Dental implant treatment in patients with cancer on high-dose antiresorptive medication: A prospective feasibility study with 2 years follow-up.

OBJECTIVES: Dental implant treatment is considered contraindicated in patients with cancer on high-dose antiresorptive medication (HDAR). The aim of this prospective, feasibility study was to evaluate implant treatment in patients with cancer on HDAR, in terms of implant survival, implant success, and oral health-related quality of life (OHLQoL) after 2 years of loading. MATERIALS AND METHODS: Implants were inserted in three groups of HDAR patients: (1) Previous tooth extraction, no medication-related osteonecrosis of the jaw (MRONJ), (2) Previous MRONJ, now healed, (3) Existing MRONJ, planned surgical resection. Implants were placed without adjunctive bone or soft tissue argumentation. Abutment operation was performed after ≥12 weeks. Prosthetic treatment was initiated ≥14 weeks. Survival and success rate were determined, and OHLQoL was analyzed with OHIP-49 and QLQ-H&N35 questionnaires. Patients were seen for 6 months, 1- and 2 years follow-up. RESULTS: Twenty-two patients, 39 implants, completed the implant-based prosthetic treatment. Implant-supported crowns and overdentures were fabricated. Thirteen patients (59%) with 23 implants (59%) completed 2 years follow-up. Overall implant survival and success rate after 2 years of loading were 100% and 97.4%, respectively. OHLQoL for the patients increased in all groups after the treatment, a substantial increase was seen in group 3. Two patients developed MRONJ, but not related to the implant treatment. CONCLUSION: Dental implant treatment, with high survival and success rate and increased post-treatment OHLQoL, is feasible in HDAR patients after 2 years of loading. Caution with general recommendations should be exercised.

Positional changes of maxillary central incisors following orthodontic treatment using single-crown implants as fixed reference markers.

OBJECTIVES: This follow-up study (1) compares tooth displacement of central incisors in patients with and without pre-implant orthodontic treatment and (2) investigates whether sex, age, or orthodontic retention have an effect on tooth displacement after the insertion of single-crown implants. MATERIALS AND METHODS: Fifty-seven patients - thirty-seven with (test group) and twenty without pre-implant orthodontic treatment (control group) - were rehabilitated with 89 single-crown implants in the upper maxilla. Clinical and radiographic data, clinical photographs, and dental casts were collected during baseline examinations after prosthetic rehabilitation and at the final follow-up examination at least 5 years later. A total of 114 dental casts were digitalized and aligned using a software program to measure changes in the positions of the central incisors. RESULTS: After a follow-up period of at least five years, 87% of the central incisors measured in the test group were displaced >0.25 mm vertically compared with 70% in the control group. Seventy-eight percent of the test group teeth had moved >0.25 mm horizontally compared with 55% in the control group. These differences were not significant, and there were no significant correlations with patient age or sex. CONCLUSION: The majority of patients had minor vertical (60%) or horizontal (67%) tooth displacement of the central incisors (0.25-0.75 mm) after a minimum follow-up period of 5 years. This study found no significant differences in tooth displacement comparing patients with and without pre-implant orthodontic treatment. No significant effect of sex, age, orthodontic retention, or implant location was observed on tooth displacement.

Oral health-related quality of life and complications after treatment with partial removable dental prosthesis.

The aims of this study were to measure and describe the oral health-related quality of life (OHRQoL) and to identify the complications caused by partial removable dental prosthesis (RDPs) in patients 1-5 years after treatment. Complications were identified in 65 patients who were treated with 83 RDPs (48 upper, 35 lower). OHRQoL was measured using the OHIP-49 before treatment and at the baseline (1-2 months after treatment) and follow-up (1-5 years after treatment) examinations. The types and numbers of oral problems that were experienced were described based on OHIP items with a score of 3 and 4. A significant improvement (P < 0·05) in the total OHIP-49 was registered from pre-treatment (mean 42, SD ± 37) to baseline (mean 29, SD ± 27) and from pre-treatment to 1-5 years after treatment (mean 32, SD ± 30). There was no significant difference between the baseline and 1- to 5-year follow-up examinations. Problems with eating and appearance registered at pre-treatment were improved at baseline and after 1-5 years. Problems with dentures that had been registered pre-treatment were improved at baseline but reoccurred after 1-5 years. The two most frequent complications were ill-fitting RDPs and inflammation of the oral mucosa, followed less frequently by fractures of the clasps. Treatment with RDPs improved OHRQoL, but denture-related problems partly remained, and new problems related to RDPs occurred 1-5 years after treatment. The two most frequent complications were ill-fitting RDPs and inflammation of the oral mucosa.

