Monolithic hybrid abutment crowns (screw-retained) versus monolithic hybrid abutments with adhesively cemented monolithic crowns.

OBJECTIVES: The objective of this study is to compare monolithic hybrid abutment crowns (screw-retained) versus monolithic hybrid abutments with adhesively cemented monolithic single-tooth crowns. MATERIALS AND METHODS: Twenty subjects in need of an implant-borne restoration were randomly assigned to receive either a cement-retained (CRR) or a screw-retained (SRR) implant-supported monolithic lithium disilicate (LS2 ) reconstruction. Each patient received a titanium implant with in internal conic connection. After osseointegration and second-stage surgery, healing abutments were placed for about 10 days. The type of restoration (CRR vs. SRR) was randomly assigned, and the restorations were manufactured of monolithic LS2 . Both types of restorations, CRR and SRR, were based on a titanium component (Ti-base) that was bonded to the abutment (CRR) or the crown (SRR). The follow-up period for all restoration was 36 months. Clinical outcome was evaluated according to Functional Implant Prosthetic Score (FIPS). Quality of live (OHIP) and patient's satisfaction were assessed using patient-reported outcome measures (PROMs). Primary endpoint was loss of restoration for any reason. Kaplan-Meier curves were constructed and log-rank testing was performed (p < .05). RESULTS: One restoration of group CRR failed after 6 months due to loss of adhesion between Ti-base and individual abutment. No further biological or technical failures occurred. Kaplan-Meier analysis showed no significant difference between both treatment options (p = .317). There was no statistically significant difference between both types of restoration, neither for FIPS, OHIP, treatment time nor patient satisfaction (p > .05). CONCLUSION: Monolithic hybrid abutment crowns (screw-retained) and monolithic hybrid abutment with adhesively cemented monolithic crowns using lithium disilicate showed no statistically significant difference for implant-based reconstructions in this pilot RCT setting.

Health economic evaluation of forced orthodontic extrusion of extensively damaged teeth: up to 6-year results from a clinical study.

OBJECTIVES: Clinical data on retaining extensively damaged teeth using forced orthodontic extrusion followed by restorative rehabilitation are scarce, and economic evaluations are basically absent. A health economic evaluation of this method was performed based on a clinical study. MATERIALS AND METHODS: In a convenience sample of individuals recruited from routine care, extensively damaged teeth were orthodontically extruded prior to restoration. Patients were followed up for up to 6 years. The health outcome was tooth retention time. Direct medical, non-medical, and indirect initial and follow-up costs were estimated using the private payer's perspective in German healthcare. Association of initial direct medical treatment costs and cofounding variables was analyzed using generalized linear models. Success and survival were secondary outcomes. RESULTS: A total of 35 teeth in 30 patients were followed over a mean ± SD of 49 ± 19 months. Five patients (14%) dropped out during that period. Median initial costs were 1941€ (range: 1284-4392€), median costs for follow-up appointments were 215€ (range: 0-5812€), and median total costs were 2284€ (range: 1453 to 7109€). Endodontic re-treatment and placement of a post had a significant impact on total costs. Three teeth had to be extracted and in three patients orthodontic relapse was observed. The survival and success rates were 91% and 83%, respectively. CONCLUSIONS: Within the limitations of this clinical study, total treatment costs for orthodontic extrusion and subsequent restoration of extensively damaged teeth were considerable. Costs were by large generated initially; endodontic and post-endodontic therapies were main drivers. Costs for retreatments due to complications were limited, as only few complications arose. CLINICAL RELEVANCE: The restoration of extensively damaged teeth after forced orthodontic extrusion comes with considerable initial treatment costs, but low follow-up costs. Overall and over the observational period and within German healthcare, costs are below those for tooth replacement using implant-supported crowns. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: DRK S00026697).

Root-analogue implants compared to forced orthodontic extrusion: a retrospective analysis of clinical, radiological and esthetic outcomes after restoration.

