Comparative Evaluation of Survival Rates and Marginal Bone Levels of Nonsplinted Immediately Loaded Interforaminal Mandibular Implant-Retained Overdentures: A Randomized Controlled Clinical Trial with 5-Year Results.

PURPOSE: Τo evaluate and compare the marginal bone loss (MBL), survival rates, and periodontal parameters of immediately loaded implants with either Dolder bar or Locator attachments placed in the interforaminal region of edentulous mandibles. MATERIALS AND METHODS: A total of included 19 patients with edentulous mandibles each received two implants in the interforaminal area of the symphysis. Randomly allocated Dolder bar or Locator attachments were then attached immediately, and both clips and a framework were fastened to the denture by the dental laboratory within 24 hours. RESULTS: A total of 28 subjects with 56 implants were treated in accordance with the immediate-loading study protocol. Of these, 9 patients were lost to follow-up; 1 patient reported a serious illness and 8 patients moved and couldn't be reached. The 19 subjects not lost to follow-up (11 women and 8 men; average age: 68 years) were included. Every patient received either two Locator abutments and were assigned to group A (7 patients; 36.8%) or two multiunit abutments and were assigned to group B (12 patients; 63.2%). No implant failure was detected for either group, and therefore the survival rate for both groups was 100% after 5 years. After 5 years without any symptoms, 2 implants from group A and 7 implants from group B showed > 2 mm of MBL, which makes the group A success rate 85.7% and the group B success rate 70.8%. Modified sulcular bleeding index (mSBI) did not differ significantly at any of the measurement intervals. However, the modified plaque index (mPI) of group B was significantly higher than group A at the 60-month follow-up. CONCLUSION: It can be concluded that either splinting or not splinting the immediately loaded interforaminal implants to retain mandibular overdentures (OVDs) does not affect marginal bone levels after 5 years and immediate loading of nonsplinted implants with Locator attachments can be safely preferred to retain mandibular OVDs.

The "Tunneled Sandwich" Technique for Preserving the Buccal Tissue Volume After Immediate Implantation: A Retrospective Report of 10 Cases.

Tooth loss or extraction is associated with significant reduction in alveolar ridge volume, extensively expressed in the anterior zone, and immediate implant placement is insufficient to overcome this problem. The proposed approach combined immediate implant placement with buccal tissue enhancement by applying a crosslinked collagen matrix hydrated with crosslinked hyaluronic acid (xHyA). All 10 cases presented with a retained but narrow buccal socket wall, so immediate implant placement with the "tunneled sandwich" technique was performed after tooth extraction. The tunneled sandwich technique helped create a subperiosteal pouch for insertion of the collagen matrix buccal to the alveolar bone crest. The implants healed transmucosally by receiving either a gingiva former or an immediate temporary restoration. Ten sites in 10 patients demonstrated stable, noninflamed peri-implant conditions and suitable ridge volume at the implant neck and achieved high pink esthetic scores 6 months after implant loading. The tunneled sandwich technique is a suitable method to preserve buccal volume, which biologically and esthetically contributes to favorable long-term results.

Determination of intercanine distance from a proportion calculation: A pilot clinical study.

STATEMENT OF PROBLEM: The optimal positioning of artificial teeth is essential for long-term success when providing removable complete dentures. However, information about the original tooth positions may be lacking, especially the canine teeth, which play a key role in the tooth arrangement. PURPOSE: The purpose of this pilot clinical study was to determine if the mandibular and maxillary canine position can be determined by proportioning to certain anatomic landmarks. MATERIAL AND METHODS: Fifty participants (32 women, 18 men) with a mean age of 19.18 years and Angle class 1 and 2 malocclusions were selected randomly from patients who had completed their orthodontic treatment. The distance between the sagittally bisecting lines of the maxillary tuberosity and the distance between the sagittal bisecting lines of the retromolar pads in the mandible were measured from casts and recorded in millimeters. The expected distances between the canine cusps in both jaws (e-DCCmand and e-DCCmax) were calculated, and the distance between the canine cusps in both jaws (DCCmand and DCCmax) was measured. The measurements and the calculated expectation values for maxillary and mandibular cast models were recorded and statistically compared. RESULTS: The mean ±standard deviation value of the maxillary intercanine distance was 35.5 ±1.4 mm, and the calculated value was 35.52 ±1.43 mm. In the mandible, the mean ±standard deviation value of the mandibular intercanine distance was 26.73 ±1.25 mm, and the calculated value was 26.69 ±1.33 mm. The difference between the means of expected DDC for the maxilla and mandible was within the equivalence interval (P<.001). CONCLUSIONS: The proportions evaluated were determined to provide accurate canine positions and should be suitable for use in the treatment of edentulous patients.

