Mean Marginal Bone Resorption Research Articles

Effects of Implant Diameter on Implant Stability and Osseointegration in the Early Stage in a Dog Model.

Purpose: To determine the optimal implant diameter under limited bone width by comparing the effects of implants with different diameters on implant stability, peri-implant bone stability, and osseointegration. In addition, to evaluate the reliability of resonance frequency analysis (RFA) in detecting osseointegration and marginal bone level (MBL). Materials and Methods: Mandibular premolars and first molars of seven beagle dogs were extracted. After 8 weeks, their mandibular models and radiographic information were collected to fabricate implant templates. Implant sites were randomly divided into three groups according to diameter: Ø3.3, Ø4.1, and Ø4.8 mm. Implant stability quotient (ISQ) measurement and radiographic evaluation were performed after surgery (baseline) and at 4, 8, and 12 weeks. Three dogs were euthanized at 4 weeks to observe osteogenesis and implant-tissue interface biology. Four dogs were euthanized at 12 weeks to observe osseointegration. Hard tissue sections were prepared to analyze osteogenesis (fluorescence double labeling) and osseointegration (methylene blue-acid fuchsin staining). Results: At baseline and at 4, 8, and 12 weeks, the ISQ values of Ø4.1- and Ø4.8-mm implants did not differ (P > .05), but both had higher values than the Ø3.3-mm implants (P < .05). The mean marginal bone resorption (MBR) associated with Ø3.3-, Ø4.1-, and Ø4.8-mm implants was 0.65 ± 0.58 mm, 0.37 ± 0.28 mm, and 0.73 ± 0.37 mm, respectively. The buccal MBR of Ø4.8-mm implants was significantly higher than that of Ø4.1-mm implants (P < .05). The bone-to-implant contact (BIC) percentage at 12 weeks did not differ for any group (P > .05). The correlation coefficients between the ISQ and MBL of the Ø3.3-, Ø4.1-, and Ø4.8-mm implants were -0.84 (P < .01), -0.90 (P < .001), and -0.93 (P < .001), respectively, while that between the ISQ and BIC was 0.15 (P > .05). Conclusions: During the early healing stage, the performance of Ø4.1- and Ø4.8-mm implants in terms of implant stability was better than that of Ø3.3-mm implants. Implant diameter may not influence BIC percentage. RFA can be used to evaluate implant stability and MBL but is not suitable to assess the degree of osseointegration.

Implant–Prosthetic Rehabilitation of Maxillary Lateral Incisor Agenesis with Narrow Diameter Implants and Metal–Ceramic vs. All-Ceramic Single Crowns: A 16-Year Prospective Clinical Study

The main objectives of the present prospective clinical study were to evaluate the marginal bone resorption and the peri-implant soft tissue conditions around narrow diameter implants, as well as the clinical performances of metal–ceramic and all-ceramic single crowns in the implant–prosthetic treatment of maxillary lateral incisors agenesis. Seventy-two patients affected by monolateral or bilateral agenesis of the maxillary lateral incisors were included in the study, and a total of 105 narrow diameter implants were inserted. The final single crowns were fabricated 4 months after the surgical procedures by means of either titanium abutments with Auro-Galvan Crowns (AGC) veneered with feldspathic ceramics or zirconia abutments with all-ceramic (alumina or zirconia) crowns layered with dedicated veneering ceramics. Both marginal bone resorption and soft tissue quality were evaluated after a maximum period of 16 years. Two independent survival curves for patients wearing AGC or all-ceramic crowns were calculated by means of Kaplan–Meier analysis, and a log-rank test was performed in order to compare these curves (p &lt; 0.05). After 16 years of clinical function, a mean marginal bone resorption of 1.2 ± 0.61 mm and good response of peri-implant soft tissues were observed. Descriptive statistics resulted in 80% and 87.1% cumulative success rates for patients provided with AGC prostheses onto titanium abutments and all-ceramic crowns on-to zirconia abutments, respectively. The cumulative survival rate calculated for AGC group was 93.3%, whereas all-ceramic group showed a cumulative survival rate of 95.7%. No statistically significant differences were found with the log-rank tests. The overall success and survival rates calculated were 85% and 95% for all the restorations, respectively. Mucositis, abutment unscrewing, loss of retention, chipping, core fracture, and esthetic failure were the major complications reported. The implant–prosthetic approach can be considered an effective and viable solution to treat cases of maxillary lateral incisor agenesis in the long term.

