Accuracy of Selective Enamel Etching: A Computer-assisted Imaging Analysis.

OBJECTIVE: To assess the accuracy of selective enamel etching (SEE) in a laboratory setup simulating clinical conditions. METHODS AND MATERIALS: A model with permanent human teeth was fabricated. It included a first mandibular molar with a mesio-occlusal-distal inlay preparation, a maxillary central incisor, and a canine with a class IV and class V cavity, respectively. Two dentists (with 1 year and 10 years work experience) repeatedly (n=10 per cavity) performed SEE with a custom gel that had identical rheological properties as a commercially available phosphoric acid etchant. An intraoral scanner was used for image acquisition. To assess the accuracy of SEE, special software was used (OraCheck, Cyfex, Zurich, Switzerland). Two independent investigators analyzed baseline scans and scans taken of the cavities while the gel was in place. The statistical analysis comprised t-tests, Pearson correlation, and analysis of variance (α=0.05). RESULTS: The level of accuracy, whose average values ranged from 61.1% to 87.0%, showed significant differences between teeth, with the highest level observed in the class V cavity, followed by the class II inlay preparation and the class IV cavity (p<0.001). Across the cavities, no significant correlation was observed between the application time and the accuracy of SEE (p=0.07). CONCLUSION: This laboratory study suggests that inadvertent conditioning of dentin adjacent to enamel may be common during SEE. Investigations involving larger samples of dentists are needed to corroborate this finding.

European Society of Endodontology position statement: endodontic management of traumatized permanent teeth.

This position statement represents a consensus of an expert committee convened by the European Society of Endodontology (ESE) on the endodontic management of traumatized permanent teeth. A recent comprehensive review with detailed background information provides the basis for this position statement (Krastl et al. 2021, International Endodontic Journal, https://doi.org/10.1111/iej.13508). The statement is based on current scientific evidence as well as the expertise of the committee. Complementing the recently revised guidelines of the International Association of Dental Traumatology, this position statement aims to provide clinical guidance for the choice of the appropriate endodontic approach for traumatized permanent teeth. Given the dynamic nature of research in this area, this position statement will be updated at appropriate intervals.

Endodontic management of traumatized permanent teeth: a comprehensive review.

The pulp plays a key role in the treatment of traumatic dental injuries (TDIs) and is strongly associated with the outcome, particularly in severe cases. A correct pulp diagnosis is essential as it forms the basis for developing the appropriate management strategy. However, many TDIs are complex, and their treatment requires a profound knowledge of the physiological and pathological responses of the affected tissues. This comprehensive review will look at the dentine-pulp complex and its interaction with the surrounding tissues following TDIs. The literature up to 2020 was reviewed based on several searches on PubMed and the Cochrane Library using relevant terms. In addition to the recently revised guidelines of the International Association of Dental Traumatology, this article aims to provide background information with a focus on endodontic aspects and to gather evidence on which a clinician can make decisions on the choice of the appropriate endodontic approach for traumatized permanent teeth.

Accuracy of the fluorescence-aided identification technique (FIT) for detecting tooth-colored restorations utilizing different fluorescence-inducing devices: an ex vivo comparative study.

OBJECTIVES: The aim of the present study was to compare the accuracy of the conventional illumination method (CONV) and the fluorescence-aided identification technique (FIT) for distinguishing between composite restorations and intact teeth using different fluorescence-inducing devices commonly used for FIT. MATERIALS AND METHODS: Six groups of six dentists equipped with one of six different FIT systems each independently attempted to identify composite restorations and intact teeth on a full-mouth model with 22 composite restorations using CONV and, 1 h later, FIT. The entire procedure was repeated 1 week later. Sensitivity, specificity, and positive (PPV) and negative (NPV) predictive values, including 95% confidence intervals (CI), were calculated for CONV and FIT overall and for each device. The influence of examiner age, method, and device on each parameter was assessed by multivariate analysis of variance. RESULTS: The sensitivity (84%, CI 81-86%), specificity (94%, CI 93-96%), PPV (92%, CI 90-94%), and NPV (90%, CI 88-91%) of FIT was significantly higher than that of CONV (47%, CI 44-50%; 82%, CI 79-84%; 66%, CI 62-69%, and 69%, CI 68-71%, respectively; p<0.001). The differences between CONV and FIT were significant for all parameters and FIT systems except VistaCam, which achieved no significant difference in specificity. Examiners younger than 40 years attained significantly higher sensitivity and negative predictive values than older examiners. CONCLUSIONS: FIT is more reliable for detecting composite restorations than the conventional illumination method. CLINICAL RELEVANCE: FIT can be considered an additional or alternative tool for improving the detection of composite restorations.