Microcirculation and neutrophil-related cytokine concentrations are not altered around narrow diameter implants in T2DM patients during wound healing.

OBJECTIVES: The aim of this study was to assess the microcirculation and the expression patterns of wound-healing-related cytokines around narrow-diameter implants in type 2 diabetes mellitus (T2DM) and normo-glycemic patients. MATERIALS AND METHODS: A total of 31 patients, 16 of which diagnosed with T2DM (HbA1c > 6.5) and 15 normo-glycemic patients, received narrow diameter implants in the posterior mandible or maxilla. During the 3-month healing period, soft-tissue perfusion was monitored via laser Doppler flowmetry. Peri-implant fluid (PICF) was harvested and analyzed for concentrations of interleukin-1ß (IL-1ß), interleukin-23 (IL-23), interleukin-17 (IL-17), and granulocyte colony-stimulating factor (G-CSF) by a multiplex, bead-based immunoassay. RESULTS: Microcirculatory perfusion patterns during wound healing exhibited no significant differences throughout the observation period. IL-1ß concentrations were expectedly elevated during the early phases of wound healing. At the first visit after surgery, IL-23 concentrations were significantly higher in implants of diabetic patients. This difference was diminished over the course of the observation period. For the other tested analytes, no differences were observable between both groups. CONCLUSION: Wound healing after implant surgery was similar in T2DM and healthy patients. Hydrophilic-surface titanium-zirconium implants with reduced diameter may be considered for implant therapy of diabetes mellitus type II patients. REGISTRATION NUMBER: NCT04630691 (clinicaltrials.gov).

Adjunctive Application of Hyaluronic Acid in Combination with a Sodium Hypochlorite Gel for Non-Surgical Treatment of Residual Pockets Reduces the Need for Periodontal Surgery-Retrospective Analysis of a Clinical Case Series.

The comprehensive treatment of periodontitis stage 2 to 4 aims at the resolution of periodontal inflammation and "pocket closure", which implies a residual probing depth of ≤4 mm and a negative BoP. However, supportive periodontal therapy (SPT) regularly leaves behind persistent periodontal pockets with 5 or more mm in residual PPD and sites that often re-colonize and re-infect. Various adjunctive options for subgingival instrumentation have been proposed to enhance the antimicrobial effects to better control the re-infection of these residual sites. The locally applied adjuncts, based on their anti-inflammatory effect, are sodium hypochlorite antiseptic cleaning gel and cross-linked hyaluronic acid (xHyA). Both recently moved into the focus of clinical research on non-surgical and surgical therapy for periodontitis. The surgical use of xHyA indicates regenerative potential, supporting periodontal regeneration. This case series retrospectively analyzes the clinical benefits of the consecutive flapless application of sodium-hypochlorite-based cleaning gel and xHyA at the SPT to achieve pocket closure, thereby reducing the need for periodontal surgery. In 29 patients, 111 sites received the treatment sequence. At 6-month re-evaluation, an overall PPD reduction exceeding 2 mm was achieved, associated with a similar CAL gain (2.02 mm); the bleeding tendency (BoP) was reduced by >60%. Pocket closure occurred in almost 25% of all the sites. Within their limits, the present data suggest that the proposed combined adjunctive treatment of residual active periodontal sites yielded significant improvement in the clinical parameters. Further studies in RCT format are required to confirm these observations.

Implant stability of narrow diameter implants in hyperglycemic patients-A 3-month case-control study.