Influence of apico-coronal positioning of tissue-level implants on marginal bone stability during supracrestal tissue height establishment: A multi-center prospective study.

Supracrestal tissue height establishment is a crucial factor influencing peri-implant marginal bone modifications prior to prosthesis delivery. If mucosal thickness is insufficient, peri-implant marginal bone resorption occurs to allow appropriate supracrestal tissue height formation. This study evaluates if marginal bone resorption occurring around tissue-level implants before prosthetic loading could be compensated by adapting apico-coronal positioning to mucosal thickness. Patients requiring placement of one single implant in the posterior mandible were treated with tissue-level implants with a 3-mm high transmucosal machined component and moderately rough implant body. Based upon vertical mucosal thickness measured after buccal flap reflection, implants were placed with the treated part: (group 1) 2 mm below crestal level in presence of thin mucosa (<2.5 mm); (group 2) 1 mm below the crestal level in presence of medium mucosa (2.5-3.5 mm); (group 3) at equicrestal level in presence of thick mucosa (>3.5 mm). Forty-nine implants, placed in 49 patients were included in final analysis (group 1: 18 implants; group 2: 16 implants; group 3: 15 implants). Mean marginal bone resorption after 5months of healing was 0.66 ± 0.49 mm, 0.32 ± 0.41 mm, and 0.22 ± 0.52 mm in groups 1, 2, and 3, respectively. Inter-group analysis highlighted significant differences between the three groups after ANOVA test (p=0.025). However, adaptation of apico-coronal implant positioning in relation to mucosal thickness, allowed to avoid early exposure of the treated surface in 100%, 93.7%, and 53.3% of the implants in groups 1, 2, and 3, respectively. During supracrestal tissue height formation, tissue-level implants inserted adapting apico-coronal positioning in relation to mucosal thickness exhibited greater marginal bone resorption at sites with thin mucosa than at sites with medium or thick mucosa. However, anticipating supracrestal tissue height establishment by adapting apico-coronal implant positioning in relation to mucosal thickness may effectively prevent unwanted exposure of treated implant surface.

Implant treatment after traumatic tooth loss: A systematic review.

Treatment after traumatic tooth loss is challenging and is currently guided by expert opinion and the individual patient situation. The aim of this study was to provide an overview on the outcome of dental implant treatment in the anterior maxilla after traumatic tooth loss, based on a systematic review of the existing evidence. A systematic search of the literature was performed on PubMed, Cochran Library and Web of Science following the PRISMA guidelines based on a structured research question (PICO). All clinical studies of five patients or more with follow-up of at least 1year after implant loading were included. Patients were at least 18years of age. Cohen's Kappa-coefficient was calculated. The Newcastle-Ottawa Scale was applied to assess the quality of the included studies. Descriptive statistical methods were applied. Nine hundred and ninety-nine articles were identified through the systematic search. Finally, six articles were eligible for inclusion. The studies comprised prospective and retrospective cohort studies and case series. From these, 96 patients with 120 implants were included. The age ranged from 18 to 59years. The survival rates of implants and superstructures were 97% and 95%, respectively, after a mean follow-up of 3.5years. Mean marginal bone resorption was 0.56mm (range 0.21-1.30mm). Complication rates were 7% and 11% on implant and superstructure level, respectively. Patient-reported outcome measures and objective evaluations showed a high level of satisfaction with the aesthetic outcome. Bone augmentation was performed in 60 implant sites. Three patients underwent pre-surgical orthodontic treatment. The maxillary central incisor was the most frequently replaced tooth (70%). This systematic review revealed a low level of evidence on the outcome of dental implant treatment after traumatic tooth loss. Systematic reporting of treatment outcomes of tooth replacements after dental trauma is highly encouraged to further guide dentists for the benefit of these challenging patients.