Fluorescence-aided Composite Removal in Directly Restored Permanent Posterior Teeth.

AIM: The aim of this study was to quantitatively compare conventional composite removal and composite removal supported by the fluorescence-aided identification technique (FIT) regarding the completeness, selectivity, and duration of the procedure in directly restored permanent posterior teeth. METHODS AND MATERIALS: Two operators removed standardized direct class II composite restorations (n=32 per operator) in human tooth models under simulated clinical conditions. According to a randomized allocation scheme, removal was performed with either the conventional technique (contra-angle handpiece) or supported by FIT. The duration of each removal procedure was recorded. The completeness and selectivity were volumetrically assessed through superimposition of three-dimensional surface scans. Statistical significance was tested by examining the overlap of 95% confidence intervals (CI). Multiple comparison was performed with Tukey tests for each variable. RESULTS: Compared with the conventional technique, composite removal with FIT was faster (329 seconds [95% confidence interval (CI): 268-390 seconds] vs 179 seconds [95% CI: 150-208 seconds]), generated less tooth substance loss (4.53 mm3 [95% CI: 3.77-5.30 mm3] vs 2.77 mm3 [95% CI: 2.11-3.43 mm3]), and left behind less composite residue (1.58 mm3 [95% CI: 1.23-1.94 mm3] vs 0.53 mm3 [95% CI: 0.39-0.67 mm3]). CONCLUSION: Within the limitations of this in vitro study, FIT facilitated the selective and expeditious removal of tooth-colored composites in directly restored posterior teeth.

Changes in periapical status, quality of root fillings and estimated endodontic treatment need in a similar urban German population 20 years later.

OBJECTIVES: The study aimed at assessing, as primary objective, the periapical status and quality of root fillings, and, as secondary objective, the endodontic treatment need of a German urban population in a cross-sectional study 20 years after the first one. MATERIALS AND METHODS: Clinical and radiographic data of 353 patients were evaluated. Descriptive and regression analyses were performed and the endodontic treatment need was calculated. Results were compared with data from the year 1993. RESULTS: A total of 9269 teeth were examined (26.2 teeth per patient; 1993, 24.4), of which 337 teeth were root filled (3.6%; 1993, 2.7%). Prevalence of apical periodontitis in root-filled teeth was 34% (1993, 61%). Quality of root fillings was adequate in 117 cases (35%; 1993, 14%). Minimum endodontic treatment need was estimated with 1.6% (1993, 2.3%), including teeth with clinical symptoms. Considering symptomless teeth with apical periodontitis and poor quality of root filling, the treatment need was 2.9% (1993, 3.7%). Regression analysis identified quality of root filling as a significant factor for periapical health (p = 0.01, odds ratio 3.4×, 95% CI 1.9-6.3×), likewise the type of instrumentation. Teeth treated with rotary files had a significantly better outcome (p = 0.02, odds ratio 2.0×, 95% CI 1.1-3.7×). CONCLUSIONS: Quality of root fillings and the periapical status have improved over the last 20 years in Germany. However, there is still a need for an increase in quality of root canal treatment.

Microguided Endodontics: a method to achieve minimally invasive access cavity preparation and root canal location in mandibular incisors using a novel computer-guided technique.

