Bone Level Changes Research Articles

Is Bone Grafting during Implant Placement a Protective Factor against the Development of Peri-implantitis? A Retrospective Cohort Analysis

This study aims to identify if the use of bone grafting at time of implant placement is a protective factor against the development of peri-implantitis. A retrospective cohort study was conducted at the Philadelphia Veterans Affairs Medical Center from 2006 to 2013. Physician encounter notes within three months of implant placement were used to gather data about patients' health status. Operative report notes were used to assess the use of bone grafting at time of implant placement. Implant status was assessed using dental encounter notes and radiographs from follow-up appointments at one, three, five and 10 years. Peri-implantitis was defined as radiographic evidence of changes in the crestal bone level, clinical evidence of bleeding on probing with or without suppuration. Electronic medical records of 797 implants were retrospectively analyzed. Statistics were computed using the SAS System (SAS Institute Version 9.4, 2002-12, Cary, NC). The primary predictor variable was bone grafting at time of implant placement (xenograft, allograft or autograft). The primary outcome variable was the presence of peri-implantitis. Other study variables assessed were diabetes, smoking, gender and age. Descriptive, univariate and multivariate regression analyses were performed to measure the association between predictive variables and development of peri-implantitis. Of the 797 implants placed, 168 (21%) developed peri-implantitis. Following a multivariate analysis that controlled for diabetes, smoking, gender and age, placement of bone graft at implant placement was shown to be associated with a decreased risk in the presence of peri-implantitis (p = 0.050) when compared to implants that did not receive bone graft. The data from this study show that implants placed with simultaneous bone graft were 44.7 percent less likely to develop peri-implantitis compared to implants placed without bone graft (OR = 0.553, 95 percent Cl 0.303-1.000). To the researchers' knowledge, no existing literature demonstrates this significant, protective relationship. Human studies demonstrate a significant contraction of ridge dimensions following extraction, even when immediately restoring with an implant. However, the placement of bone graft during implant placement was shown to histologically modify the process of bone healing and provide additional hard tissue at the extraction socket when compared to sockets restored with no graft. Therefore, in conjunction with the results, the use of bone graft at the time of implant placement may reinforce the surrounding implant site on a biochemical or structural level and provide protective features against the development of peri-implantitis. Analysis of implants placed at the Philadelphia VA Medical Center revealed an important association between use of bone grafting at implant placement and the development of peri-implantitis. The study shows that the supplemental placement of bone graft may play a role in decreasing the development of peri-implantitis. However, it is important to note that the use of bone grafting is case-specific for areas that may be deficient of peri-implant tissue. As the restoration of edentulous areas with dental implants is becoming the new standard of care, identifying protective factors, such as use of bone grafting during implant placement, will be critical in ensuring successful outcomes. In addition to completing prospective studies, identification of other implant protective and risk factors is a necessity. 1. Lang, NP, et. al: Periimplant diseases: where are we now? consensus of the Seventh European Workshop on Periodontology. J Clin Periodontol, 2011. 2. Alves D, Faria-Almeida R, Azevedo A, Liñares A, Muñoz F, Blanco-Carrion J: Immediate 1-piece zirconia implants with/without xenograft in the buccal gap: a 6-month pre-clinical study. Clin Oral Implants Res, 2021

Is Immunosuppression a Risk Factor for Development of Peri-implantitis? A Retrospective Cohort Analysis