Does low gonial angle affect the Amount of Bone Loss Around implant in the posterior mandible?

Background: The purpose of this study was to investigate whether there is a role of the low gonial angle on marginal bone resorption around the implants placed in the posterior mandible. Methods: This retrospective study, including 20 patients with 46 implants followed 36 months were inserted in the toothless posterior area. Patients without systemic disease were included in this study. The gonial angle was measured on a panoramic x-ray; Patients with a gonial angle of more than 1250were classified as high gonial angle, and those with less than 1200 were classified as a low gonial angle group. Mesial and distal marginal bone resorption and implant angulation with the occlusal plane were measured via Image J software (National Institutes of Health; version 1.5i, USA). Independent samples t-test was used to compare measured variables between high and low gonial angle groups. Results: The mean marginal bone resorption (MBL) was 0.27±0.16 mm for the mesial side and 0.27±0.13mm for the distal side in the LGA group. In the HGA group, MBL was 0.77±0.28mm for the mesial side and 0.71±0.27mm for the distal side. There was no statistical significance between HGA and LGA groups regarding marginal bone resorption. However, implant angulation with the occlusal plane was correlated with marginal bone resorption in the HGA group. Conclusion: The result of this study is that a low gonial angle is not directly a risk factor for marginal bone resorption around the dental implant. However, implants should be placed perpendicular to the occlusal plane as possible in the HGA group.

A retrospective case series report on a novel aggressively threaded and tapered implant

Background: Firm primary implant stability is considered as one determinant of success with implant therapy. A novel tapered implant with aggressive threading aiming at high primary stability, also in low bone densities, using a simplified drilling protocol has recently been developed. Aim/Hypothesis: To retrospectively evaluate the primary stability, clinical and radiographic performance of 25 tapered and aggressively threaded implants in 15 consecutive patients after one year of follow-up. Materials and Methods: The study comprised of the first 15 consecutive patients (13 female, 2 male) treated with 25 implants (Proactive Edge, Neoss AB, Gothenburg, Sweden) using a one-stage protocol and loaded for at least one year (Figures 1 and 2). Five implants had been placed in the mandible and 20 in the maxilla for seven single tooth replacements, seven partial bridges and one full bridge. Insertion torque/time curves were registered during placement with an Elcomed drilling unit (W&H Austria GmbH, Bürmoos, Austria). RFA measurements were taken after implant placement using a PenguinRFA instrument (IDSAB, Gothenburg, Sweden). The implants were either restored immediately (n = 5) or after 6 to 8 weeks of healing (n = 20). Marginal bone levels were evaluated in baseline and one-year intraoral radiographs. Results: All implants achieved firm primary stability as assessed with insertion torque (42.6 + 17.0 Ncm, range 13-80 Ncm) and RFA (76.9 + 3.7 ISQ, range 66-84 ISQ) measurements. Thirteen of the implants (all 3.5 mm in diameter) could be placed after the use of one spiral drill only. The remaining implants (4.0 mm, n = 10, 5.0 mm, n = 2) were placed after using two spiral drills. No implant was lost during the one-year of follow-up. The mean marginal bone resorption was 0.5 + 0.6 mm after one year. Conclusions and Clinical Implications: The present case series report showed that the novel implant and simplified drilling protocol resulted in firm primary implant stability. Promising clinical and radiographic outcomes were seen after one year. However, clinical studies including more patients and implants are needed. Keywords: dental implants, primary stability, clinical follow-up, case series Figure 1: The Neoss Proactive Edge implant in different diameters, Figure 2: Postoperative (left) and one-year (right) intraoral radiograph of one implant used for a maxillary molar replacement.