AIM: To present a novel miniaturized and minimally invasive treatment approach for root canal localization in mandibular incisors with pulp canal calcification and apical periodontitis. SUMMARY: A 51-year-old male patient presented with pain from his mandibular incisors. The patient had a history of severe dental trauma over 30 years ago. Both mandibular central incisors (teeth 31, 41) were tender to percussion and had a yellowish discoloration. They did not respond to thermal and electrical sensitivity tests. Two periapical radiographs from different projections revealed severe pulp canal calcifications and signs of periapical periodontitis. To facilitate the 'Microguided Endodontics' technique, a CBCT and an intra-oral surface scan were aligned using special software. This allowed the virtual planning of optimal access cavities up to the apical third of the root. In this technique, a 3D-printed template guides a customized drill to the orifice of the root canal. After negotiation of the root canals, conventional root canal treatment was performed. This case report demonstrates that minimally invasive and apically extended access cavities are feasible in mandibular incisors with this technique. KEY LEARNING POINTS: The 'Microguided Endodontics' technique is a safe and minimally invasive method for root canal location and prevention of technical failures in anterior teeth with pulp canal calcification.

Comparison of two test designs for evaluating the shear bond strength of resin composite cements.

OBJECTIVE: To compare a shear bond strength test for resin composite cements developed in order to better consider the shrinkage stress (here termed "Swiss shear test") with the shear test design according to ISO 29022. METHOD: Four restorative materials (VITA Enamic (VE), VITA Suprinity (VS), Vitablocs Mark II (VM) and VITA YZ T (YZ)) served as substrate. VE, VS and VM were polished or etched. YZ was polished, sandblasted or etched. Specimens were either bonded according to the Swiss or the ISO shear test. RelyX Unicem 2 Automix, Maxcem Elite and PermaFlo DC were used as cements. Shear bond strength (SBS) was measured. Failure modes (adhesive, cohesive or mixed) were evaluated by means of SEM. RESULTS: Mean SBS values obtained with the Swiss shear test were significantly lower than those obtained with the ISO shear test. VE and VM exhibited similar SBS, values of VS were significantly higher. On etched surfaces VM and VE exhibited primarily cohesive failures, VS primarily adhesive failures. On polished substrates significantly lower bond strength values and exclusively adhesive failures were observed. YZ exhibited solely adhesive failures. Compared to polished YZ, SBS significantly increased after sandblasting and even more after etching. Only for adhesively failed specimens mean SBS values of Swiss and ISO shear test were strongly correlated. SIGNIFICANCE: Both test designs showed the same ranking of test results. When adhesive failure occurred test results were strongly correlated. When cohesive failure was involved, both test designs did not provide reliable results.

A systematic review on the patient perception of periodontal treatment using air polishing devices.

OBJECTIVES: Air polishing devices are used as an alternative to traditional instrumentation of the root surface. The objective of the systematic review was to analyse patient perception, that is pain and discomfort during treatment with air polishing devices in periodontal therapy. METHODS: The electronic databases MEDLINE, EMBASE and the Cochrane library were screened for studies published through 18th November 2013. Patient perception served as primary outcome. RESULTS: Of the 1266 abstracts screened, nine studies reporting data on patient perception using a visual analogue scale or a patient interview were included in the analysis. Different air polishing powders consisting of sodium bicarbonate, glycine or erythritol were used. Reported discomfort of non-surgical periodontal therapy was consistently equal or lower when air polishing powders consisting of glycine or erythritol were applied compared with root surface instrumentation using hand instruments or ultrasonic devices. CONCLUSION: Air polishing with powders consisting of glycine seems to be associated with less discomfort during non-surgical periodontal therapy, that is supra- and subgingival air polishing.

Guided endodontics: accuracy of a novel method for guided access cavity preparation and root canal location.