OBJECTIVES: To assess clinical, radiological and esthetic outcomes of restorations supported by root-analogue implants (RAIs) or roots of severely damaged teeth after forced orthodontic extrusion (FOE). MATERIALS AND METHODS: Clinical data regarding milled one-piece (titanium/zirconia roots and zirconia abutments) RAIs (REPLICATE™ System) and FOE were recorded and retrospectively evaluated for 40 patients by two investigators. Strict inclusion and exclusion criteria were applied. Functional and esthetic outcomes were assessed for n = 20 pre-molars and n = 20 anterior teeth via comparison of radiographic and digital images applying the novel Functional Implant Prosthodontic Score (FIPS). Krippendorff's alpha coefficient was calculated to assess inter-rater reliability. Mann-Whitney-U-Test was used to compare the assessed parameters. Level of significance was set to p < 0.05. RESULTS: After a mean observation period of 18.4 ± 5.7 months for restorations supported by RAIs and 43.9 ± 16.4 months for restorations after FOE, mean FIPS scores were 9.2/8.8 ± 1.1/1.2 (RAIs) and 7.4/7.7 ± 1.3/1.5 (FOE), respectively. Krippendorff's alpha coefficients did not reveal unacceptable inter-rater reliabilities regarding the investigators and applicability of FIPS. Significant differences were documented when comparing restorations after FOE or supported by RAIs regarding bone loss (p < 0.01), presence of papillae (p < 0.05) and quality and quantity of mucosa (p < 0.02) in favor of FOE. CONCLUSIONS: Within the main limitations of sample size and the retrospective study design, both concepts seem to provide clinically acceptable results. CLINICAL RELEVANCE: Bone- and tissue-preserving characteristics regarding the concept of FOE are promising. It could be applicable for socket preservation and subsequent conventional implant placements in an adapted workflow.

Forced orthodontic extrusion to restore extensively damaged anterior and premolar teeth as abutments for single-crown restorations: Up to 5-year results from a pilot clinical study.

STATEMENT OF PROBLEM: Clinical data on orthodontic extrusion to restore teeth deemed unrestorable because of their defect size are scarce. It remains unclear for which defects forced orthodontic extrusion and tooth retention is preferred to extraction. PURPOSE: The purpose of this pilot clinical study was to investigate the survival, frequency, and type of complications of extensively damaged teeth requiring single-crown restorations after forced orthodontic extrusion. MATERIAL AND METHODS: Participants were recruited from consecutive patients in need of restorative treatment of extensively damaged teeth at a university clinic. The teeth were orthodontically extruded to reestablish the biologic width and to ensure a 2-mm ferrule preparation before restoration. The primary endpoint was restoration success and survival. At recall, survival was defined as the tooth being in situ and success as a symptom-free tooth with an intact, caries-free restoration and with physiological pocket probing depths, no signs of intrusion, ankylosis, root resorption, or periapical radiolucency. Recalls were performed every 6 months; the outcome was assessed by radiographic and clinical evaluation after up to 5 years of clinical service. Quantitative parameters were described with mean values and standard deviations. RESULTS: Thirty-four participants were assessed for eligibility and enrolled (mean ±standard deviation age: 53.4 ±18.9 years). Four participants were premature dropouts. Data were analyzed for 35 teeth in 30 participants. The amount of extrusion varied between 2 and 6 mm (mean ±standard deviation 3.4 ±0.9 mm). The mean duration of extrusion was 18.9 ±12.6 days and the mean duration of retention was 126.94 ±88.1 days. The mean ±standard deviation crown-to-root ratio after treatment was 0.8 ±0.1 (range: 0.5 to 1.0). Three participants exhibited orthodontic relapse before restoration. Teeth were successfully restored after repeated extrusion. After a mean observation period of 3.3 years (range: 1 to 5.2 years), 29 of 31 teeth were still in situ. Two teeth were fractured, and 4 participants were not available for recall. Thus, the survival rate was 94%. No resorption or periapical translucencies were observed radiographically. Clinical examinations revealed physiological probing depths and absence of ankyloses. One tooth presented with marginal bone loss. The most frequent type of complication was orthodontic relapse at recall (n=3). A total of 84% of teeth were considered a success. CONCLUSIONS: Forced orthodontic extrusion allowed for the restoration of anterior and premolar teeth deemed as nonrestorable because of their defect size. Tooth retention of extensively damaged teeth and their use as abutments for single-crown restorations can be recommended.