From brain to bridge: masticatory function and dental implants.

Masticatory function is an important aspect of oral health, and oral rehabilitation should aim to maintain or restore adequate function. The present qualitative review is the joint effort of a group of clinicians and researchers with experiences ranging from basic and clinical oral neuroscience to management of patients with dental implants. The aim is to provide a short summary for the clinician of the many aspects related to masticatory function (including quality of life) and rehabilitation with dental implants. While there are many reviews on the tissue responses to dental implants and technical aspects, the functional aspects have received relatively little focus.

Effect of treatment with fixed and removable dental prostheses. An oral health-related quality of life study.

The aim of the study was to evaluate patient-reported effects of treatment with fixed dental prostheses (FDP) and removable dental prostheses (RDP) and relate the change in Oral Health Related Quality of Life (OHRQoL) to the type of treatment and objective dental variables of aesthetics and mastication. Additionally, the purpose of the study was to identify aspects of impairment and improvement that the treatments caused. Fixed dental prostheses treatment was performed in 200 patients and RDP treatment in 107 patients. Gender, age, region of replacement, and number of teeth present and replaced were obtained. The participants completed the Oral Health Impact Profile 49 (OHIP-49) before and after treatment. A control group with no need for dental treatment also completed the OHIP-49. All participants had a significant improvement in OHRQoL. The improvement was higher for the RDP group than the FDP group. Removable dental prostheses that replaced only masticatory teeth did not improve the OHRQoL significantly. The improvement in OHRQoL for both the FDP and RDP groups was not at the level of the control group. Higher age was associated with lower improvement in OHRQoL. Higher age, being a woman and having teeth replaced in the aesthetic zone were associated with deterioration in OHRQoL. Both RDP treatment and FDP treatment were associated with a reduction in the problems most frequently reported before treatment. Treatment with RDP was associated with new problems caused by the RDP. Fixed dental prostheses and RDP treatments improved OHRQoL and reduced the number of problems. The RDP participants improved more than the FDP participants.

Comparison of an individual systematic interview method and the oral health impact profile. Responsiveness and ability of describing treatment effect of oral rehabilitation.

The Schedule for the Evaluation of Individual Quality of Life - Direct Weighting (SEIQoL-DW) has shown potential for generating information and measuring Oral Health-Related Quality of Life (OHRQoL) in oral rehabilitation. The Oral Health Impact Profile-49 (OHIP-49) has been widely used in population studies. The purpose of this study was to compare the responsiveness and ability of the SEIQoL-DW and the OHIP-49 to qualitatively describe the change following oral rehabilitation. Twenty-two participants treated with fixed or removable prosthesis were interviewed before and after treatment using the SEIQoL-DW and the OHIP-49 questionnaire. The participants rated the subjective perception of change and answered two global oral rating questions. A clinical examination was performed to identify dental status variables. No significant difference was found between pre- and post-treatment SEIQoL-DW scores. A significant difference between pre- and post-treatment OHIP-49 scores was found. The SEIQoL-DW and OHIP-49 change scores was significantly correlated. The dental status variables such as number of teeth, number of teeth replaced, number of occluding units, type of treatment, extractions and removable dental prosthesis (RDP) before treatment did not influence the change scores. The effect size was low for the SEIQoL-DW (0.15) and moderate for the OHIP-49 (0.60). Improvement in subjective perception of change was related to both improvement and deterioration in change scores. More aspects were mentioned in the SEIQoL-DW compared to the OHIP-49. Based on the change in overall score and effect size, the SEIQoL-DW showed a weaker responsiveness than the OHIP-49. The SEIQoL-DW, however, described the change more detailed than the OHIP-49.

Patient-generated aspects in oral rehabilitation decision making I. Comparison of traditional history taking and an individual systematic interview method.