OBJECTIVES: The aim of this prospective case-control study was to compare the development of implant stability quotients of narrow diameter implants in patients with type 2 diabetes mellitus (T2DM) and healthy individuals within the first 3 months after implant insertion. METHODS: Sixteen patients with T2DM (HbA1C > 6.5%) as test group and 16 nondiabetic patients (HbA1C < 5.9%) as the control group were evaluated. All patients received narrow-diameter tissue level implants in an edentulous area posterior to the canine. The implant stability was measured by means of resonance frequency analysis after 3 days, 7 days, 4 weeks, and 3 months postplacement. Statistical analysis of intergroup differences and correlation to HbA1c values and treated jaw was performed in PRISM 8. RESULTS: The means for implant stability quotients showed a significant increase between Day 3 and 3-month assessment in both groups. No significant differences between study groups and no correlation of implant stability to HbA1c were found. CONCLUSION: The present study shows encouraging clinical outcomes for narrow-diameter implants inserted in the posterior zone in patients with uncontrolled T2DM.

Tooth-Derived Granules in Combination with Platelet-Rich Fibrin ("Sticky Tooth") in Socket Preservation: A Histological Evaluation.

BACKGROUND: The maintenance of ridge volume following tooth extraction has gained more importance in the last few years. This clinical study aimed to assess the impact of autologous dentin particles mixed with injectable platelet-rich fibrin (i-PRF) on a sticky tooth mixture for socket preservation in terms of consecutive need for horizontal guided bone regeneration and histological findings. METHODS: Eight extraction sockets in seven patients were included in this study. Autologous dentin particles were mixed with PRF, filled in the sockets, and covered with a cross-linked collagen membrane exposed to the oral cavity and fixated by crisscross sutures. An orthopantomogram was taken before the first surgical procedure and a CBCT prior to static computer-aided implant surgery. At the time of implant placement, cores were harvested with the aid of a trephine for histological examinations for every preserved socket. RESULTS: No further horizontal GBR intervention was required in any cases, and the histological findings were unremarkable. The new bone was mostly cancellous and in direct contact with the remaining dentin granules. CONCLUSIONS: Within the limits of this clinical study, it may be concluded that this method is valuable for socket preservation and obtaining vital and good quality bone structure. The sticky tooth technique seems to be very efficient despite the more complex equipment.

Comparison of Marginal Bone Levels Around Tissue-Level Implants with Platform-Matched and Bone-Level Implants with Platform-Switching Connections: 1-Year Results of a Prospective Cohort Study with a Split-Mouth Design.

PURPOSE: This clinical study was conducted to compare the influence of a platform-switched bone-level implant and a platform-matched tissue-level implant on marginal bone loss during the first year after loading. MATERIALS AND METHODS: Edentulous subjects who applied for two-implant-retained mandibular overdentures and showing sufficient bone volume for implants with 4.3-mm diameter and 12-mm length were enrolled. For standardization reasons, all subjects received a platform-matched tissue-level implant and a platform-switched bone-level implant in the anterior mandible. Since implants from the same manufacturer were used, both implants had identical implant thread designs and surface properties. All subjects received two-implant-retained mandibular overdentures with opposing maxillary complete dentures, and the implants were loaded after 6 weeks. Marginal bone loss was monitored via panoramic radiographs obtained immediately after loading and at the 6- and 12-month recalls after implant loading, and periodontal parameters, such as pocket probing depths, Plaque Index scores, and bleeding on probing, were also measured and recorded. RESULTS: Twenty-six patients received 26 bone-level and 26 tissue-level implants. No statistically significant differences were detected between the bone loss of the two groups for all the measurements (P > .05). Additionally, no significant difference was detected between the measured periodontal parameters of the two groups (P > .05). CONCLUSION: Within the limitations of this prospective clinical study with a follow-up time of 12 months, it can be concluded that the platform-switching bone-level design and the platform-matching tissue-level design show similar bone loss in the anterior edentulous mandible.

One-year performance of posterior narrow diameter implants in hyperglycemic and normo-glycemic patients-a pilot study.

