Cost estimation of single-implant treatment in the periodontally healthy patient after 16-22 years of follow-up.

BACKGROUND: Costs for single-implant treatment are mostly described for the initial treatment. Information on the additional cost related to aftercare is scarce. OBJECTIVE: To make an estimation of complication costs of single implants in periodontally healthy patients after 16-22 years and to compare costs for various prosthetic designs. MATERIALS AND METHODS: Patients with a single implant were recalled for a clinical examination and file investigation. Prosthetic designs included single-tooth (ST) and CeraOne (CO) abutments supporting a porcelain-fused-to-metal (PFM), all-ceramic (CER), or gold-acrylic (ACR) crown. Costs related to failures or technical, biologic, and aesthetic complications were retrieved from patient's records. Total and yearly additional complication costs were calculated as a percentage relative to the initial cost. Chair time needed to solve the complication was recorded and prosthetic designs were compared by Kruskal-Wallis tests. RESULTS: Fifty patients with 59 surviving implants were clinically investigated. Additional complication costs after a mean follow-up of 18.5 years amounted to 23% (range 0-110%) of the initial treatment cost. In total, 39% of implants presented with no costs, whereas 22% and 8% encountered additional costs over 50% and 75%, respectively. In 2%, the complication costs exceeded the initial cost. The mean yearly additional cost was 1.2% (range 0-6%) and mean complication time per implant was 67 min (range 0-345 min). Differences between prosthetic designs (CO, ST-PFM, ST-ACR) were statistically significant for total cost (P = 0.011), yearly cost (P = 0.023), and time (P = 0.023). Pairwise comparison revealed significant lower costs for CO compared with ST-ACR reconstructions. CONCLUSION: Patients should be informed about additional costs related to complications with single implants. The mean additional cost spent on complications was almost one-quarter of the initial treatment price. A majority of implants presented with lower additional costs, whereas the highest complication costs were related to a smaller group with 22% of the implants needing more than half of the initial cost for complication management. Expenses were significantly different for various prosthetic designs.

Normative values for the Oro-facial Esthetic Scale in Sweden.

This study reports the findings and challenges of the assessment of oro-facial aesthetics in the Swedish general population and the development of normative values for the self-reporting Orofacial Esthetic Scale (OES). In a Swedish national sample of 1406 adult subjects (response rate: 47%), OES decile norms were established. The influence of sociodemographics (gender, age, and education), oral health status and general health status on OES scores was analysed. Mean ± standard deviation of OES scores was 50.3 ± 15.6 units (0, worst score; 70, best score); <1% of the subjects had the minimum score of 0, and 11% had the maximum score of 70 OES units. Orofacial Esthetic Scale score differences were (i) substantial (>5 OES units) for subjects with excellent/very good versus good to poor oral or general health status; ii) small (2 units), but statistically significant for gender (P = 0.01) and two age groups (P = 0.02), and (iii) absent for subjects with college versus no college education (P = 0.31) or with and without dentures (P = 0.90). To estimate normative values for a self-reporting health status, instrument is considered an important step in standardisation, and the developed norms provide a frame of reference in the general population to interpret the Orofacial Esthetic Scale scores.

General population norms of the Swedish short forms of oral health impact profile.

We reported the development and psychometric evaluation of a Swedish 14-item and a five-item short form of the Oral Health Impact Profile. The 14-item version was derived from the English-language short form developed by Slade in1997. The five-item version was derived from the German-language short form developed by John et al. in 2006. Validity, reliability and normative values for the two short form summary scores were determined in a random sample of the adult Swedish population (response rate: 46%, N = 1366 subjects). Subjects with sufficient OHRQoL information to calculate a summary score (N = 1309) were on average 50·1 ± 17.4 years old, and 54% were women. Short form summary scores correlated highly with the 49-item OHIP-S (r ≥ 0.97 for OHIP-S14, r ≥ 0.92 for OHIP-S5) and with self-report of oral health (r ≥ 0.41). Reliability, measured with Cronbach's alpha (0.91 for OHIP-S14, 0.77 for OHIP-S5), was sufficient. In the general population, 50% of the subjects had ≥2 OHIP-S14 score points and 10% had ≥11 points, respectively. Among subjects with their own teeth only and/or fixed dental prostheses and with partial removable dental prostheses, 50% of the population had ≥2 OHIP-S14 score points, and 10% had ≥11 points. For subjects with complete dentures, the corresponding figures were 3 and 24 points. OHIP-S5 medians for subjects in the three population groups were 1, 1 and 2 points. Swedish 14-item and 5-item short forms of the OHIP have sufficient psychometric properties and provide a detailed overview about impaired OHRQoL in Sweden. The norms will serve as reference values for future studies.