Impact of endodontic post material on longitudinal changes in interproximal bone level: a randomized controlled pilot trial.

OBJECTIVES: Aim was to evaluate the impact of glass fiber versus titanium endodontic posts on the interproximal bone level around severely damaged endodontically treated teeth. MATERIALS AND METHODS: Thirty-eight participants of a randomized controlled trial on glass fiber (n = 18) and titanium post-endodontic restorations (n = 20) received radiographs at two different times after post placement (T0 = <12 months and T1 = 36-72 months after post placement). A total of 76 radiographs were analyzed with an image-editing software. Medians of changes in mesial and distal interproximal bone level (∆MBL, ∆DBL) were calculated and tested for statistical significance with respect to post material using Mann-Whitney U test (p < 0.05). Impact of post material on bone level changes was assessed in multilevel mixed-effect linear regression models. RESULTS: The mean observation period was 54 months for glass fiber and 50 months for titanium posts. Interproximal bone loss was small in both groups during the study period with no significant differences between groups (glass-fiber group, ∆MBL = - 0.03 mm and ∆DBL = - 0.06 mm; titanium group, ∆MBL = - 0.07 mm and ∆DBL = - 0.17 mm; both p > 0.05). Overall, impact of post material on bone loss was almost negligible with a nonsignificant difference between materials of 0.10 mm during the entire study period. CONCLUSION: The rigidity of endodontic post material has no impact on the level of alveolar bone support of severely damaged endodontically treated teeth. CLINICAL RELEVANCE: Post-endodontic restorations of severely damaged teeth can achieve steady levels of periodontal bone support as a parameter of periodontal health, irrespective of post material.

Patients' self-report on post-retained restoration is more valuable than expected! Explorative analysis of an 11-year follow-up.

Objective: Assessment of long-term clinical data regarding post-endodontic restorations is essential for the evaluation of different post-and-core concepts. The aim of the present study was to assess the diagnostic accuracy of patient self-reporting on post-endodontic restorations after 11 years of clinical service.Materials and methods: Twenty-nine patients (61 ± 15 years old) with endodontic glass-fibre and titanium post-endodontic restorations were examined within the 11-year follow-up of a randomized controlled trial. Restorations were assessed by self-reports during a telephone interview (one item), the completion of a four-item questionnaire and clinical and radiographic examination. A gold standard for restoration in situ or 'failure' was defined by clinical and radiographic examination. Diagnostic accuracy of patients' self-reports was evaluated by calculating the sensitivity, specificity, and positive (PPV) and negative predictive values (NPV).Results: After a mean observation time of 137 months (min/max: 125/154 months), 25 (86.2%) restorations were in situ and 4 (13.8%) failures were detected. Self-report during a telephone interview and the four-item questionnaire correctly identified all in situ restorations (specificity = both 100%, NPV = 92.6%/96.2%). Self-report during a telephone interview identified two out of four failures (sensitivity = 50%, PPV = 100%), and self-report on the four-item questionnaire identified three out of four failures (sensitivity = 75%, PPV = 100%).Conclusions: When the clinical examination is not feasible, patients' self-report shows valuable diagnostic potential in the identification of the post-endodontic failure.

Failure loads of all-ceramic cantilever fixed dental prostheses on post-restored abutment teeth: influence of the post presence and post position.

