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.

Accuracy of fully guided dental implant placement: A prospective clinical in-vivo investigation using intraoral scan data.

AIM: To compare the planned implant position (PIP) with the transferred implant position (TIP) after fully guided implant placements in single-tooth gaps. MATERIALS AND METHODS: Dental implant placements were planned using two different implant systems (Camlog Screw-Line [C-SL] and Straumann Bone Level Tapered [S-BLT]), and two different planning software programs (SMOP and coDiagnostiX). All implants were placed according to fully guided protocols, and intraoral scans were performed intraoperatively. For the comparison of PIP and TIP, scan data were imported to Geomagic Control X (GCX) software and accuracies were evaluated. Deviations were reported in a coordinate system (x- [mesiodistal], y- [vestibulo-oral], and z- [vertical] axis) at entry points and apices. Total deviations, including angular deviations, were calculated with GCX. For statistical analysis, the level of significance was set to P < 0.05. RESULTS: Twenty-six patients received 26 implants. Mean 3D deviation at the implant's entry point was 0.61 mm ± 0.28 for C-SL and 0.63 mm ± 0.24 for S-BLT. For the implant's apex, mean 3D deviation of 0.96 mm ± 0.41 was documented for C-SL and 1.04 mm ± 0.34 for S-BLT. Mean angular deviation was 2.58 degrees ± 1.40 for C-SL and 2.89 degrees ± 1.12 for S-BLT. Statistical analysis revealed no significant differences between implant systems, but showed significant deviations regarding the z-axis, both at entry point and apex (P < 0.05). CONCLUSIONS: Fully guided implant placements in single-tooth gaps provide accurate results. Due to significant vertical deviations, reevaluation of both drilling and insertion depths prior to implant installation should be considered. Maintenance of 1.5- to 2-mm safety distances to critical structures was confirmed.

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.

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.

Mechanical Properties of New Generations of Monolithic, Multi-Layered Zirconia.

New monolithic multi-layered zirconia restorations are gaining popularity due to their excellent aesthetic properties. However, current knowledge of these newest multi-layer ceramics in terms of mechanical properties is scarce. Three monolithic, multi-layered zirconia materials (Katana, Kuraray Noritake, Japan) were selected for comparison: High Translucent Multi-layered zirconia (HTML), Super Translucent Multi-layered zirconia (STML) and Ultra Translucent Multi-layered zirconia (UTML). Fifteen specimens per group were cut from pre-sintered blocs in each of the four layers (L1, L2, L3, L4) and in different thicknesses (0.4 mm, 0.8 mm and 1.2 mm). Critical fracture load (Fcf) was recorded in 3-point-bending. Flexural strength (σ) in MPa, Vickers hardness (HV) in N/mm2, fracture toughness (KIc) in MPa*m1/2, Weibull Modulus (m) and characteristic Weibull strength (σw) in MPa were assessed. Statistical analysis was performed using ANOVA analysis. FS and KIc were significantly higher (p < 0.05) for Katana™ HTML (652.85 ± 143.76−887.64 ± 118.95/4.25 ± 0.43−5.01 ± 0.81) in comparison to Katana™ STML (280.17 ± 83.41−435.95 ± 73.58/3.06 ± 0.27−3.84 ± 0.47) and UTML (258.25 ± 109.98−331.26 ± 56.86/2.35 ± 0.31−2.94 ± 0.33), with no significant differences between layers and layer thicknesses. The range of indications should be carefully considered when selecting the type of monolithic zirconia for fabrication of dental restorations, as materials widely differ in mechanical properties.

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.

Dynamic navigation for dental implant placement in single-tooth gaps: A preclinical pilot investigation.

OBJECTIVES: To compare the planned (PIP) and transferred implant position (TIP) after dental implant placement in single-tooth gaps utilizing dynamic computer-assisted implant surgery (dCAIS). METHODS: Five pairs of artificial jaws (n = 5) with four single tooth gaps in FDI (Fédération Dentaire Internationale) regions 16, 25, 36 and 44 were manufactured via injection molding technique. Cone beam computed tomographies (CBCTs) were made and digital implant planning of twenty implants (n = 20) was performed with a dynamic navigation system (DNS, Navident, ClaroNav, Toronto, Canada). After guided drilling and manual implant placement, post-operative CBCTs were made. Global deviations at entry point (two-dimensional, 2D), apex (three-dimensional, 3D), apex (vertical, V) and angulation (in degrees, °) were calculated by DNS software. For statistical analysis, level of significance was set to p < 0.05. RESULTS: Mean deviation at the implants entry point (2D) was 0.78 ± 0.45 mm (range: 0.10-1.63 mm). For the implants apex (3D) and the implants apex (V) deviations were 1.08 ± 0.50 mm (range: 0.33-2.10 mm) and 0.32 ± 0.22 mm (range: 0.02-0.90 mm), respectively. The median angular deviation (°) was 2.81 ± 2.29° (range: 0.56-9.58°). Statistically significant differences (p < 0.05) were found regarding apex (3D), apex (V), and angulation (°) comparing I.-IV. quadrants. CONCLUSIONS: Using the investigated dCAIS seems to provide satisfactory results regarding TIP in single-tooth gaps in vitro. Due to documented deviations, a safety distance of more than 2 mm should be respected while implant planning in DNS software. CLINICAL SIGNIFICANCE: The investigated DNS seems to be reliant in transferring PIP with acceptable deviations in vitro.

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.

Functional and structural aspects in periodontal furcation treatment: a novel approach.

The outcome in the treatment of furcation defects is often unsatisfactory. The reasons are morphologic and pathologic peculiarities as well as extensive changes in shape caused by resective treatment of periodontal lesions in multi-rooted teeth. Therefore, augmentative strategies are suggested to improve the prognosis. However, the success rate decreases with increasing severity of the disease. In contrast, if the affected roots are not extracted but are extruded after hemi- or trisection, this leads to a coronal displacement of the disease process and a significantly improved situation for hygiene. At the same time, the resection of inflammatory tissue of the periodontal pockets is accompanied by vertical and horizontal bone apposition. The results are predictable and stable in the long term. The burden for the patient is low. ((Quintessence Int 2022;53: 884-891; Originally published (in German) in Quintessenz Zahnmedizin 2020; 71(9): 1024-1032; doi: 10.3290/j.qi.b3418205).

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.

Forced Orthodontic Extrusion: A Practical Therapy Method for Apparently Hopeless Teeth? A Case Report.

The restoration of severely damaged teeth challenges dental practitioners because defects are often located at the subcrestal level. In these cases, surgical crown lengthening or orthodontic extrusion procedures are deemed necessary to maintain the biologic width and respect a sufficient ferrule design after preparation. Considering the negative effects of invasive surgical therapy-such as the reduction of alveolar bone support of the neighboring teeth-forced extrusion might be a valid therapeutic alternative. This clinical case report illustrates forced orthodontic extrusion with a minimally invasive appliance that is applicable in daily clinical routine.