AIM: To present a novel method utilizing 3D printed templates to gain guided access to root canals and to evaluate its accuracy in vitro. METHODOLOGY: Sixty extracted human teeth were placed into six maxillary jaw models. Preoperative CBCT scans were matched with intra-oral scans using the coDiagnostix(™) software. Access cavities, sleeves and templates for guidance were virtually planned. Templates were produced by a 3D printer. After access cavity preparation by two operators, a postoperative CBCT scan was superimposed on the virtual planning. Accuracy was measured by calculating the deviation of planned and prepared cavities in three dimensions and angle. Ninety-five per cent confidence intervals were calculated for both operators. RESULTS: All root canals were accessible after cavity preparation with 'Guided Endodontics'. Deviations of planned and prepared access cavities were low with means ranging from 0.16 to 0.21 mm for different aspects at the base of the bur and 0.17-0.47 mm at the tip of the bur. Mean of angle deviation was 1.81°. Overlapping 95% confidence intervals revealed no significant difference between operators. CONCLUSION: 'Guided Endodontics' allowed an accurate access cavity preparation up to the apical third of the root utilizing printed templates for guidance. All root canals were accessible after preparation.

A systematic review on the effects of air polishing devices on oral tissues.

OBJECTIVES: Air-polishing devices are used for the instrumentation of the root surface. Their potential of harm to the hard and/or soft tissues needs to be considered during periodontal treatment. The objective of this systematic review was to analyse the effects of air polishing devices on oral tissues. METHODS: The electronic databases MEDLINE, EMBASE and the Cochrane Library were screened for studies published through 18 November 2013. The surface modifications on human cementum, dentine or gingiva after the instrumentation were considered as outcomes. RESULTS: Of the 1266 abstracts screened, 17 studies were included in the analysis. Different air polishing powders consisting of sodium bicarbonate, calcium carbonate, pumice or glycine were used in different ex vivo or in vitro settings. Thirteen publications reported data on the effects of air polishing devices on cementum and dentine. Hard tissue modifications, including defect depths and volume, caused by sodium bicarbonate or calcium carbonate powders were significantly greater compared to powders consisting of glycine. The soft tissue modifications using different modes of instrumentation were assessed in four publications. The data demonstrate less potential of harm to the gingiva after spraying with glycine powder compared to sodium bicarbonate powder or instrumentation with curettes. CONCLUSION: Glycine powder air polishing may be safely applied to human root surfaces and gingivae.

Cost-effectiveness of anterior implants versus fixed dental prostheses.

For the restoration of an anterior missing tooth, implant-supported single crowns (ISCs) or fixed dental prostheses (FDPs) are indicated, but it is not clear which type of restoration is more cost-effective. A self-selected trial was performed with 15 patients with ISCs and 11 with FDPs. Patient preferences were recorded with visual analog scales before treatment, 1 month following restoration, and then annually. Quality-adjusted tooth years (QATYs) were estimated by considering the type of reconstruction for replacing the missing tooth and its effect on the adjacent teeth. A stochastic cost-effectiveness model was developed using Monte Carlo simulation. The expected costs and QATYs were summarized in cost-effectiveness acceptability curves. ISC was the dominant strategy, with a QATY increase of 0.01 over 3 years and 0.04 over 10 years with a higher probability of being cost-effective. While both treatment options provided satisfactory long-term results from the patient's perspective, the lower initial costs, particularly laboratory fees, were responsible for the dominance of ISCs over FDPs.

Antimicrobial effectiveness of intracanal medicaments on Enterococcus faecalis: chlorhexidine versus octenidine.