Retrospective clinical evaluation of implant-assisted removable partial dentures combined with implant surveyed prostheses

Statement of problemImplant-assisted removable partial dentures (IARPDs) have been proposed as a treatment option for partially edentulous patients. However, evidence regarding the outcome of implant-assisted removable partial dentures with implant surveyed prostheses is limited. PurposeThe purpose of this retrospective clinical study was to evaluate the clinical status and complications of IARPDs combined with implant surveyed prostheses in terms of clinical tissue condition, marginal bone resorption, and prosthetic complications. Material and methodsPatients treated with IARPDs combined with implant surveyed prostheses who had worn an IARPD for at least 12 months were included. Twenty-four participants (25 prostheses, 12 maxillary, and 13 mandibular) were evaluated, with 80 implants used as abutments for IARPDs. The average follow-up period was 27.6 months, and the maximum follow-up was 78 months. Implant cumulative survival rate, marginal bone resorption, probing depth, peri-implant inflammation, bleeding, plaque, calculus, and complications were evaluated. ResultsNo implant failure occurred, and all implants functioned without clinical mobility. Mean marginal bone resorption of implants at 1 year after loading was 0.77 ±0.63 mm, and mean probing depth was 3.4 ±0.1 mm. No patient developed peri-implantitis, and no implant failed. Two clasp fractures, 1 rest fracture, 1 decementation, and 1 fracture of porcelain on an implant surveyed prosthesis were detected at 12 months after loading. ConclusionsWell-planned IARPDs using implant surveyed prostheses were clinically successful. Longitudinal and systematic clinical studies are necessary to confirm these results.

FOUR IMPLANT SUPPORTED MANDIBULAR OVERDENTURES WITH RIGID TELESCOPIC ATTACHMENTS. A STUDY OF CIRCUMFERENTIAL BONE RESORPTION USING CONE BEAM COMPUTERIZED TOMOGRAPHY

Aim: This study aimed to evaluate circumferential bone resorption around implants supporting mandibular overdentures with rigid telescopic attachments. Materials and methods: Eight totally edentulous participants with adequate remaining bone mesial and distal to the mental foramen received four implants in canine and first molar areas of the mandible. After 3 months of osseointegration, telescopic attachments were connected to the denture. Marginal bone resorption was measured around canine and molar implants using Cone beam computerized tomography (CBCT) at base line, 6 months (6m), and 12 months (12m) after overdenture insertion. Results: The survival rate was 97% after one year. The mean marginal bone resorption at all implant surface combined together is 1.41±.54mm. Posterior implants were associated with significant higher marginal bone resorption than anterior implants for distal, lingual and mesial surfaces. The highest marginal bone resorption was noted at the lingual surface followed by mesial surface, then distal surface and the lowest marginal bone resorption was noted with buccal surface. For lingual, mesial and buccal implant surfaces of anterior implants, bone resorption at 12m was significantly higher than bone loss at 6m. Conclusion: Despite the limitation of this study, implants supporting mandibular overdentures with rigid telescopic attachments is a successful treatment option for edentulous mandible. However, this treatment modality is associated with increased bone loss around molar implants compared to canine implants. Also, the lingual implant surface was associated with significant higher bone resorption than other implant surfaces after one year of loading.

The sandwich osteotomy technique to treat vertical alveolar bone defects prior to implant placement: a systematic review.