Long-term follow-up of turned single implants placed in periodontally healthy patients after 16-22 years: radiographic and peri-implant outcome.

OBJECTIVES: Retrospectively evaluate the survival, radiographic and peri-implant outcome of single turned Brånemark™ implants after at least 16 years. MATERIALS AND METHODS: From 134 patients (C-group), 101 could be contacted concerning implant survival and 50 (59 remaining implants) were clinically examined (I-group). Marginal bone level was radiographically measured from the implant-abutment junction at baseline (=within 6 months after abutment connection) and 1-4, 5-8 and 16-22 years post-operatively. Probing depth, gingival and plaque index were measured. Marginal bone-level changes were analyzed using Friedman's and Wilcoxon's signed ranks tests. Spearman's correlations between radiographic and clinical parameters were calculated. RESULTS: In the C-group, 13 out of 166 implants in 11 out of 134 patients failed (CSR=91.5%). In the I-group (28 males-22 females; mean age 23.9 years at baseline; range 14-57), the mean follow-up was 18.4 years (range 16-22). The mean bone level was 1.7±0.88 mm (range -0.8 to 5) after 16-22 years. Changes in the mean marginal bone level were statistically significant between baseline and the second measuring interval (1-4 years). Thereafter, no significant differences could be demonstrated. The mean interproximal probing depth, gingival and plaque indices were 3.9±1.27 mm, 1.2±0.81 and 0.2±0.48, respectively. Probing depth was moderately correlated with gingival inflammation (r=0.6; P<0.001) but not with bone level (P>0.05). 81.4% of the implants had a bone level ≤2nd thread and 91.5% had a probing depth ≤5 mm. 76.3% had both bone level ≤2nd thread and probing depth ≤5 mm. CONCLUSIONS AND CLINICAL IMPLICATIONS: The single turned Brånemark™ implant is a predictable solution with high clinical survival and success rates. In general, a steady-state bone level can be expected over decades, with minimal signs of peri-implant disease. A minority (5%), however, presents with progressive bone loss.

Implants and/or teeth: consensus statements and recommendations.

In August 23-25, 2007, the Scandinavian Society for Prosthetic Dentistry in collaboration with the Danish Society of Oral Implantology arranged a consensus conference on the topic 'Implants and/or teeth'. It was preceded by a workshop in which eight focused questions were raised and answered in eight review articles using a systematic approach. Twenty-eight academicians and clinicians discussed the eight review papers with the purpose to reach consensus on questions relevant for the topic. At the conference the consensus statements were presented as well as lectures based on the review articles. In this article the methods used at the consensus workshop are briefly described followed by the statements with comments.

Early functional loading of Brånemark dental implants: 5-year clinical follow-up study.

BACKGROUND: Short-term clinical studies have indicated the possibility of one-stage surgery and early loading of machined titanium implants. However, long-term data comparing the outcome to the conventional two-stage technique are missing. PURPOSE: A clinical and radiographic study was performed to compare the outcome of oral rehabilitation of the edentulous mandible by fixed suprastructures connected to implants installed according to either (1) a one-stage surgical procedure and early loading (experimental group--EG) or (2) the original two-stage concept (reference group--RG). The EG and RG comprised 16 and 11 subjects, respectively. MATERIALS AND METHODS: The following specific inclusion criterion were adopted: (1) all patients had to consider themselves to be in good general health, (2) the amount of bone had to enable the installation of five to six, at least 10-mm long fixtures (Mk II fixtures; Nobel Biocare AB, Göteborg, Sweden) between the mental foramina, and (3) the patients had to be available for the follow-up and maintenance program. A total of 88 implants were placed in the EG compared to 30 in the RG. In the EG, fixed appliances were connected to the implants within 20 days following implant installation while the fixed appliances in the RG were connected about 4 months following fixture installation. At delivery of the suprastructures, all patients were radiographically examined, an examination that was repeated at the 18- and 60-month follow-ups. RESULTS: The analysis of the radiographs from the EG disclosed that during the observation period, between 18 and 60 months, the mean loss of bone support amounted to 0.2 mm (SD = 0.4). The corresponding value observed in the RG was 0.0 mm (SD = 0.5). During the 60-month observation period, no fixture was lost in any of the two groups examined. The implants under study as well as those in the reference material were at all observation intervals found to be clinically stable. CONCLUSIONS: This clinical study demonstrated that it is, at least based on a 5-year observation period, possible to successfully load via a permanent fixed rigid cross-arch suprastructure titanium dental implants soon after installation. However, such a treatment approach has to be strictly limited to the interforamina area of the edentulous mandible. Furthermore, the bone resorption was found to be within the same range around such implants as around implants installed and loaded according to the original two-stage protocol.