AIM: To determine the viability of Enterococcus faecalis in infected human root dentine in vitro after exposure to root canal medicaments based on chlorhexidine and octenidine. METHODOLOGY: Human root segments (n = 40) were infected with E. faecalis for 8 weeks. Root dentine samples (rd) collected at week 4 served as individual baseline values. At week 8, the root segments were randomly divided into four test groups (n = 10 each) for the placement of one of the following medicaments in the root canals: calcium hydroxide paste (CH), chlorhexidine gel (CHX-gel) (5.0%), chlorhexidine/gutta-percha points (CHX-GP) (active points(®) ; Roeko, Langenau, Germany) and octenidine gel (OCT-gel) (5.0%) followed by incubation for 4 weeks. The effect on E. faecalis viability was assessed by two fluorescent dyes (syto 9/propidium iodide) to determine the 'proportion of viable bacteria' (PVB%) and number of 'colony-forming units' (CFU). Mean values and 95% confidence intervals (CI) were calculated for PVB% and log CFU, and the difference between groups was established. RESULTS: Viable and dead bacterial cells were detected in all 'rd' samples at weeks 4 and 8. The treatment with CHX-gel, CHX-GP and OCT-gel resulted in significantly lower PVB% values with 15.4%, 3.5% and 0%, respectively. No growth (CFU) was recorded for these samples at week 12. When medicated by CH, the PVB% was increased without a corresponding change in CFUs. CONCLUSIONS: In contrast to calcium hydroxide, both CHX - and octenidine-based intracanal medicaments were effective in decreasing the viability of E. faecalis. OCT showed the most favourable results and may have potential as an endodontic medicament.

Effect of cleaning method, luting agent and preparation procedure on the retention of fibre posts.

AIM: To investigate the effects of various cleaning methods, luting agents and preparation procedures on fibre post retention. METHODOLOGY: In total, 156 human canines were allocated to twelve groups. Teeth were decoronated, instrumented and root filled using warm vertical gutta-percha compaction. Post space preparation was performed in 78 roots using the dedicated preparation drills of the DT Light Post SL system [group post drill (PD)]. Gutta-percha was removed from the other 78 roots using a round bur (RB) (group RB). Within each of these two groups, 26 root canals were rinsed with 1% NaOCl (control), 26 were cleaned using rotating brushes and pumice powder, and 26 were sandblasted with Al(2) O (3) (50 µm) using an intraoral device. Cleanliness of each root canal was investigated using an operating microscope (n = 24) and scanning electron microscope (n = 2). Fibre posts were inserted using self-adhesive resin cement (SmartCem2) or core build-up material (CoreX Flow/XP Bond). Pull-out force was measured using a universal testing machine. Statistical analyses were performed using three-way anova and Tukey's HSD post hoc tests. RESULTS: Root canal cleanliness was not affected by the cleaning method (P = 0.618, chi-squared test). Pull-out force for fibre posts was significantly affected by the cleaning method (P = 0.008), the luting agent (P < 0.0005) and the preparation procedure (P < 0.0005, three-way anova). RB group demonstrated significantly higher pull-out forces [399 (88) N] compared with PD group [287 (105) N]. Posts that were inserted using CoreX Flow/XP Bond exhibited significantly higher pull-out forces [370 (62) N] compared with posts inserted using SmartCem2 [315 (141) N]. CONCLUSION: The different cleaning methods did not lead to significant differences in root canal cleanliness and did not enhance fibre post retention inside the root canal. However, post space preparation using a RB might be beneficial for improving retention, especially when self-adhesive cements are used. The use of the core build-up material CoreX Flow/XP Bond instead of the self-adhesive resin cement, SmartCem 2, resulted in significantly higher pull-out force.

Association of tobacco use and periapical pathosis - a systematic review.

The aim was to review the current evidence regarding an association between tobacco use, that is, cigarette smoking, and periapical pathosis. A systematic MEDLINE search of articles published prior to October 2011 (4th) was conducted using the keywords 'smoking and endodontics OR smoking and periapical index'. The study selection, data preparation and validity assessment were conducted by two reviewers. Nine studies fulfilled the inclusion criteria and represented data from 3008 individuals. The studies differed with respect to (i) study design, (ii) radiographic techniques, (iii) assessment of periapical pathosis, (iv) classification of smoking characteristics and/or (v) potential confounders accounted for in the analyses. Five of six cross-sectional studies revealed a significant positive association (OR 1.35-16.8) between periapical pathosis and current cigarette smoking. One of three longitudinal studies indicated an increased risk (OR 1.7) of root treated teeth for current smokers. The substantial heterogeneity of the included studies limited their interpretation. Further, well-designed studies are required to investigate the association between tobacco use and periapical pathosis.