OBJECTIVES: The aim of the study was to compare the performance of narrow diameter implants in patients with uncontrolled diabetes mellitus type 2 (T2DM) and normo-glycemic individuals during the first 12 months after implant loading. MATERIAL AND METHODS: In 16 T2DM patients with HbA1C > 6.5% (test group) and 16 normo-glycemic patients (HbA1C < 6.0%; control group), one to two narrow diameter tissue level implants were placed in the posterior maxilla or mandible. After 3-month lasting integration period, implants were loaded by fixed dentures. The clinical parameters probing depth (PD), bleeding on probing (BOP), attachment loss (CAL), recession and papilla bleeding index (PBI) were assessed manually at loading and after 12 months of function. The paired digital periapical radiographs were analyzed with regard to the change in marginal bone level (MBL) from baseline to 12 months' control. The mean values calculated for both patient groups were statistically analyzed. The technical complications were recorded. RESULTS: The T2DM group accounted 13 patients due to 3 dropouts. The overall implant survival rate after 12 months was 100%. The differences in means for the clinical parameters and the MBL were statistically non-significant between the T2DM and normo-glycemic patients for the short period of loaded function reported here. No technical complications were recorded. CONCLUSIONS: The study demonstrated an encouraging clinical outcome with narrow diameter implants in patients with uncontrolled T2DM compared to non-diabetics after 12 months post loading. For the short observation period, no biological and technical complications were reported regardless the glycemic status. CLINICAL RELEVANCE: Patients with HbA1C > 6.5% may benefit from the treatment with narrow diameter implants by avoiding complex surgical interventions with augmentation procedures. TRIAL REGISTRATION: Clinicaltrials.gov : NCT04630691.

The influence of the implant-abutment complex on marginal bone and peri-implant conditions: A retrospective study.

PURPOSE: The design of the implant-abutment complex is thought to be responsible for marginal bone loss (MBL) and might affect the condition of the peri-implant tissues. This the present study aimed to evaluate the influence of the implant-abutment complex on MBL and the peri-implant tissues in partially edentulous patients treated with dental implants and determine the most advantageous design. MATERIALS AND METHODS: A total of ninety-one endosseous implants with different designs of implant-abutment complex [tissue level-TL (n = 30), platform switch-PS (n = 18), and platform match-PM (n = 43)] were reviewed for MBL, Probing Pocket Depth (PPD) and Bleeding on Probing (BoP). MBL was calculated for first year of the insertion and the following years. RESULTS: The median MBL for the PM implants (2.66 ± 1.67 mm; n = 43) in the first year was significantly higher than those for the other types (P =.033). The lowest rate of MBL (0.61 ± 0.44 mm; n = 18) was observed with PS implants (P =.000). The position of the crown-abutment border showed a statisticallysignificant influence (P =.019) and a negative correlation (r=-0.395) on MBL. BoP was found significantly higher in PM implants (P =.006). The lowest BoP scores were detected in PS implants, but the difference was not significant (P =.523). The relation between PPD and connection type revealed no statistically significant influence (P >.05). CONCLUSION: Within the limitations of the present study, it may be concluded that PS implants seem to show better peri-implant soft tissue conditions and cause less MBL.

An In Vitro Evaluation of Primary Stability Values for Two Differently Designed Implants to Suit Immediate Loading in Very Soft Bone.

The achievement of sufficient implant stability in poor quality bone seems to be a challenge. Most manufacturers develop special dental implants, which are claimed to show higher stability even in very soft bone. The aim of this experimental study was to compare two recently introduced dental implants with differing thread designs. A total of 11 implants of each group were inserted in the part of the fresh bovine ribs, corresponding to very soft bone. The primary stability was measured with resonance frequency analysis (RFA) and Periotest; the average of two measurements for each method and for each implant was taken and statistical analysis was applied. The highest stability values were obtained with the ICX Active Master implants, followed by the Conelog® Progressive-Line implants placed with the very soft bone protocol. The primary stability values of the Conelog® Progressive-Line implants inserted by the very soft bone protocol and the ICX Active Master implants placed with the standard protocol showed sufficient stability for immediate loading in low-density bone. Within the limitations of this study, the thread design of the implants and underdimensioned implant bed preparation seem to be effective for better primary stability in cancellous bone.

GTR Treatment in Furcation Grade II Periodontal Defects with the Recently Reintroduced Guidor PLA Matrix Barrier: A Case Series with Chronological Step-by-Step Illustrations.