Fixed mandibular restorations on three early-loaded regular platform Brånemark implants.

BACKGROUND: Originally, the Brånemark System was used as a two-stage surgical procedure. Comparable clinical results have made one-stage and early-loading concepts possible alternatives in the edentulous mandible. From the patient's point of view, the financial aspect of implant treatment is important. In an attempt to decrease financial burden, the reduction of surgical interventions and reduction of the number of implants could be considered. PURPOSE: This prospective multicenter study evaluated (1) the 1- and 3-year success rates of implants loaded within 1 month after one-stage surgery with a fixed 10- to 12-unit bridge on three regular platform Brånemark System implants in the mandible, (2) the outcome of the prosthetic treatment, and (3) the opinion of patients regarding the treatment procedure. MATERIALS AND METHODS: Of 20 patients, 19 received five implants in the mandible, of which three were functionally loaded with the one-stage technique (group 1). The loaded implants were inserted in a tripodal position, one implant in the symphysis and two located anterior of the mental foramen in the bicuspid area. Two additional implants were inserted for safety reasons but were not intended to be included in the restoration. These two additional implants served as either an unloaded one-stage control implant (group 2) or an unloaded control implant installed with the submerged technique (group 3). Immediately after surgery, the implants were loaded with a relined denture. The patients received a 10- to 12-unit prosthetic reconstruction an average 31 days (range, 4-53 d) after surgery. Implant stability was clinically checked at 3, 12, and 36 months. Radiographs were taken at corresponding follow-up visits to calculate bone-to-implant level and marginal bone resorption. RESULTS: Six of 60 functionally loaded implants (10%) and 3 of 20 prostheses (15%) failed within the first year. The cumulative implant failure rate in group 1, both after 1 and after 3 years, was 9.5%. No implant failure occurred in the control groups 2 and 3. The average marginal bone level measured at 1 and 3 years was 1.6 mm (SD = 0.8 mm) and 2.1 mm (SD = 0.2 mm), respectively, for group 1; 1.5 mm (SD = 1.3 mm) and 2.4 mm (SD = 0.6 mm), respectively, for group 2; 0.8 mm (SD = 1.4 mm) and 0.7 mm (SD = 0.9 mm), respectively, for group 3. CONCLUSIONS: The results of treatment using three regular platform Brånemark System implants supporting a fixed mandibular arch reconstruction were less favorable than the outcome that can be expected with a standard four- to six-implant with one-stage surgery.

Implant-supported fixed prostheses for the rehabilitation of periodontally compromised dentitions: a 3-year prospective clinical study.

BACKGROUND: The application of a strict hygiene maintenance care protocol following rehabilitation of periodontally compromised dentitions by means of tooth-supported fixed partial dentures has demonstrated excellent long-term treatment outcome. PURPOSE: A clinical and radiographic study was performed to document and evaluate the short- and medium-term result of occlusal rehabilitation by means of implant-supported fixed prostheses (ISFPs) in patients treated for advanced periodontal disease. MATERIALS AND METHODS: Forty-three consecutive patients were included. All patients were referred because of advanced periodontal disease. Before the implant therapy was initiated, periodontal treatment was performed and the outcome evaluated during at least a 6-month period. An individual maintenance care program was designed for each patient. All 125 implants were placed using a two-stage surgical approach. Following installation of the ISFPs, all patients underwent a baseline examination including evaluation of oral hygiene, periodontal or peri-implant conditions, and radiographs. These examinations were repeated annually during the 3-year observation period. RESULTS: No single implant was lost during the 3-year follow-up period. The percentages of plaque-harboring surfaces and bleeding units on probing were found to be low (< 10%), and no soft-tissue complications were recorded. The mean marginal bone resorption during the observation period amounted to 0.21 mm. In a few patients, apposition of marginal bone was observed. Bone loss amounting to 0.5 mm or less was found around 81% of the implants (101/125 implants). The amount of bone loss around the remaining 24 implants (19%) varied between 0.5 and 2.0 mm. CONCLUSIONS: The present clinical trial demonstrates that, at least during a 3-year period, the ISFP is an acceptable and predictable treatment option for rehabilitation in patients who have lost their teeth because of periodontal disease. This observation seems to be valid in edentulous and partially dentate jaws. A prerequisite to reach such a favorable treatment outcome is possibly the combination of the strict maintenance care program and the careful design of the ISFPs.