Decision making in oral rehabilitation is often based on diagnoses related to impairment of different oral functions. In making the decision when to treat, the dentist must work in cooperation with the patient. By incorporating patient-generated aspects into the decision making process, the dentist finds it easier to decide if and why treatment should be undertaken and what treatment modality to use. The purpose of this study was to describe the potential of an interview method, the 'Schedule for the Evaluation of Individual Quality of Life-Direct Weighting' (SEIQoL-DW), and compare it with a traditional history taking, in generating information to be used in decision making in oral rehabilitation. Fifty-seven participants in need of oral rehabilitation were enrolled in the study. The participants underwent a traditional history taking and were interviewed using the SEIQoL-DW method. The SEIQoL-DW generated a high number of cues for all participants. Significantly more cues and additional information were generated by the SEIQoL-DW than by the traditional history taking. The additional information concerned consultation and dentist issues, psychological aspects and treatment preferences. A high percentage of the participants were positive towards the use of the SEIQoL-DW method in their treatment planning. The SEIQoL-DW was considered to be a viable tool for decision making in oral rehabilitation.

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.

Spontaneous progression of ligature induced peri-implantitis at implants with different surface roughness: an experimental study in dogs.

BACKGROUND: Peri-implantitis is associated with the presence of submarginal plaque, soft-tissue inflammation and advanced breakdown of the supporting bone. The progression of peri-implantitis following varying periods of continuing plaque accumulation has been studied in animal models. OBJECTIVE: The aim of the current experiment was to study the progression of peri-implantitis around implants with different surface roughness. MATERIAL AND METHODS: In five beagle dogs, three implants with either a sandblasted acid-etched surface (SLA) or a polished surface (P) were installed bilaterally in the edentulous premolar regions. After 3 months on a plaque control regimen, experimental peri-implantitis was induced by ligature placement and plaque accumulation was allowed to progress until about 40% of the height of the supporting bone had been lost. After this 4-month period, ligatures were removed and plaque accumulation was continued for an additional 5 months. Radiographs of all implant sites were obtained before and after 'active' experimental peri-implantitis as well as at the end of the experiment. Biopsies were harvested and the tissue samples were prepared for light microscopy. The sections were used for histometric and morphometric examinations. RESULTS: The radiographic examinations indicated that similar amounts of bone loss occurred at SLA and P sites during the active breakdown period, while the progression of bone loss was larger at SLA than at polished sites following ligature removal. The histological examination revealed that both bone loss and the size of the inflammatory lesion in the connective tissue were larger in SLA than in polished implant sites. The area of plaque was also larger at implants with an SLA surface than at implants with a polished surface. CONCLUSION: It is suggested that the progression of peri-implantitis, if left untreated, is more pronounced at implants with a moderately rough surface than at implants with a polished surface.

Resistance to cyclic loading of teeth restored with posts.

This in vitro study evaluated the effect of presence of post, presence of core, and of shape, type, and surface treatment of posts on resistance to cyclic loading of crowned human teeth. For all teeth, crowns designed without ferrule were cast in sterling silver and luted with resin cement (Panavia F). Each tooth underwent cyclic loading of 600 N at two loads per second until failure. Teeth that had only been crowned showed significantly higher resistance to cyclic loading than teeth with cores or with post and cores. No significant differences were found between teeth restored with cores only or with post and cores, irrespective of surface-treatment of the posts. Teeth restored with parallel-sided cast post (ParaPost XP) and cores showed significantly higher resistance to cyclic loading than teeth with either tapered cast posts or untreated prefabricated posts of titanium alloy (ParaPost XH) or glass fiber composite (ParaPost Fiber White). No significant difference was found between teeth restored with parallel-sided cast post and cores and teeth restored with untreated prefabricated posts of zirconia (Cerapost). Surface treatment of posts significantly increased the resistance to cyclic loading compared with untreated posts. When posts are used, surface treatment is recommended.

Bone reactions at implants subjected to experimental peri-implantitis and static load. A study in the dog.