Tooth discoloration induced by endodontic materials: a laboratory study.

AIM: To investigate the discoloration potential of endodontic materials using a bovine tooth model. METHODOLOGY: Two hundred and 10 dentine-enamel cuboid blocks (10 × 10 × 3.5 mm) were prepared out of the middle thirds of bovine tooth crowns. Standardized cavities were prepared in the walls of the pulp chamber leaving 2 mm of enamel and dentine on the labial wall of the crown. The specimens were randomly assigned to 14 groups (n = 15). Endodontic materials were placed into the cavities as follows: group A: empty, group B: blood, group C: calcium hydroxide, group D: ApexCal, group E: Ultracal XS, group F: Ledermix, group G: triple antibiotic paste (3Mix), group H: grey MTA(GMTA), group I: GMTA + blood, group J: white MTA (WMTA), group K: WMTA + blood, group L: Portland cement (PC), group M: PC + blood and group N: AH Plus. The cavities were sealed with composite and stored in water. Standardized colour measurement (VITA Easyshade compact) was performed at the following intervals: prior to (T0) and after placement of the filling (T1), 1 week (T2), 1 month (T3), 3 months (T4), 6 months (T5) and after 1 year (T6). Colour change (ΔE) values were calculated. A two-way analysis of variance was used to assess significant differences between the endodontic materials. The mean values of all groups were compared using the Tukey multiple comparison test (α = 0.05). RESULTS: Significant differences were detected amongst the experimental groups after 12 months (P < 0.0001). The lowest colour change values were observed in the groups N (AH Plus, 3.2 ± 1.5), A (empty, 3.8 ± 1.4), L (PC, 4.1 ± 1.7), C (calcium hydroxide, 4.7 ± 1.5), E (Ultracal XS, 5.1 ± 1.9) and J (WMTA, 7.9 ± 6.7). The most discoloration was measured in groups G (3Mix, 66.2 ± 9.9) and F (Ledermix, 46.2 ± 11.6). PC showed the best colour stability amongst the Portland cement-based materials; however, when contaminated with blood (group M), a significantly higher ΔE value (13.6 ± 4.2) was detected (P = 0.032). CONCLUSION: Materials used in endodontics may stain teeth. Therefore, the choice of material should not rely solely on biological and functional criteria, but also take aesthetic considerations into account.

Impact of adhesive surface and volume of luting resin on fracture resistance of root filled teeth.

AIM: To investigate the correlation between geometric parameters of severely compromised root filled (RCT) pre-molar teeth with irregular root canals and their fracture resistance. The null hypothesis tested was that the fracture resistance of root filled teeth is not influenced by: (i) the adhesive surface of the post-space preparation (A(PS) ), (ii) the coronal tooth surface (A(A) ), (iii) the amount of resin cement (V(C) ) and (iv) the Young's modulus of the specimens. METHODOLOGY: A total of 48 noncarious human pre-molar teeth with irregular root canals were decoronated, root filled and adhesively restored with post-retained direct composite crowns. After thermomechanical loading (1,200,000×, 5-50° C), static load was applied until failure. The geometric parameters of the tooth were evaluated by microcomputed tomography (µCT) using impressions taken after post-space preparation. Linear regression analyses were performed to correlate the geometric parameters of the specimens with their fracture resistance. RESULTS: The amount of resin cement (V(C) ) comprised up to 88% of the entire post-space (mean 67%) and had no impact on the maximal load (P = 0.88). The latter was significantly influenced by post-space preparation (P = 0.003). CONCLUSIONS: Amongst the geometric parameters tested, the surface area in the root canal had the greatest impact on fracture resistance of root filled pre-molars restored with posts and composite crowns, whilst the fit of the post was less important.