Molars with a furcation involvement (FI) exceeding grade 1 according to Hamp's classification are at approximately doubled risk of tooth loss. Guided tissue regeneration (GTR) is a regenerative approach in the treatment of periodontal defects and is aimed at achieving new clinical attachment formation. The aim of this case series was to assess the efficacy of a newly reintroduced polylactic acid (PLA) matrix barrier and to evaluate the feasibility of the surgical approach. 11 patients with an average age of 58.7 years were treated with GTR using a PLA matrix barrier. Patients were instructed not to brush and chew on the treated side for 4 weeks. A gentle clinical probing was performed after 6 months for the first time after surgery. The patients were included into individual maintenance program at three months' interval. The clinical improvement was expressed by reduced horizontal penetration of the probe accompanied by vast resolution of the vertical defect component. The change from grade II to grade I or complete resolution of the FI could be seen in 8 from 11 sites included. The newly reintroduced PLA matrix barrier showed promising results after a 12-month observation period with clinical attachment gain.

In vitro comparison of trueness of 10 intraoral scanners for implant-supported complete-arch fixed dental prostheses.

STATEMENT OF PROBLEM: Digital scanning systems have become popular, but whether these systems are adequate for complete-arch implant-supported fixed dental prostheses is unclear. PURPOSE: The purpose of this in vitro study was to evaluate the trueness of 10 different dental intraoral scanners. MATERIAL AND METHODS: Six implant analogs were installed, and an edentulous mandibular model composed of scannable Type 4 gypsum was scanned with 10 different intraoral scanners (3D Progress, Omnicam, Bluecam, Apollo DI, Planscan, E4D Tech, TRIOS MonoColor Cart, TRIOS Color Cart, TRIOS Color Pod, Lythos), 10 times each after the scan body was placed on the implant abutments. The data obtained were then converted into standard tessellation language format. For the control group, the gypsum model was scanned with an industrial scanner (ATOS Core 80). For trueness, the dental and industrial scanning data packs were analyzed with 3D comparison software. Statistical analyses were performed by using the Kruskal-Wallis and Mann-Whitney U tests. RESULTS: When ranked according to their surface superimposition values, the Color POD, Omnicam, Apollo DI, Color Cart, MonoColor Cart, and Bluecam scanners were found within the range of 31 to 45 µm. This group was followed by E4D, 3D Progress, Lythos, and Planscan, which were found within the range of 82 to 344 µm according to the same criteria. CONCLUSIONS: Some of the digital scanners had the necessary performance for the fabrication of complete-arch implant-supported fixed dental prostheses. However, the possibility of data loss producing artifacts should be considered.

Evaluation of two interforaminal implants and implant-assisted removable dentures on stress distribution: an in vitro study.

OBJECTIVES: In mandibular edentulism, the treatment option with a two-interforaminal implant-retained bridge and a removable partial denture is rarely evaluated in literature. The aim of this in vitro study was to evaluate the stress distribution of this treatment option by comparing it with traditional treatment options with interforaminal implants in the edentulous mandible. MATERIALS AND METHODS: Two interforaminal implants were placed in a formalin-fixed cadaver mandible, and overdentures with three different types of attachments were fabricated: (1) two ball attachments and an overdenture, (2) a Dolder bar and an overdenture, and (3) screw-retained two-implant inter-canine porcelain fused to a metal bridge and an implant-assisted removable denture (IARD) with precision attachments. Three biting conditions were generated for each denture type, and the strains were documented under vertical loading of 100 N. RESULTS: The calculated strain values from measured strains in all measurement sites and loading conditions for the screw-retained two-implant inter-canine porcelain fused to a metal bridge and a cast framework partial denture with precision attachments situation were lower than in the other scenarios (P<0.05). CONCLUSION: Within the limitations of the present study, it can be concluded that an IARD may be a reasonable and valuable alternative to ball attachments or a bar in two interforaminal implants, especially when the patients prefer to be able to show their teeth even when they take out their removable dentures.