AIM: The aim of the present experiment was to study peri-implant tissue reactions to lateral static load at implants subjected to experimental mucositis or peri-implantitis. MATERIAL AND METHODS: 5 beagle dogs were used. The mandibular premolars were extracted. After 12 weeks, 3 implants were installed in each quadrant of the mandible. In one side, the implants were designed with a SLA surface and in the contralateral side with a turned surface. A plaque control program was initiated. 12 weeks later, the central and posterior implants were connected with an appliance containing an expansion screw. Cotton ligatures were placed around the neck of the anterior and posterior implants in both sides, and the plaque control measures were terminated. Sixteen weeks later the ligatures were removed. After 8 weeks without ligatures, the expansion screws in both sides were activated. Once every 2 week during a 12-week interval, the screws were reactivated. Thus, the model included 3 different experimental sites of each surface group: group M+L (mucositis+load); group P (peri-implantitis); group P+L (peri-implantitis+load). Fluorochrome labels were injected and standardized radiographs obtained. The animals were sacrificed and block biopsies of all implant sites dissected and prepared for histological analysis. RESULTS: It was demonstrated that the lateral static load failed to induce peri-implant bone loss at implants with mucositis and failed to enhance the bone loss at implants with experimental peri-implantitis. The proportion of bone labels and the bone density in the interface zone were significantly higher in group P+L than in group P. CONCLUSION: It is suggested that a lateral static load with controlled forces may not be detrimental to implants exhibiting mucositis or peri-implantitis.

Bone reactions adjacent to titanium implants subjected to static load of different duration. A study in the dog (III).

The aim of the present experiment was to study the effect of a long-standing lateral static load on the peri-implant bone. Three beagle dogs were used. The mandibular premolars were extracted and 12 weeks later 3 titanium implants (ITI(R) Dental Implant System) were installed in each quadrant. Crowns were fitted to all implants 12 weeks after the installation procedure. The anterior and central crowns were fused and connected to the posterior crown by an expansion screw. In the right side of the mandible, the expansion screws were activated every 2 weeks during a 46-week period. During the last 10 weeks of this period, an expansion force similar to that of the right side was applied in the left. The animals were sacrificed and block biopsies of each implant site harvested and prepared for histological analysis. Sites subjected to 10 weeks or 46 weeks of lateral load had a similar (i) distribution of bone markers (ii) proportion of bone density and (iii) degree of bone-to-implant contact. The proportion of fluorochromes was higher at sites subjected to 10 weeks of loading than at sites subjected to 46 weeks of loading.

A prospective 5-year study of fixed partial prostheses supported by implants with machined and TiO2-blasted surface.

PURPOSE: The aim of the present study was to evaluate whether there was a difference between machined and TiO(2)-blasted implants regarding survival rate and marginal bone loss during a 5-year observation period. MATERIALS AND METHODS: A total of 133 implants (Astra Tech Dental Implants; Astra Tech AB, Mölndal, Sweden) were placed in 50 patients at 6 centers in 4 Scandinavian countries. Forty-eight implants were installed in the maxilla and 85 implants in the mandible. A randomization and a stratification were done, so that each fixed partial prosthesis was supported by at least 1 machined and 1 TiO(2)-blasted implant. The implant-supported fixed partial prostheses (ISFPP) were fabricated within 2 months after postoperative healing. A total of 52 ISFPP (17 maxillary, 35 mandibular) were inserted. The patients were clinically examined once a year for 5 years. At the annual follow-up, biological as well as technical complications were recorded. RESULTS: Of the 133 implants placed, 3 were reported as failed after 5 years of follow-up, resulting in an overall cumulative survival rate of 97.6%. The cumulative implant survival rates were 100% for the TiO(2)-blasted implants and 95.1% for the machined implants. No significant difference in survival was, however, found between the machined and TiO(2)-blasted implants after 5 years. The mean marginal bone loss in the maxilla was 0.21 +/- 0.83 mm (SD) for the machined implants and 0.51 +/- 1.11 mm (SD) for the TiO(2)-blasted implants during the 5-year observation period. In the mandible, the mean marginal loss was 0.22 +/- 1.13 mm for the machined implants and 0.52 +/- 1.07 mm for the TiO(2)-blasted implants from baseline to the 5-year examination. No significant difference in marginal bone loss between the 2 surface groups was found during the 5-year observation period. CONCLUSIONS: The present study shows good 5-year results with small ISFPP in the mandible, as well as in the maxilla. No significant differences were found in failure rate and marginal bone loss around implants with a machined rather than a TiO(2)-blasted surface. J Prosthodont 2001;10:2-7.