The influence of a fiber post-restored abutment tooth on the load capability of a three-unit zirconia framework cantilever fixed dental prosthesis (cFDP) was evaluated after simulated clinical function. Human lower sound premolars (n = 64) were distributed, in equal numbers, to four experimental groups: two vital abutment teeth (group I; control); mesial abutment tooth post-restored (group II); distal abutment tooth post-restored (group III); and mesial and distal abutment teeth post-restored (group IV). All specimens received an adhesively luted three-unit cFDP of veneered zirconia. Simulated clinical function was performed by two subsequent sequences of thermal-cycling (2 × 3,000 cycles) and mechanical loading (1.2 × 106 load cycles from 0 to 50 N) (TCML). Four specimens failed during TCML (one in each of groups I and IV and two in group II). The maximum load capability ranged from 365 to 538 N and was not significantly different between groups. Specimens with post-restored abutments failed mainly because of abutment tooth fracture of the distal abutment. The presence or position of post-restored abutment teeth has no significant impact on load capability of all-ceramic three-unit cFDPs. The risk of tooth fracture of the distal abutment teeth of a cFDP was significantly increased when one abutment tooth, irrespective of its position, was post-and-core restored.

Postendodontic Restoration: Endodontic Post-and-Core or No Post At All?

PURPOSE: The objective of this systematic review was to assess the impact of endodontic post insertion on the clinical performance of endodontically treated teeth (ETT). MATERIALS AND METHODS: A specific PICO question was developed and a Medline search was performed in January 2017 using relevant terms in order to identify studies comparing the success/survival of dental restorations using endodontic posts or no posts. Additionally, the electronic databases "Opengrey", "BBO", "LILAC" and "IBECS" were assessed and a hand search of cross references from original articles and reviews was performed. The methodological quality of the included studies was assessed independently by three referees using (1) the critical appraisal skills program (CASP) and (2) Cochrane checklist (version 5.1.0). RESULTS: A total of 14 studies were included, among them 11 randomized controlled trials (RCT), two prospective clinical trials, and one retrospective clinical trial. The overall quality of the studies was good according to the CASP. However, the Cochrane rating showed that in seven studies, the risk of bias was high in > 40% of the items, indicating a relevant level of methodological flaws. Three studies showed a low risk of bias in > 80% of the items. The majority (10 out of 14) of the clinical studies included failed to show a positive effect of post placement. A post effect is possible when no cavity wall is present. CONCLUSION: There is no unequivocal clinical evidence to support or reject the use of posts even for no-wall cavities, either for direct or indirect restorations.

Direct or Indirect Restoration of Endodontically Treated Maxillary Central Incisors with Class III Defects? Composite vs Veneer or Crown Restoration.

PURPOSE: The aim of this ex-vivo study was to evaluate the load capacity of direct or indirect endodontically restored maxillary central incisors with Class III defects, with or without glass-fiber posts. MATERIALS AND METHODS: Seventy-two extracted human maxillary central incisors were endodontically treated and bi-proximal Class III cavities were prepared. Specimens were randomly allocated to six groups (n = 12): direct restoration with composite (C); direct restoration with composite and additional glass-fiber post (CP); ceramic veneer restoration (V), ceramic veneer restoration and additional glass-fiber post (VP), ceramic crown restoration (Cr), ceramic crown restoration and additional glass-fiber post (CrP). Specimens were exposed to thermomechanical loading (TML: 1.2 million cycles, 1 to 50 N; 6000 thermal cycles between 5°C and 55°C for 1 min each), and subsequently linearly loaded until failure (Fmax [N]) at an angle of 135 degrees 3 mm below the incisal edge on the palatal side. Statistical tests were performed using the Kruskall-Wallis and Mann-Whitney U-Test. RESULTS: During dynamic loading by TML, one early failure occurred in group C, CP, and CrP. Subsequent linear loading resulted in mean fracture load values [N] of C = 483 ± 219, CP = 536 ± 281, V = 908 ± 293, VP = 775 ± 333, Cr = 549 ± 258, CrP = 593 ± 259. The Kruskal-Wallis test showed significant differences of load capacity between groups (p < 0.05). Mann-Whitney U-test revealed significantly lower maximum fracture load values of group C compared to group V (p = 0.014), after Bonferroni-Holm correction. Non-restorable root fracture was the most frequent type of failure. CONCLUSION: Endodontically treated maxillary central incisors with Class III defects directly restored with composite are as loadable as indirect crown restorations. Compared to full-coverage restorations, less invasive veneers appear to be more beneficial. Additional placement of glass-fiber posts shows no positive effect.