The aim of this systematic review was to investigate the predictability of the sandwich osteotomy technique to provide sufficient alveolar bone height for dental implant therapy in vertically atrophic jaws. A MEDLINE (Pubmed), EMBASE and Cochrane Library electronic search and a manual search were performed until July 2018. Any clinical study published in English, reporting data on at least 10 patients rehabilitated with implant-supported dental prostheses after vertical ridge augmentation by means of the sandwich osteotomy technique and followed for at least 12 months after loading, was included. Data on study and patients' characteristics, interventions provided, implant and prostheses survival rates and complications were extracted from the included studies. Each study design was evaluated using the Cochrane Collaboration's tool for assessing risk of bias. Initially, 415 records were identified, from which 10 full-text articles could be included in the final qualitative analysis. Implant survival rate after a mean follow-up of 3.7 years (median: 3 years; range: 1-7 years) was 94% (median: 93%; range: 91-100%). Peri-implant mean marginal bone resorption was 1.6 mm (median: 1.4 mm; range: 0.6-4.7 mm). The calculated mean alveolar bone height available at the time of implant placement was 11.3 mm (median: 11.5 mm; range: 7.8-16 mm). A temporary sensory disturbance of the inferior alveolar nerve was the most commonly reported complication following the sandwich osteotomy. The present systematic review documents that implant survival rate after mandibular vertical ridge augmentation using the sandwich osteotomy technique is high after up to 5 years of loading. The complication rate can be considered moderate and has predominantly a transient nature. Data on the long-term behavior of the augmented bone and inserted implants are missing. The present technique can be considered a reliable treatment option in cases of moderate vertical bone deficiency of the posterior mandible to provide suitable conditions for later implant placement. Intra- and post-operative complications do not seem to jeopardize the final outcome.

Alveolar Crestal Approach for Maxillary Sinus Membrane Elevation with

Introduction For maxillary sinus membrane elevation (MSME), the lateral window approach and crestal approach are available, and high success rates have been achieved with low residual bone height as a development of technology. Objective To evaluate MSME using the crestal approach with a rotary-grind bur (RGB (including reamer or sinus bur)) in patients with residual bone height of <4 mm. Materials and Methods Ten implants were placed in 10 patients with residual bone height of <4 mm, by sinus elevation using an RGB. The implant stability quotient (ISQ) was measured immediately after implant placement (ISQ 1) and before taking impression for the final prosthesis (ISQ 2). The extent of marginal bone loss was measured on periapical radiographs. Results The mean residual bone height before implant placement was 3.41 ± 0.53 mm; no complications, including membrane perforation, severe postoperative pain, or discomfort, occurred either during or after surgery. The mean ISQ 1 was 63.4 ± 12.1, whereas the mean ISQ 2 was 77.6 ± 5.8. The mean marginal bone resorption was 0.23 ± 0.18 mm on periapical radiographs. Conclusions MSME using the crestal approach with an RGB is a reliable technique for implant placement in sites where available bone is insufficient.

Alveolar splitting with Piezosurgery®, bone bank grafts and NobelActive implants as an alternative to major bone grafting for maxillary reconstruction.

Piezosurgery® represents a novel alternative technique. The Piezosurgery® is well tolerated and permits a large number of applications in described literature. The principle of Piezosurgery® consists into inducing micro-vibrations to a metallic insert with a particular custom. The aim of this article is to study and to evaluate the use of NobelActive implants in combination with piezosurgical split-crest technique in severe atrophy of the upper maxilla. This approach allows avoiding the use of onlay grafts, due to rise the trasversal width of the crestal bone, which could have more complications and uncertain prognosis. This technique allows reducing timing of implant insertion because it is not necessary to wait for the graft to heal. Ten patients (age 45-58) are selected, presenting from class 4 to 5 by Cawood and Howell of jaws. Those underwent piezosurgical split-crest technique and simultaneous implants surgery and bone grafts. Preoperative X-ray evaluation included standard X-panoramic and CT Dental-scan. Standard chemoprophylaxis was administered to each patient. The piezosurgical split-crest procedure was combined with tissue bank fresh frozen chips and double-layer collagen membrane to improve the thickness of alveolar bone and simultaneous implant surgery. Every patient received simultaneously from 3 to 6 implants which diameter was 4.3 mm and length 10-11.5 mm. Healing abutments have been applied at 5 months from the first procedure. Patients were clinically monitored, and marginal bone changes were calculated using periapical radiographs, which were taken with O-ring technique at placement and upon subsequent appointments and a 1-mm measurement grid for marginal bone remodeling, again at baseline and thereafter 3 months within loading. Cumulative implant survival was 97.8% (N.=45). Mean marginal bone resorption (SD) was 1.19 (1.01) mm for the early loading group after 1 year. The use of NobelActive implants seem to reduce peak stress in both cortical and trabecular bone. The use of NobelActive implants was revealed ideal in patients presenting jaw atrophy. The tapered designs show an ability to dissipate the interfacial stresses of bone, therefore improving the stability and the osteointegration if used in association to split crest made with piezosurgical device.