A new design for a hybrid prosthesis supported by osseointegrated implants: 1. Technical aspects.

Maxillary prosthetic restorations on osseointegrated implants are often problematic because of implant location, orientation, and need for lip support. A new design for a hybrid maxillary prosthesis that will provide good esthetics and phonetics, as well as ensure optimum conditions for oral hygiene and patient comfort, is proposed. The design includes separate support, lateral stabilization, and retention. Support is derived from elevated areas at the midline and on the extensions of a bar screwed to dental implants ad modum Brånemark. Lateral stabilization is obtained by a removable framework closely fitting the bar. Four precision attachments provide adjustable retention without influencing support. Technical aspects of the procedure are described.

A new design for a hybrid prosthesis supported by osseointegrated implants: 2. Preliminary clinical aspects.

A fixed partial denture is preferred as a prosthetic restoration supported by tissue-integrated oral implants. However, there are occasions, especially in restoring an edentulous maxilla, when a fixed partial denture does not satisfy a patient's requirements for esthetics, good phonetics, proper oral hygiene, and oral comfort. A removable hybrid prosthesis attached to a bar that is conventionally fixed to tissue-integrated implants ad modum Brånemark was therefore designed to satisfy such needs and to meet requirements for splinting of the implants. Following the placement of prostheses, patients were asked to give their opinion on the comfort, phonetics, and esthetics of the prosthesis by marking a visual analog scale. The results indicate a successful initial outcome of the treatment.

Surface properties and castability of elastomeric impression materials after plasma cleaning.

The wettability of impression materials is an important requirement for accurate reproduction of intraoral structures. The aims of this study were to evaluate the effect of plasma cleaning on critical surface tension and die stone castability of five silicone impression materials. Critical surface tension was calculated using a contact angle analysis according to Zisman (1964), before and after plasma cleaning. Die stone casts were produced from impressions of a master die and the area extension of the reproduction was measured planimetrically. The results showed a general increase in the critical surface tension and in the polar force component of the composite free energy for materials treated with plasma cleaning. An improvement in castability of all materials was also noted.

Overdentures--when and how.

Implant borne overdentures are a reliable and simple solution to denture retention and stability problems. Such a treatment option requires careful planning and the basis for this is made from the results of clinical trials. An overdenture symposium on this subject was held at Naantali, Finland on 26th August, 1994. The following paper is a summary of the proceedings.

Biomechanical aspects on overdenture treatment.

OBJECTIVES: Implant retained overdentures utilize a wide range of attachments to provide the retentive forces for implant retained overdentures. Such attachments attempt to minimize the functional stresses at the implant-overdenture interfaces. STUDY SELECTION: Clinical experiments with strain gauges can monitor the types and magnitudes of deformation that appear in the underlying surfaces. Clinical results have shown that fixed and removable prostheses perform differently in type, magnitude and direction of the applied load from laboratory tests. There is good correlation between short term clinical experiments and long term clinical follow-ups of prosthesis provision. Removable prosthetic superstructures perform at a lower level of overall functional rigidity with increased risk of deformation. Factors that influence the loading patterns and surface straining are the incorporation of an internal metal frame, the rheological properties of the foodstuff, the occlusal position of the teeth and the degree of fit of the prosthetic suprastructure and the implants. CONCLUSIONS: The prognosis of implant retained overdentures is maximized when the number of fixtures used is high, a rigid bar design is used and functional flexibility is incorporated in the prosthesis design.

Clinical performance of three anterior restorative materials over 10 years.

The long-term performance of two chemically activated composite resins was compared to that of one silicate cement. Bulk and cavosurface marginal discoloration was evaluated with both an indirect photographic method and the direct US Public Health Service evaluation system. The results confirmed that composite resins had superior performance but higher secondary caries incidence than did silicate cements. The macrofilled composite resins showed better clinical performance than the microfilled restorations, as well as similar incidences of bulk and marginal discoloration. The agreement between the scores obtained with the direct evaluation criteria and those resulting from the indirect evaluation method was relatively poor. The indirect scores were usually the same or poorer than the direct clinical scores. The results indicated that the clinical evaluation may be the least sensitive of the two methods. The discrepancy in the scorings may, on the other hand, signify that the indirect photographic method records reflectance spectra that are not normally obtained in vivo.

Studies of electrochemical action in the oral cavity.