Why, when, and how general practitioners restore endodontically treated teeth: a representative survey in Germany.

OBJECTIVE: The purpose of this study was to assess current opinions, applied techniques, and materials for the restoration of endodontically treated teeth (ETT) in a nationwide survey in Germany. MATERIAL AND METHODS: Completed questionnaires from 1,648 dentists were returned (response rate 63%). RESULTS: In general, posts were reported to be used more frequently (51%) for indirect restorations than for direct restorations (21%). Dentists restored anterior teeth (65%) more frequently with direct restorations than posterior teeth (48%). Compared to an earlier survey, fewer dentists stated that posttreatment stabilizes the remaining tooth structure. The ferrule effect as a key success factor was held by the vast majority of dentists (88%). A trend towards adhesive techniques both for post placement and core build-up was observed. Composite resins (49%) were reported to be used twice as much as zinc phosphate cement (24%) for the luting of posts; composite resins were the core build-up material of choice (75%). Amalgam was rarely used (0.2%). Irrespective of the final restoration, fiber posts were the most popular post material (46% for telescopic crowns vs. 69% for single crowns). CONCLUSION: Adhesive composite core build-ups with and without fiber posts were the predominant treatment approach to restore ETT in Germany. There was widespread agreement with the ferrule effect as a key restorative success factor for indirect restorations. CLINICAL SIGNIFICANCE: Today, it is general accepted that ferrule preparation is key. Glass-fiber posts appear to be most popular. Still different systems are used depending on type of final restoration, while the reasons to do so remain unclear.

Spectrophotometric assessment of peri-implant mucosa after restoration with zirconia abutments veneered with fluorescent ceramic: a controlled, retrospective clinical study.

OBJECTIVES: The purpose of this study was to investigate the optical appearance of the soft tissue labial to dental implants restored with fluorescent ceramic-veneered zircona abutments. It was hypothesized that the tested abutment design leads to an increased brightness in the marginal peri-implant tissue, which does not differ from that of natural teeth. Moreover, a reduction of the color difference that has been reported from other abutment materials was expected. MATERIALS AND METHODS: A total of 12 patients with single titanium implants in the maxillary anterior region were recruited. All implants (N = 12) were restored with zirconia abutments veneered with fluorescent ceramic and full-ceramic crowns. Color measurements of the peri-implant mucosa at the test sites were made of the facial aspect of the teeth using a Spectroshade-spectrophotometer. The gingiva of a contralateral or adjacent natural tooth served as a control. Color data (CIE-L*a*b* color coordinates) were obtained in five incremental areas of 1 × 2 mm in both test and control sites. ∆E-values were calculated from the ΔL*, Δa* and Δb* values for each patient. RESULTS: Data acquisition from the test site demonstrated lower mean values of L*, a* and b* than the control site. Statistical significance between the test site and control site was reached in the L* values only in the second of the five incremental areas (P < 0.05, Wilcoxon test). However, discrepancies in a*- and b*-values reached a statistically significant difference in the incremental areas 1, 2 and 4, and in b* in area 5 (P < 0.05, Wilcoxon test). Medians of the ∆E-values in all five increments were found to be higher than the clinical perceptual threshold of 3.7. However, considering the original data, five individual patients did not reach the threshold in increment 1 and 2, two in increment 3 and three in increment 4. None of the patients showed lower ∆E-values than the perceptual threshold of 3.7 in increment 5, which had the largest distance from the gingival margin. CONCLUSION: The tested abutment design leads to a peri-implant soft tissue color that, in the critical marginal area, in five of 12 patients did not statistically differ from the tissue of the gingiva of natural teeth. Particularly, the brightness of the peri-implant soft-tissue seemed to be more adapted to the natural situation using a fluorescent abutment design.