Treatment Outcomes for Mandibular Mini-Implant-Retained Overdentures: A Systematic Review.

This systematic review evaluated treatment outcomes for mandibular mini-implant-retained overdentures (MMIOs) in terms of (1) implant survival rate, (2) peri-implant marginal bone loss, (3) prosthodontic maintenance and complication occurrence, and (4) patient satisfaction. Pertinent literature published in English before October 12, 2015 was identified using a MEDLINE and EMBASE search strategy and hand searching of relevant journals. Inclusion and exclusion criteria were applied to the titles and abstracts and subsequently to the full text of included studies. A total of 16 articles were included, from which qualitative and quantitative data were extracted for analysis. Of the 16 evaluated articles, 5 were randomized controlled trials, 8 were prospective studies, and 3 were retrospective studies. The follow-up time range from implant placement was 1 to 6 years, and only four studies included more than 3 years of follow-up. The mini-implant survival rate ranged from 86.9% to 100%. Mean marginal bone resorption was 0.28 to 1.2 mm after 1 year of loading. Of the 16 studies, 5 reported prosthodontic maintenance and complications, and all included studies showed significant improvement in patient satisfaction. Despite the limitations of this systematic review, particularly the short follow-up periods, the results suggest that MMIOs showed predictable results regarding implant survival rates, marginal bone resorption, and patient satisfaction.

Enhancement of Immediate Implant Stability and Recovery Using Platelet-Rich Fibrin.

The objective of this study was to evaluate the effect of leukocyte platelet-rich fibrin (L-PRF) on immediate implant stability and recovery. A total of 60 immediate implants were evaluated. After the extraction, using split-mouth design, test sockets were coated with L-PRF (L-PRF+) and control sockets were not (L-PRF-). All the implants were followed for 12 months. Results showed a statistically significant difference between the stability of L-PRF+ and L-PRF- implants at 1 week and at 1 month. Mean marginal bone resorption was higher in the control group at 1 year.

Maxillary overdentures supported by four or six implants in the anterior region: 5-year results from a randomized controlled trial.

ObjectiveTo compare a four‐ and six‐implant maxillary overdenture after an observation period of 5 years.Material and methodsFifty subjects with functional problems concerning their maxillary denture, who had ample bone volume in the anterior region to place four or six implants, were included and randomly assigned to either group. Implant and overdenture survival, clinical performance, marginal bone loss and patient satisfaction were assessed.ResultsForty‐six patients completed the 5‐year follow‐up. One implant failed in the six implants group (99.2% survival) and none in the four implants group (100% survival). No overdentures had to be replaced during the observation period and the number of complications was limited. Clinical function was good, with no difference in clinical parameters between the groups. Mean marginal bone resorption was 0.50 ± 0.37 and 0.52 ± 0.43 mm in the four and six implant group respectively.ConclusionIn patients with functional complaints of their maxillary denture, bar‐supported overdentures on four implants in the anterior maxillary region were not inferior to overdentures supported by six implants after 5 years of function. Implant survival and patient satisfaction were high, clinical parameters favourable, bone loss and complications to the denture were minor in both groups (Clinical trial registration number: NTR2969).