Is clinical experience important for obtaining the primary stability of dental implants with aggressive threads? An ex vivo study

Background: The aim of this study was to investigate the clinicians' experience on maintaining the primary stability of implants with aggressive threads belonging to a novel dental implant system. Material and Methods: Three hundred implants with aggressive threads were inserted in fresh bovine ribs mimicking Type IV bone by five clinicians which were classified according to their previous experience of total number of implant insertion. An independent examiner measured the primary stability of all implants after insertion by using resonance frequency analysis (RFA), electronic percussive testing (EPT) and removal torque methods. Results: No significant differences were detected between the stability values measured by the clinicians (p> 0.05) except the Periotest values (PTVs) of the non-experienced clinician. PTVs of the non-experienced clinician were significantly higher than the PTVs of the expert and good clinicians (p<0.05). Significantly higher stability values were detected in the secondary insertion of the non-experienced clinician as compared to her initial insertion values (p<0.05). No significant differences were detected between the first and second measurements of the other clinicians (p> 0.05). Conclusions: Within the limitations of this ex-vivo study, it may be concluded that experience does not play an important role in maintaining the stability of implants with aggressive threads

No disponible

Effect of Over-the-Counter Topical Agents on Denture-Induced Traumatic Lesions: A Clinical Study.

PURPOSE: To investigate the effects of over-the-counter products on the healing of denture-induced ulcerations and patients' self-reported pain. MATERIALS AND METHODS: A total of 140 patients with acute denture-induced ulcerations were randomized into seven treatment groups: denture grinding (control); topical application of corn oil gel (placebo); triester glycerol oxide gel; D-panthenol gel; D-panthenol mouthwash; L-arginine mouthwash; and hyaluronic acid gel. Healing and self-reported pain were assessed after 1, 3, and 7 days of treatment. RESULTS: The percentage of healed lesions in the mandible and maxilla after 7 days was 67% and 65%, respectively. The only significance in healing was for mandibular lesions at 3 days after application of L-arginine mouthwash; at this period, the healing rate was significantly higher than d-panthenol gel, d-panthenol mouthwash, and hyaluronic acid gel (P < .05). CONCLUSION: Denture grinding as the current protocol for acute denture-induced ulcerations should remain as the default.

Evaluation of volumetric wear of abutments on the retention loss of ball attachment systems in implant-retained overdentures: An in vitro study.

BACKGROUND: There is a lack of studies evaluating the wear of the male components of the ball attachment systems of implant-retained overdentures. PURPOSE: The purpose of this study was to compare the volumetric wear patterns four commercially used ball abutments. MATERIALS AND METHODS: Forty-eight identical polyethylene and acrylic blocks were fabricated and four groups consisting of 12 polyethylene blocks with two implants and 12 acrylic blocks, which were used as overdentures, were generated (two groups with plastic females, one group with gold and one group with titanium females). Every specimen underwent 5000 insertion and removal cycles (~4.5 years) and retention forces were measured. For the evaluation of volumetric wear, all the ball abutments were scanned before and after the 5000 cycles using a three-dimensional scanner and the data were analyzed using the software supplied by the manufacturer. RESULTS: Statistically significant retention force differences were observed between the groups at each cycle (P < .05). Among the four groups, retention force was lowest in the group with titanium females (5.59 ± 2.27) and highest in the group with gold females (43.0 ± 6.3) at the end of 5000 cycles. Statistically significant dimensional changes in the male components were observed between the groups (P < .05). Volumetric losses were 11%-13% in Group I and II, 1% in Group III, and 25% in Group IV. Group III showed significantly lower volumetric wear whereas Group IV showed significantly higher volumetric wear than all the other groups (P < .001). No significance was detected between Group I and II (P > .05). CONCLUSION: Within the limitations, it can be concluded that although clinical studies are needed to ensure the findings of the present study, due to severe retention loss and volumetric abutment wear, ball attachments with titanium female components should be used with caution.

Clinical Comparison of Screw-Retained and Screwless Morse Taper Implant-Abutment Connections: One-year Postloading Results.