A method for in vivo measurements of potentials and polarizations of metallic dental restorations was presented. The precision of this method allowed for calculation to be made of the electrochemical action in the oral cavity in terms of currents created at contact between metallic restorative materials. With this method, an epidemiological investigation was performed on persons, who had received dental treatments including extensive metallic restorations. Those persons suffering from oral symptoms allegedly caused by oral galvanism were not found to have higher electrochemical action in the oral cavity than persons, selected as a control, without symptoms ascribed to oral galvanism. Persons ailing from this type of symptoms showed, however, lower threshold levels for electric stimulation, examined with an electrogustometric method, than persons without symptoms. Finally, determination of the saliva concentrations of various metallic components with atomic absorption spectrophotometry did not reveal any differences between persons with or without metallic restorations. Neither were any correlations found between saliva ion concentrations and the magnitude of currents created at metallic contact between dental restorations.

On electric current creation in patients treated with osseointegrated dental bridges.

Electric currents are created when metals or metal alloys are immersed and make contact with each other in an electrolyte. As such metallic contacts are created in the oral cavity also at treatments with osseointegrated fixed bridges ad modum Brånemark, the generated currents were studied in vivo. In four subjects, all wearing osseointegrated mandibular dental bridges and complete maxillary acrylic dentures, the bridges were removed leaving the osseointegrated titanium abutments exposed in the oral cavity. Potentials and polarizations were determined independently for all the titanium abutments and gold alloy bridges and from the obtained data the maximum electric currents generated at contact between the materials were calculated. The results of this study showed that, generally speaking, in the oral cavity dental gold alloy was electrochemically more noble than titanium implants. The mean potential difference between the two metallic systems was found to be 73 mV and the mean generated maximum electric currents was in the magnitude of 26 microA at oral contacts between titanium and dental gold alloy.

Reproduction of details using dental stones and investment material in impressions of elastomers and waxes.

In the fabrication of crowns and inlays it is very important that all the details of the impression are exactly reproduced by the cast. These requirements prevail between elastomeric impression materials and dental stones as well as between waxes and investment materials. Inadequate filling of the details of the impression will result in rounded inner corners of the casting, which then may not properly seat on the prepared tooth. Two brands of elastomeric impression material, dental stone, wax, investment material and wetting agent were chosen to study the reproduction of details. A master model of stainless steel, shaped like a truncated cone with a convex top and 60 degrees threads, was used. The shape of this model made it possible to make microscopic measurements of the reproduced detail of the threads. No significant difference, by different prepouring treatment of the impressions was found in reproducing details with elastomeric impression materials and dental stones. All combinations of elastomeric impression materials and dental stones reproduced, however, significantly more details than combinations of waxes and investment materials. The relevance of transferring conclusions from the laboratory investigation to clinical conditions are discussed as well as the clinical value of reproducing details.

Intraoral currents and taste thresholds.

A group of patients, with oral symptoms such as oral smart, battery taste and mental taste, were examined to study the relationship, if any, between intraoral currents, created at metallic contacts between restorative materials, and taste perception thresholds. The patients were examined with an electrogustometric method for determination of taste threshold levels. Further the intraoral currents were calculated from data obtained at potential and polarization measurements. Comparisons were then between groups of subjects with and without oral symptoms. The results of this study indicate that patients with certain oral symptoms have lower threshold levels for electric taste stimulation than persons in a control group selected at random. No differences were, however, observed between the magnitudes of intraoral currents in the two groups.

Masticatory efficiency in individuals with natural dentition.

51 healthy dentate subjects aged between 20 and 60 years were evaluated with regard to their masticatory efficiency using a sieving test. A subjective evaluation of difficulty in chewing different kinds of food was also obtained by means of a questionnaire. The occlusal and restorative status were assessed using specific indices. The masticatory efficiency was shown to be lower with increasing age 20-39 years, mean = 39.8 and 40-60 years, mean = 27.1, respectively (p < 0.05). Males had a statistically significantly higher masticatory efficiency index than females. Multiple regression analysis showed that age, sex, the number of occluding teeth and the orthodontic treatment need index can predict half the variance in masticatory efficiency. It is concluded that it is more appropriate to describe masticatory efficiency with an average value for different age groups.

Effect of selenium on mercury vapour released from dental amalgams: an in vitro study.

Wet corroded and air oxidized surfaces from different types of dental amalgams were used in this in vitro study. The mercury vapour released before and after standardized brushing with a conventional (ACTA) and an experimental selenium-containing toothpaste was examined. The results showed differences between the wet corroded and the air oxidized surfaces. High copper, non- gamma 2- amalgams, released more mercury vapour than the conventional one throughout the experiment. When the amalgam surfaces were brushed with the conventional toothpaste, an increase of the released vapour was noted. The use of the selenium containing toothpaste resulted in all cases, in significantly lower amounts of mercury vapour.