Graftless Full-Arch Implant Rehabilitation with Interantral Implants and Immediate or Delayed Loading-Part II: Transition from the Failing Maxillary Dentition.

To compare long-term survival and marginal bone loss of immediate interantral implants in the nonaugmented maxilla subjected to immediate vs delayed loading. Graftless maxillary cross-arch rehabilitation was performed in a total of 362 patients in the years 2004 to 2013 (1,797 implants). Of the 240 patients with immediate implants replacing their failing maxillary dentition, 81% were subjected to immediate loading and 19% to delayed loading of their 4 to 6 interantral implants (980 and 235 implants, respectively). Kaplan-Meier survival estimates were computed and marginal bone loss was evaluated in a stratified random sample of 20 patients per group. Thirty-one of 1,215 implants failed within the mean observation period of 3.9 years, and no difference in 8-year survival estimates could be seen between immediate (97.6% [95% CI: 96.7 to 98.6]) and delayed (96.6% [95% CI: 94.3 to 98.9]) loading protocols (P = .359). Mean marginal bone resorption following implant insertion did not differ significantly between the groups (1.5 ± 1.7 mm vs 0.7 ± 1.1 mm, P = .379); however, it was significantly associated with a reduced number of implants (P = .017) and patient history of periodontal disease (P < .001). Immediate loading of interantral implants yields satisfactory results in the transition of patients from a failing maxillary dentition to full-arch implant rehabilitation and thus may be favored over delayed loading concepts.

Graftless Full-Arch Implant Rehabilitation with Interantral Implants and Immediate or Delayed Loading-Part I: Reconstruction of the Edentulous Maxilla.

To compare long-term survival and marginal bone loss of late interantral implants in the nonaugmented edentulous maxilla subjected to immediate vs delayed loading. One hundred twenty-two edentulous patients with implants in native, healed jawbone were subjected to either immediate loading (179 implants) or delayed loading (403 implants) of their four to six interantral implants (part I of 362 graftless maxillary cross-arch rehabilitations performed in the years 2004 to 2013). Kaplan-Meier survival estimates were computed, and marginal bone loss was evaluated in a stratified random sample of 20 patients per group. Fifteen of 582 implants failed within the mean observation period of 4.7 years, and no difference in 8-year survival estimates could be seen between immediate (98.3% [95% CI: 96.4-100.0]) and delayed (96.7% [95% CI: 94.7-98.6]) loading protocols (P = .370). Mean marginal bone resorption following implant insertion did not differ significantly between the groups (1.1 ± 1.3 mm vs 1.4 ± 1.3 mm, P = .490). Immediate loading of interantral implants in the nonaugmented edentulous maxilla yields favorable results comparable to delayed loading and may be considered to shorten periods of removable provisional prostheses in maxillary edentulism.

Marginal Bone Level Evaluation after Functional Loading Around Two Different Dental Implant Designs.

Purpose. To investigate peri-implant alveolar bone changes using periapical radiographs before and after prosthetic delivery in submerged and nonsubmerged dental implants. Methods. Digital periapical films of 60 ITI Straumann nonsubmerged dental implants and 60 Xive Dentsply submerged dental implants were taken before, immediately after, and 12 and 24 weeks after the prosthetic restoration was delivered. Results. The 60-nonsubmerged dental implant group showed mean marginal bone resorption at baseline of 0.10 ± 0.23 mm and 24 weeks later, marginal bone resorption was 0.16 ± 0.25 mm. The submerged dental implant group showed a significantly higher distal marginal bone resorption over the mesial side. Mean marginal bone resorption at baseline was 0.16 ± 0.32 on the mesial and 0.41 ± 0.56 on the distal side. Twenty-four weeks later, it was 0.69 ± 0.69 mm on the mesial and 0.99 ± 0.90 mm on the distal side. Conclusion. First, it was possible to determine that submerged implants had a higher mean marginal bone resorption and less bone-to-implant contact than nonsubmerged implants. And second, the distal side of submerged dental implants presented higher marginal bone loss than the mesial side.