Effect of proximal box elevation with resin composite on marginal quality of ceramic inlays in vitro.

OBJECTIVES: The objective of this study was to evaluate the marginal quality and resin-resin transition of milled CAD/CAM glass-ceramic inlays in deep proximal cavities with and without 3-mm proximal box elevation (PBE) using resin composites before and after thermomechanical loading. MATERIALS AND METHODS: MOD cavities with one proximal box beneath the cementoenamel junction were prepared in 48 extracted human third molars. Proximal boxes ending in dentin were elevated for 3 mm with different resin composites (RelyX Unicem, G-Cem, and Maxcem Elite as self-adhesive resin cements and Clearfil Majesty Posterior as restorative resin composite in one or three layers bonded with AdheSE) or left untreated. IPS Empress CAD inlays were luted with Syntac and Variolink II (n = 8). Marginal quality as well as the PBE-ceramic interface were analyzed under an SEM using epoxy resin replicas before and after thermomechanical loading (100,000 × 50 N and 2,500 thermocycles between +5°C and +55°C). RESULTS: Bonding glass-ceramic directly to dentin showed the highest amounts of gap-free margins in dentin (92%, p < 0.05). Bonded resin composite applied in three layers achieved 84% gap-free margins in dentin; PBE with self-adhesive resin cements exhibited significantly more gaps in dentin (p < 0.05). CONCLUSIONS: With a meticulous layering technique and bonded resin composite, PBE may be an alternative to ceramic bonding to dentin. Self-adhesive resin cements seem not suitable for this indication. CLINICAL RELEVANCE: For deep proximal boxes ending in dentin, a PBE may be an alternative to conventional techniques.

Forced Orthodontic Extrusion to Restore the Unrestorable: A Proof of Concept.

The purpose of this clinical study was to assess the feasibility of forced orthodontic extrusion with the Tissue Master Concept to retain subgingivally fractured teeth as abutments for which extraction and replacement would be equal treatment opportunities. Participants were recruited from a group of consecutive patients in need of prosthodontic rehabilitation. In total, 36 deeply destroyed teeth in 31 patients underwent forced orthodontic extrusion with forces exceeding 50 g to reestablish biologic width and ensure a 2-mm dentin-ferrule design prior to single-crown restoration. The primary endpoint was the success of the extrusion in terms of the ability to restore the respective abutment tooth. Information about overall treatment time, frequency, and reasons for failure were collected. Four patients dropped out of the treatment. For the remaining 27 participants, data were fully collected. The amount of extrusion ranged between 2 and 6 mm (3.5 ± 0.9 mm), and the mean duration until retention was 20 ± 12 days. On average, patients returned three (± 3) times for control visits after extrusion. Adhesive failure (n = 6) and orthodontic relapse (n = 2) were the most frequent complication types. Forced orthodontic extrusion may be a useful tool to restore teeth evaluated as nonrestorable.

Evaluating the prospective crown-root ratio after extrusion and crown lengthening procedures in vitro.

For restoration of extensively damaged teeth preprosthetic treatment measures are necessary. Crown lengthening and extrusion affect the prospective crown-root ratio (CRR). The subject of this in vitro study was to compute CRRs for both treatment approaches. 120 human maxillary central extracted incisors were measured. Measurements were calculated for five treatment groups: C (control), E-2 mm (extrusion of 2 mm), E-4 mm (extrusion of 4 mm), CL-2 mm (crown lengthening of 2 mm), and CL-4 mm (crown lengthening of 4 mm). Tooth (TL), root (RL), and crown lengths (CL) were measured from mesial (m) and facial (f) cemento-enamel junction (CEJ), and respective anatomic (CRR) and effective crown-root ratios (eCRR) were calculated. Following CRR values were computed for C: CRR-m = 0.4 ± 0.1, CRR-f = 0.7 ± 0.1. All crown-root ratios were lower (more favourable) for extrusion compared to crown lengthening (p < 0.001). ECRRs were higher than anatomic CRRs. CRR at mesial CEJ was significantly lower than CRR with facial CEJ as reference (p < 0.001). Mesial measurement-based calculations of CRR typically based on radiographic images should be interpreted with caution as they underestimate the eCRR. CRR can be expected as lower, i.e. more favourable, when teeth are extruded than crown lengthened.