Bone reactions adjacent to titanium implants with different surface characteristics subjected to static load. A study in the dog (II).

The purpose of the present study was to compare bone reactions adjacent to titanium implants with either a titanium plasma-sprayed (TPS) or a machined surface subjected to lateral static loading induced by an expansion force. In 3 labrador dogs, the 2nd, 3rd and 4th mandibular premolars were extracted bilaterally. 12 weeks later, 2 implants with a TPS surface were placed in one side and 2 implants with a machined surface were placed in the contralateral side. Twelve weeks after implant installation, crowns, connected in pairs with orthodontic expansion screws, were fitted to the implants and a 0.6 mm wide expansion was initiated. Clinical registrations, standardized radiographs and fluorochrome labeling were carried out during a 24-week period of loading. Biopsies with the implants in situ were harvested and processed for ground sectioning. The sections were subjected to histologic and histometric examination. A higher marginal bone level was observed around implants with a TPS surface compared to machined implants. Furthermore, the values describing the amount of bone-to-implant contact at the bone/implant interface as well as the density of the peri-implant bone were lower at the machined than at the TPS implants.

Bone reactions adjacent to titanium implants subjected to static load. A study in the dog (I).

The aim of the study was to evaluate the effect of lateral static load induced by an expansion force on the bone/implant interface and adjacent peri-implant bone. In 3 beagle dogs, the 2nd, 3rd and 4th mandibular premolars were extracted bilaterally. Twelve weeks later 8 implants of the ITI Dental Implant System were placed in each dog. Crowns connected in pairs were screwed on the implants 12 weeks after implant installation. The connected crowns contained an orthodontic expansion screw yielding 4 loading units in each dog. Clinical registrations, standardized radiographs and fluorochrome labeling were carried out during the 24-week loading period. Biopsies were harvested and processed for ground sectioning. The sections were subjected to histological examination. No evident marginal bone loss was observed at either test or control sites. The bone density and the mineralized bone-to-implant contact were higher adjacent to the lateral loaded implants than at the unactivated control sites. It is suggested that the static load applied to implants in a lateral direction resulted in a structural adaptation of the peri-implant bone.

Implant-supported overdentures, a prevention of bone loss in edentulous mandibles? A 5-year follow-up study.

UNLABELLED: The purpose of this study were to analyse 1) the changes in the bone mineral content (BMC) in mandibles with implant-supported overdentures when compared with the physiologic age-related mandibular BMC loss, 2) whether the BMC changes were different in groups without or with a bar connecting the implants and 3) whether the presence of mandibular osteoporosis affects the loss of bone height around the implants. The material consisted of 22 long-term edentulous healthy persons, 18 women and 4 men from 54 to 78 years of age with 1 Astra Tech Dental Implant in both canine regions, connected by a bar in half of the patients. BMC measurements were performed in vivo by dual-photon scanner at baseline, just after attachment insertion, at 2-year and 5-year visits. Mandibular osteoporosis was estimated by comparing baseline BMC values with normal mandibular BMC values for young adults of same gender. Loss of bone height around implants was measured on periodically identical intraoral radiographs. The fixed parts of the implant-system were stable during the trial in all patients. IN CONCLUSION: 1) the increased function after this treatment seems to cause a load-related bone formation which minimizes the physiologic age-related mandibular BMC loss, 2) this effect seems to be independent of attachment system and 3) mandibular osteoporosis prior to implant treatment may be a risk factor for bone loss around implants. However, this treatment can be recommended also in osteoporotic persons.

Implant-supported mandibular overdentures retained with ball or bar attachments: a randomized prospective 5-year study.