Endodontics or implants? A review of decisive criteria and guidelines for single tooth restorations and full arch reconstructions.

This review describes practical criteria and a systematic process to aid the treatment planning decision of whether to preserve teeth by root canal treatment (RCT) or extract and provide an implant. Recommendations presented are based on best available evidence from the literature and the expert views of specialists in endodontics and restorative dentistry, including dental implantology. A MEDLINE search was conducted using the terms 'root canal therapy', 'dental implants', 'decision making', 'treatment planning', 'outcome' and 'human', and supplemented by hand-searching. When evaluating the outcome of root canal treatment, an observation period of 4-5 years is required for complete healing of periapical lesions. Dental implants, however, present a de novo situation and a functional period of at least 5 years is often required before peri-implant diseases are established and detected. Good long-term success rates and greater flexibility in clinical management indicate that RCT or retreatment should be performed first in most instances unless the tooth is judged to be unrestorable. When deciding if a compromised tooth of questionable prognosis should be maintained or replaced by an implant, both local, site-specific and more general patient-related factors should be considered. Following systematic evaluation and consideration of the best treatment option in a particular case, a treatment recommendation may then be given in favour or against tooth retention. Whilst single risks are possibly accepted for single tooth restorations, teeth with questionable prognosis and multiple pre-treatment requirements are better not included as abutments in fixed dental prostheses to reduce the risk to survival of the entire restoration.

Influence of post fit and post length on fracture resistance.

AIM: To investigate (i) the impact of post fit (form-congruence) and (ii) the influence of post length on the fracture resistance of severely damaged root filled extracted teeth. METHODOLOGY: Ninety-six single-rooted human teeth were root filled and divided into four groups (n = 24 per group). Post spaces were prepared with a depth of 6 mm (group 1, 3) and 3 mm (group 2, 4). Form-congruence with a maximal fit of the post within the root canal space was obtained in groups 1 and 2, whereas there was no form-congruence in groups 3 and 4. In all groups, glass fibre reinforced composite (FRC) posts were adhesively cemented and direct composite crown build-ups were fabricated without a ferrule. After thermo-mechanical loading (1200000x, 5-50 degrees C), static load was applied until failure. Loads-to-failure [in N] were compared amongst the groups. RESULTS: Post fit did not have a significant influence on fracture resistance, irrespective of the post length. Both groups with post insertion depths of 6 mm resulted in significantly higher mean failure loads (group 1, 394 N; group 3, 408 N) than the groups with post space preparation of 3 mm (group 2, 275 N; group 4, 237 N). CONCLUSIONS: Within the limitations of this study, the fracture resistance of teeth restored with FRC posts and direct resin composite crowns without ferrules was not influenced by post fit within the root canal. These results imply that excessive post space preparation aimed at producing an optimal circumferential post fit is not required to improve fracture resistance of roots.

Patient assessment and diagnosis in implant treatment.

As in any dental treatment procedure, a thorough patient assessment is a prerequisite for adequate treatment planning including dental implants. The literature was searched for references to patient assessment in implant treatment up to September 2007 in Medline via PubMed and an additional handsearch was performed. Patient assessment included the following aspects: (1) evaluation of patient's history, his/her complaints, desires and preferences; (2) extra-and intra-oral examination with periodontal and restorative status of the remaining dentition; (3) obligatory prerequisites were a panoramic radiograph and periapical radiographs (at least from the adjacent teeth) for diagnosis and treatment planning. Additional tomographs are required depending on the anatomic situation and the complexity of the planned restoration; (4) study casts are needed especially in more complex situations also requiring a diagnostic set-up, which can be tried-in and transferred into a provisional restoration as well as into a radiographic and surgical template. The current review clearly revealed the necessity for a thorough, structured patient assessment. Following an evaluation, a recommendation is given for implant therapy or, if not indicated, conventional treatment alternatives can be presented.