effect of gutta-percha solvents on the microhardness and the roughness of human root dentine. Forty-five recently extracted human mandibular anterior teeth were used. The teeth were sectioned longitudinally, embedded in acrylic resin and polished. Ninety specimens were divided into three groups containing 30 teeth each. In group 1, the specimens were treated with chloroform for 15 mm. In group 2, the specimens were treated with halothane for 15 mm. In group 3, distilled water was used and this group was served as control. All groups were then divided into two subgroups of 15 specimens each. The specimens, in groups 1a, 2a and 3a, were submitted to Vicker's microhardness indentations. Groups 1b, 2b and 3b were used for determination of the roughness of root dentine. The data were recorded as Vicker's numbers and Ra, rµm for roughness test. The results were then analysed by one-way ANOVA and post hoc Tukey tests. The results indicated that chloroform and halothane did not affect the microhardness and the roughness of root dentine (P > 0.05). [ABSTRACT FROM AUTHOR]

The removal of radicular posts for endodontic reasons as well as their replacement is a common procedure in dental practice. The use of ultrasound is becoming a standard practice since it reduces the stress to displace the core from the canal minimizing the risks of root fractures, perforations and further wearing of dental structure. Thus, the objective of this study was to evaluate the effect of a reduction in the core diameter when removing radicular posts with ultrasound. Twenty-four teeth were divided in two groups. Group I received posts with the dowel and core of the same diameter (1·7 mm) and group II received posts with the dowel diameter 2 mm larger (3·7 mm) than the core diameter. Zinc phosphate cement was used to cement the posts in all groups. Half of the samples of each group received ultrasonic energy for 8, 2 min for each face. All samples were submitted to traction on an Instron machine (model 4444). Data were analysed statistically with anova and the Tukey test, revealing significant differences ( P < 0·05) between groups. The authors concluded that the mean tension necessary to displace the posts from the roots was reduced by 26% when ultrasound was applied. The reduction of the post-diameter reduced the necessary tension to remove them by 24% compared with larger posts. [ABSTRACT FROM AUTHOR]

The high bond strength between restorative resin and dentine plays an important role in long-term performance of restorations in the oral environment. A variety of treatment techniques have been described to enhance the bond strength of composite resin to dentine. Unfortunately, few studies have reported available bond durability of adhesive resins to dentine. The purpose of this research was to study the shear bond strength of composite resin to dentine pre-treated with phosphoric acid, self-etching agent or Nd:YAP laser irradiation. The durability of bond strength between resin and dentine stored in the artificial saliva thermocycling between 5 and 55 °C was also evaluated. The scanning electron microscope was used to assess the treated-dentine surfaces. The mean value of the shear bond strength in the acid-etching group (18·2 ± 4·9 MPa) was the highest among the three dentine treatments (self-etching system: 12·6 ± 3·0 MPa, Nd:YAP laser: 13·4 ± 3·3 MPa) prior to thermocycling. After thermocycling, shear strength values of all treated dentines decreased with increasing number of the cycles. When subjected to 3000 thermocycles, the mean bond strengths of these pre-treated samples to composite resin became 9·1 ± 1·4, 7·8 ± 1·8, and 8·1 ± 1·7 MPa for acid-etching, self-etching and laser-irradiation, respectively, with a significant reduction of 38–50%. [ABSTRACT FROM AUTHOR]

The aim of this study in vitro investigation was to evaluate the alterations caused by warmed gutta-percha solvents on the calcium, phosphorus and magnesium levels of root dentin. Extracted human anterior teeth, whose crowns and apical root thirds had been removed were used as root dentin specimens. The roots were sectioned longitudinally into two segments, cleaned and dried. Segments were divided into 12 groups (n=12). In 6 groups, the specimens received treatment with the following solvents at room temperature (22 °C): Chloroform, xylene, eucalyptol, orange oil, halothane and saline (control). Within each group, the specimens were further subgrouped into two to be incubated (100% humidity at 37 °C) for 5 and 10 min, respectively, following treatment with the solvents. The remaining six groups were treated with the same solvents which had been previously warmed to body temperature (37 °C) and received the same experimental procedures. The levels of calcium, phosphorus and magnesium in each specimen were analysed using energy dispersive spectrometric microanalysis. Statistical analysis of the readings showed that neither warming of the solvents nor prolonged incubation (treatment) time was capable of altering the histochemical composition of cut root dentin surfaces. [ABSTRACT FROM AUTHOR]

Survival rate and fracture strength of incisors restored with different post and core systems after exposure in the artificial mouth. The survival rate and fracture resistance of 40 decapitated endodontically treated maxillary central incisors using four different post and core systems covered with all-ceramic copings was evaluated after exposure in the artificial mouth. Ten samples of the following post and core systems were investigated: high precious metal post (Permador®*) and core (Olympia®[sup †]) (A), zirconia post (Cerapost®*) with a pre-fabricated bonded ceramic core (Ceracap®*) (B), resin-ceramic post (experimental) with a pre-fabricated bonded ceramic core (Ceracap®) (C) anda zirconia post (Cerapost®) with a custom made ceramic core (Cosmo Ingots®[sup ‡]) (D). The all-ceramic copings (Procera®[sup §]) were cemented using Panavia TC®[sup ¶]. The survival rates after 1 200 000 cycles in the artificial mouth are as follows: 90% (A), 80% (B), 60% (C) and 100% (D). The results of the means and standard deviations (s.d.) of the fracture resistance during static loading are: 1270 ± 312·5 (A), 1494·5 ± 333·5 (B), 1146·7 ± 182·6 (C) and 463·3 ± 46·2 (D). There are statistically significant differences between all groups with the exception of A and B, and A and C (Wilcoxon test). None of the zirconia posts with custom made ceramic cores covered with all-ceramic copings fractured during dynamic loading in the artificial mouth. The mean fracture strength during static loading was less favourable than that of groups A, B and C but above the clinical necessary level. [ABSTRACT FROM AUTHOR]

SUMMARY Porcelain fused to metal provides better aesthetics in fixed partial dentures than veneers with gold‐resin that were used formerly. The aim of our study was to evaluate complications and primary failures of fixed metal ceramic bridge prostheses made by dental students. We studied 61 patients (32 women, 29 men, mean age 49 years, range 28–73 years) treated during years 1990–1993. Data were collected from the patient files. Altogether 82 bridges were made (mean 4·1 units, range 2–6), 221 abutments (mean 2·7, range 2–6) and 136 pontics (mean 1·6, range 1–4). Forty‐seven cast cores were used in 29 bridges (mean 0·4 cores, range 1–3) and semiprecious attachments as an extra attachment in two bridges. Seven teeth were extracted due to complication and/or failure during endodontic treatment and root canal perforation during preparation. In two cases the abutment tooth was fractured by removing the old crown. Four unsuccessful bridges were remade and in seven cases the firing of porcelain was renewed. The study concludes that most common failures of fixed metal ceramic bridges made by dental students occur during root canal preparation of abutment teeth. [ABSTRACT FROM AUTHOR]