PURPOSE: The purpose of this study was to clinically evaluate the screwless Morse taper implant-abutment connection type, in which the retention screw is totally eliminated, in terms of stability, success, periodontal parameters, and marginal bone levels after 1 year of function by comparing it with a passive fit internal implant-abutment connection, wherein a space exists between the matching components. MATERIALS AND METHODS: Each edentulous subject received an implant with a screwless Morse taper connection (MT) in the left canine area of the mandible and an implant with a screw-retained implant-abutment connection (SR) in the right canine area of the mandible. All implants were loaded 6 weeks later. All cases were restored with a cemented bar-retained mandibular overdenture opposing a maxillary complete denture. Clinical recalls at 6 months and 12 months postloading were scheduled and the MT and SR implants were compared in terms of success, survival, primary and secondary implant stability, marginal bone loss, soft tissue response, and mechanical complications. The results were statistically analyzed. RESULTS: A total of 20 subjects were included (10 females, 10 males; average age: 61.60 years) and a total of 40 implants were inserted. No implant failure or technical problem was detected for either MT or SR implants. Marginal bone loss around MT and SR implants did not show any significant differences at 6 weeks after surgery (time of loading) or at 6 months or 12 months postloading (P > .05). Periodontal parameters such as gingival index and probing pocket depth of MT and SR implants likewise did not differ significantly at 6 months and 12 months postloading (P > .05). Primary stability values of MT and SR implants did not differ significantly when measured with the insertion torque device (mean of 68.10 Ncm for MT and 64.20 Ncm for SR implants; P = .564), nor when measured with the electronic percussive testing device (mean of -5.30 for the MT and -5.35 for the SR implants; P = .398). However, MT implants showed lower stability at the time of loading (6 weeks) and 6 months postloading (P = .037 and P = .003, respectively). Stability values did not show any significant differences 12 months postloading (P > .05). CONCLUSIONS: Within the limitations of this clinical study, it can be concluded that implants with screwless Morse taper and passive fit internal connections show comparable technical and biologic results after 1 year of function.

Influence of the Localization of Frontal Bone Defects on Primary Stability Values of 2 Different Implant Designs: An In Vitro Study.

OBJECTIVES: The aim of this study was to determine the influence of different frontal bone defect localizations on primary stability values of 2 different implant designs. MATERIALS AND METHODS: Eight cow rib segments were prepared before implant installation, as 2 segments with coronal, 2 with middle, and 2 with apical defects and 2 with control. Thirty-two cylindrical and 32 tapered implants were placed in the remaining 4 segments. Implant stability measurements were performed using electronic percussive testing and resonance frequency analysis. RESULTS: No significance was detected between the stability values of the 2 implant designs except the implant stability quotient (ISQ) of control groups. The tapered implants control group showed significantly higher lateral ISQs compared with cylindrical implants (P = 0.033). For both implant types, stability values were significantly lower in coronal defects (P < 0.01). No significant differences were detected in other defect types. CONCLUSION: Within the limitations of this study, it may be concluded that coronal defects may influence primary stability negatively, compared with middle and apical defects. Although statistically not significant, coronal defects caused lower primary stability values with the tapered design compared with parallel design.

Comparison of the Primary Stability of Two Implant Designs in Two Different Bone Types: An In Vitro Study.

PURPOSE: Achievement of primary stability upon surgical placement of dental implants is a key factor for successful osseointegration and depends mainly on implant-related factors. The aim of this study was to compare and assess the primary stability of implants with active and regular threads in type 2 as well as type 4 bone. MATERIALS AND METHODS: Fresh cow vertebrae and a pelvis were used as models of type 4 bone and type 2 bone, respectively. Implants with two different designs-regular-threaded and active-threaded-both 4.3 mm wide and 13 mm long, were placed in both types of bone (n = 80). Stability measurements were completed by four prosthodontists using two different Periotest devices and resonance frequency analysis. Statistical analyses were performed with the Mann-Whitney U test. RESULTS: No statistically significant differences were found between the implant types in either type of bone in the stability measured with different methods. For both implant types, the mean resonance frequency values in type 2 bone were statistically significantly higher than in type 4 bone, whereas the mean Periotest values in type 2 bone were statistically significantly lower than in type 4 bone. CONCLUSION: Within the limitations of this in vitro study in bone types 2 and 4, the active-threaded implant, which was invented to increase primary stability, did not show higher primary stability compared to a regular-threaded implant.