Implant or tooth? - A cost-time analysis of managing "unrestorable" teeth✰.

OBJECTIVES: Retaining and restoring severely compromised teeth with subcrestal defect extensions or removing and replacing them using implant-supported crowns (ISC) remains controversial, and economic analyses comparing both strategies remain scarce. We performed a cost-time analysis, comparing the expenditures for retaining "unrestorable" teeth using forced orthodontic extrusion and restoration (FOE) versus extraction and ISC, in a clinical prospective cohort study. METHODS: Forty-two patients (n = 21 per group) were enrolled from clinical routine at a university into this study. Direct medical and indirect costs (opportunity costs) were assessed for all relevant steps (initial care, active care, restorative care, supportive care) using the private payer's perspective in German healthcare based on a micro-costing approach and/or national fee items. Statistical comparison was performed with Mann-Whitney-U test. RESULTS: Patients were followed up for at least one year after initial treatment (n = 40). The drop-out rate was 5% (n = 2). Total direct medical costs were higher for ISC (median: 3439.05€) than FOE (median: 1601.46€) with p<0.001. We observed a higher number of appointments (p = 0.002) for ISC (median: 14.5) in comparison to FOE (median: 12), while cumulatively, FOE patients spent more time in treatment (median: 402.5 min) in comparison to ISC (median: 250 min) with p<0.001, resulting in comparable opportunity costs for both treatment groups (FOE: 304.50€; ISC: 328.98€). CONCLUSIONS: ISC generated higher costs than FOE. More in-depth and long-term exploration of cost-effectiveness is warranted. CLINICAL SIGNIFICANCE: ISCs were associated with higher initial medical costs and required more appointments than the restoration of severely compromised teeth after FOE. Treatment time was higher for patients with FOE, resulting in similar opportunity costs for both treatment approaches. Future research needs to investigate long-term cost-effectiveness.

Fiber post placement with core build-up materials or resin cements-an evaluation of different adhesive approaches.

OBJECTIVE: To compare push-out bond strength of fiber-posts luted with different adhesive approaches to root canal dentin. MATERIALS AND METHODS: Forty maxillary first incisors were decoronated and endodontically treated. Specimens were randomly distributed into five groups (n = 8) and fiber-posts (DentinPost coated, Komet) were inserted using five different luting materials: etch-and-rinse adhesive systems and corresponding core-and-post material in groups 1 (DentinBond/DentinBuild, Komet) and 2 (XP Bond + SCA/Core-X flow, Densply), self-adhesive resin cements in groups 3 (RelyX Unicem, 3M Espe) and 4 (SmartCem 2, Dentsply) and a self-etch adhesive/resin cement in group 5 (ED-Primer II/Panavia F 2.0, Kuraray). The roots were sectioned into eight 1 mm thick serial slices and within 48 h push-out bond strength was investigated. Statistical analyses were performed using non-parametrical Kruskal-Wallis H-test and Mann-Whitney U-test for differences between experimental groups at p < 0.05. The failure modes were analyzed using Chi square test. RESULTS: The bond strength [MPa] (mean/min-max) for groups 3 (12.35/3.60-32.44), 4 (13.52/4.48-30.69) and 2 (11.15/5.23-35.58) were significantly higher (p < 0.001) compared to groups 1 (6.66/2.34-24.89) and 5 (7.41/0.28-34.18). Adhesive failure between dentin and luting agent was the most frequent failure mode. CONCLUSIONS: Bond strength of fiber-posts adhesively luted to root canal dentin was significantly higher when self-adhesive resin cements were used. One (group 2) of the tested core-and-post materials/etch-and-rinse adhesive achieved comparable bond strength values.