PURPOSE: The aim of the present study was to evaluate the periimplant conditions and the maintenance requirements for implant-supported overdentures in the mandible retained with ball or bar attachments during a 5-year period. MATERIALS AND METHODS: Twenty-six completely edentulous patients had two Astra Tech dental implants placed in the anterior part of the mandible. The denture attachment system for the patients was chosen randomly by drawing lots. Eleven patients drew the bar attachment system and fifteen patients drew the ball attachment system. Plaque Index, Gingival Index, and probing pocket depth were assessed around each implant. Periotest values were recorded, and periodically identical intraoral radiographs were obtained with a specially designed film-holding device. RESULTS: No implants were lost from baseline to the 5-year registration. The periimplant conditions were very healthy after 5 years. No significant differences of the periimplant variables were recorded between the bar and the ball groups. During the first year of function, significantly more complications/repairs were registered in the bar group than in the ball group. In the following years, no significant differences were registered. The mean frequency of complications/repairs per patient per year was 1.0 in the bar group and 0.6 in the ball group during the 5-year observation period. CONCLUSION: Two implants with ball or bar attachment supported an overdenture in the mandible for 5 years with a 100% survival rate. No differences in marginal bone loss or health of the periimplant mucosa were observed between bar and ball attachment, but the frequency of technical complications/repairs per patient was higher around bar than ball attachments.

Anchorage of titanium implants with different surface characteristics: an experimental study in rabbits.

PURPOSE: To compare the anchorage of titanium implants with different surface roughness and topography and to examine histologically the peri-implant bone after implant removal. MATERIALS AND METHODS: Screw implants with five different surface topographies were examined: (1) turned ("machined"), (2) TiO2-blasted with particles of grain size 10 to 53 microns; (3) TiO2-blasted, grain size 63 to 90 microns; (4) TiO2-blasted, grain size 90 to 125 microns; (5) titanium plasma-sprayed (TPS). The surface topography was determined by the use of an optical instrument. Twelve rabbits, divided into two groups, had a total of 120 implants inserted in the tibiae. One implant from each of the five surface categories was placed within the left tibia of each rabbit. By a second operation, implants were installed in the right tibia, after 2 weeks in group A and after 3 weeks in group B. Fluorochrome labeling was performed after 1 and 3 weeks. Removal torque (RMT) tests of the implants were performed 4 weeks after the second surgery in group A and 9 weeks after the second surgery in group B. Thus, in group A, two healing groups were created, representing 4 and 6 weeks, respectively. The corresponding healing groups in group B were 9 and 12 weeks. The tibiae were removed, and each implant site was dissected, fixed, and embedded in light-curing resin. Ground sections were made, and the peri-implant bone was analyzed using fluorescence and light microscopy. RESULTS: The turned implants had the lowest Sa and Sy values, whereas the highest scores were recorded for the TPS implants. The corresponding Sa and Sy values for the TiO2-blasted implants were higher when a larger size of grain particles had been used for blasting. At all four observation intervals, the TPS implants had the highest and the turned implants the lowest RMT scores. The differences between the various TiO2-blasted implants were, in general, small, but the screws with the largest Sa value had higher RMT scores at 6, 9, and 12 weeks than implants with lower Sa values. The histologic analysis of the sections representing 6, 9, and 12 weeks revealed that fractures or ruptures were present in the marginal, cortical peri-implant bone. In such sections representing the TPS and TiO2-blasted implant categories, ruptures were frequently found in the zone between the old bone and the newly formed bone, as well as within the newly formed bone. CONCLUSIONS: The present study demonstrated that a clear relation exists between surface roughness, described in Sa values, and implant anchorage assessed by RMT measurements. The anchorage appeared to increase with the maturation of bone tissue during healing.

A 2-year report on maxillary and mandibular fixed partial dentures supported by Astra Tech dental implants. A comparison of 2 implants with different surface textures.

In 50 partially edentulous patients, 133 (48 maxillary; 85 mandibular) Astra Tech dental implants of 2 different surface textures (machined; TiO-blasted) were alternately installed, supporting 52 fixed partial dentures (FPDs). Before abutment connection 2 machined implants (1 mandibular; 1 maxillary) were found to be non-osseointegrated and were replaced. Another implant could not be restored due to a technical complication. Two FPDs were remade because of technical complications, both because of abutment fractures. Thus, after 2 years in function, the cumulative survival rates were 97.7% and 95.7% for implants and prostheses, respectively. There was no statistically significant difference in survival rate between the 2 types of implants, 100% (TiO-blasted) vs 95.3% (machined), P = 0.24. After 2 years in function, when both jaw and type of implants were combined, the mean (SD) marginal bone loss was 0.24 (0.69) mm. No statistically significant difference in bone loss was found between the 2 types of implant after 2 years of loading, 0.04 (0.82) mm, P > 0.30.