Long-term follow-up of implants with reduced length

Introduction: The aim of this study was to assess the reduced length implants as an alternative of conventional length implants in combination with bone augmentation. The following criteria were observed: survival rate, marginal bone loss, bleeding on probing. Material and Methods: This study included 186 Straumann Standard Plus implants with dimensions: length of 6 mm and diameter of 4.8 mm. The implants were loaded with non-removable crowns or bridges at least 10 weeks after the implant placement. Depending on the type of the prosthetic option the distribution of the implants was as follows: 83 implants were co-abutments to one more implant with conventional length (8-14 mm); 67 implants were co-abutments to more than one implant with conventional length, 33 implants were loaded with single crowns. Results: The mean period of observation was 5.59 years. The mean marginal bone resorption was 0,224mm. In 12.4% from the cases was registered BOP (bleeding on probing). A correlation was found between the BOP and mean marginal bone resorption. No correlation was found between the values of marginal bone resorption and the type of the prosthetics. The survival rate of the implants in the observation period was 99.5%. Conclusion: Тreatment by short implants is a reliable alternative to implants with conventional length with combination of bone grafting procedures. It is less invasive, cost effective and consumes less treatment time.

Five-year follow-up of implants placed simultaneously with inferior alveolar nerve lateralisation or transposition

Introduction: The aim of this investigation was to evaluate the 5-year outcomes regarding presence of intraoperative and postoperative complications and the survival rate of implants placed simultaneously with lower alveolar nerve lateralization or transposition. Material and Methods: implants placement was performed on 34 patients with advanced atrophy of the posterior mandible simultaneously with lower alveolar nerve lateralization or transposition. Transposition was done only in two cases; in the rest of the cases lateralization of lower alveolar nerve was performed. Results: The survival rate at the end of the fifth year after implant placement was 100%. The mean height of residual bone at the region of implant placement was 2.76 mm. The mean marginal bone resorption for at the fifth year was 0.309 mm. In 20.6% of cases a positive BOP (bleeding on probing) was registered. 14.7% of the patients were free of symptoms of NSD (neuro-sensory dysfunction). In the rest of the patients the mean duration of NSD was 2.06 weeks. In 76.4% of patients the symptoms of NSD of nervus alveolaris inf. resolved after the second week. The maximum period of reported NSD was 6 weeks. No permanent NSD occured. Conclusion: Properly performed lateralization or transposition of the lower alveolar nerve is associated with minimal risk of permanent neuro-sensory dysfunction and providing an opportunity for placement of intraosseal implants in the posterior mandible with high survival rate.

Four implant bar-connected implants sufficient to support a maxillary overdenture

Randomised controlled trial. Edentulous patients aged at least 18 years with lack of retention and stability of the upper denture and lower denture were randomised to receive a maxillary overdenture supported by either four or six bar-connected implants. The primary outcome measure was change of radiographic bone level. Secondary outcome measures were implant survival, overdenture survival and soft tissue conditions (plaque index, presence of calculus, gingiva index, sulcus bleeding index and pocket probing depth). These were scored at placement of the overdenture and after 12 months of loading. Patient satisfaction was also scored at baseline and at 12 months. Forty-nine patients (one drop out) completed the one year follow-up. Mean marginal bone resorption was 0.24 ± 0.32 mm in the four implants group and 0.25 ± 0.29 mm in the six implants group. Implant survival was 100% in the four implants group and 99.3% in the six implants group (one implant lost). Overdenture survival was 100% in both groups. There were no differences in the soft tissue outcomes between the groups. Patient satisfaction had improved in both groups. After one year a bar-connected maxillary overdenture on four or six implants results in a comparable treatment outcome with high implant survival, healthy peri-implant tissues and high patient satisfaction. For reasons of cost-effectiveness, treatment with four bar-connected implants to support a maxillary overdenture is preferred.