Tooth preservation of deeply destroyed teeth by forced orthodontic extrusion: A case series.

Maintaining and restoring teeth exhibiting subgingival or even subcrestal defect extensions represent a common problem in daily practice. Such teeth are often deemed "unrestorable" due to a significant hard tissue loss and defect locations violating the biologic width. In order to achieve a sufficient 2-mm-ferrule design and reestablish the biologic width, both surgical crown lengthening and orthodontic extrusion have been suggested. However, surgical crown lengthening has a negative effect on the attachment level of adjacent teeth as well as esthetic disadvantages particularly in the esthetic zone. Therefore, orthodontic extrusion might be considered as a valid therapeutic alternative since gingival architecture is maintained. While most orthodontic appliances are too complex for daily application, forced orthodontic extrusion by means of the Tissue Master Concept might be a cost- and time-effective approach due to advances in adhesive and computer-assisted dentistry. This clinical case series illustrates the methodology of the rather straightforward Tissue Master Concept in specific clinical situations that may occur in clinical routine.

Long-term Survival of Adhesively Luted Post-endodontic Restorations.

INTRODUCTION: The objective of this prospective clinical study was to investigate survival for endodontically treated teeth restored with adhesively luted prefabricated dentinlike or rigid posts. METHODS: Data were recorded for glass-fiber posts (GFPs) and compared with historical controls evaluating glass-fiber (GFP I) and titanium posts (TPs) for 128 patients. Three groups were defined based on the type of post system used: group 1, GFP I (n = 41); group 2, GFP II (n = 41); and group 3, TP (n = 46). Posts were adhesively luted with self-adhesive resin, adhesive composite core buildups were performed, and all teeth were restored with full-coverage restorations. The primary end point was restoration survival at recall. Outcome was assessed after 6, 12, 24 and up to 178 months clinically and radiographically. Data were analyzed by the Kaplan-Meier log-rank test and Cox regression analysis. RESULTS: After up to 178 months of observation, 26 restorations failed (GFP I: 10, GFP II: 9, and TP: 7) and 49 (GFP I: 18, GFP II: 12, and TP: 19) were in situ. Cumulative survival probabilities were 57.1% for the GFP I, 56.5% for the GFP II, and 71.8% for the TP groups. In bivariate Cox regression, the factors tooth type and grade of abrasion were significantly assfociated with failure. In multivariate Cox regression, none of the investigated factors were significantly associated with failure. The post system had no significant impact on tooth survival (P > .05). CONCLUSIONS: Comparing GFPs and TPs, the post system had no impact on tooth survival up to 15 years. This study indicates that the effect size of post material on survival is low.

Implant or Tooth?-A Prospective Clinical Study on Oral Health-Related Quality of Life for Patients with "Unrestorable" Teeth.

In cases of severely compromised teeth, dental practitioners are confronted with the therapeutic decision of whether to restore a tooth or replace it with an implant. Comparative scientific evidence on patient perception of both treatment approaches is scarce. The subject of this prospective clinical study was to compare oral health-related quality of life (OHRQoL) between two treatment groups: restoration of severely destroyed teeth after orthodontic extrusion (FOE) versus tooth extraction and implant-supported single crown restoration (ISC). A self-selected trial was performed with 21 patients per group. OHRQoL was assessed with the aid of the Oral Health Impact Profile (OHIP-G49) at different time intervals: before treatment (T1), after treatment (T2), after restoration (T3) and at recall (T4). Overall, OHIP scores improved from baseline to follow-up for both concepts with no significant differences between groups. There were no significant differences in subscales between FOE and ISC at T1, T3 and T4. In terms of functional limitations (p = 0.003) and physical disability (p = 0.021), patients in the FOE group temporarily exhibited lower OHRQoL at T2 in comparison to the ISC group. However, at baseline, after final restoration and at recall, the study demonstrates the same level of OHRQoL for both treatment concepts.