The present study aims to identify if immunosuppression is a risk factor for the development of peri-implantitis. A retrospective cohort study design was conducted on patients presenting to the Philadelphia Veterans Affairs (VA) Medical Center for dental implant placement from 2006 to 2013. Medical encounter notes within 3 months of implant placement were used to collect information about patients’ health status, including evaluations of immune system function. Implant status was assessed using dental encounter notes and radiographs from follow-up appointments at 1, 3, 5, and 10 years. Peri-implantitis was defined as radiographic evidence of change in crestal bone level, clinical evidence of bleeding on probing, with or without suppuration.1Electronic medical records of 884 implants were retrospectively analyzed. Descriptive statistics were calculated using the SAS System (SAS Institute Version 9.4, 2002-2012, Cary, NC). The primary predictor variable was immunosuppression. The primary outcome variable was the presence of peri-implantitis. Other study variables assessed included graft at the time of implant placement, diabetes, smoking, gender, and age over 60. Descriptive, univariate, and multivariate regression analyses were performed to measure the association between predictive variables and development of peri-implantitis.Of the 884 implants placed, 205 (23.1%) developed peri-implantitis. Following a multivariate analysis that controlled for diabetes, smoking, gender, and age over 60, immunosuppression was shown to be significantly associated with an increased risk in the presence of peri-implantitis (P = .0071) when compared to implants placed in immunocompetent subjects. The data from this study show that implants placed in immunosuppressed patients were 29.78% more likely to develop peri-implantitis compared to implants placed in immunocompetent patients (OR = 2.229, 95% CI 1.243-3.996). To the best of the authors’ knowledge, no existing literature has demonstrated this significant risk relationship.Following surgical implant placement, adequate function of the immune system's inflammatory response is imperative to target infections and orchestrates wound healing to allow for successful osseointegration of implants. Few studies, however, have directly investigated this nexus at a mechanistic level. In vivo studies in rabbits have indicated that titanium implant placement may up-regulate the immune system's type 2 inflammatory response to inhibit bone resorption markers and promote healing.2 Therefore, in conjunction with the authors' results, immunosuppression could play a significant role in increasing risk of peri-implantitis.Analysis of implants placed at the Philadelphia VA Medical Center revealed an important association between immunosuppression and the development of peri-implantitis. This study shows that immunosuppression may play a role in increasing the development of peri-implantitis. Along with need for further exploration regarding the pathophysiology of this relationship, additional observational and randomized controlled studies are necessary to validate the authors' findings. As implant restoration of edentulous areas is becoming the new standard of care, identification and understanding of associated risks factors are critical to ensure successful implant outcomes.

Alveolar bone changes after molar protraction in young adults with missing mandibular second premolars or first molars.

To assess the changes in alveolar bone of the mandibular second molars following molar protraction and investigate the factors associated with the alveolar bone changes. Cone-beam computed tomography of 29 patients (mean age 22.0 ± 4.2 years) who had missing mandibular premolars or first molars and underwent molar protraction were reviewed. Alveolar bone level was measured as the distance from the cementoenamel junction at six points, buccal, lingual, mesiobuccal (MB), mesiolingual (ML), distobuccal (DB), and distolingual (DL), of the second molars at pretreatment (T0) and after molar protraction (T1). Factors associated with alveolar bone changes at the distal and mesial of the second molars were assessed. Mean alveolar bone changes ranged from -1.2 mm (bone apposition) to 0.8 mm (bone resorption). The presence of a third molar impaction at T0 (P < .001), third molar angulation at T0 (P < .001), and Nolla's stage of third molar at T0 (P = .005) were significantly associated with alveolar bone level changes distal to the second molars. Treatment duration (P = .028) was significantly associated with alveolar bone level changes mesial to the second molar. Patients with impacted third molars, third molars at an earlier stage of development, and mesially angulated third molars at pretreatment may have less alveolar bone resorption distal to the second molars following protraction. Patients with increased treatment time may have reduced alveolar bone resorption mesial to the second molars.

Peri-implant bone-level changes in the second decade of loading with regard to the implant\u2013abutment connection: a retrospective study on implants under systematic aftercare

BackgroundThis retrospective study investigates the change in the peri-implant bone level (PBL) during the 2nd decade of intraoral function in patients complying with a ‘supportive implant therapy’ (SIT) program. The results were statistically analyzed with respect to the implant abutment connection used.MethodsIn a private practice, only patients with 20-year SIT compliance were identified. Of these, all patients with 10- and 20-year radiographs available were selected. Therefore, no control group was possible and implant losses had to be excluded. Two experienced researchers assessed the peri-implant bone levels. As three different abutment connection concepts (bone-level butt-joint, bone-level conical and tissue-level conical) and two different implant surfaces (machined vs. roughened) were involved, statistical analyses were performed to detect potential differences.ResultsNinety-three implants from 36 patients with 20-year SIT compliance and available radiographs were included in the study. At study baseline (10 years intraoral), a mean bone loss of − 1.7 mm (median − 1.2; standard deviation [sd] 1.4, range: 0 to − 7.2) was recorded. After 20 years, we found a mean bone loss of − 2.5 mm (median − 2.3, sd 1.79, range: − 0.5 to + 7.4). Furthermore, we found a mean bone loss of 0.8 mm in intraoral function from year 10 to year 20 (mean: 0.08 mm per year); this change was independent of the abutment connection type.ConclusionsDuring the 2nd decade of function, peri-implant bone loss in patients with SIT compliance might be small in value and should not be expected in all implants.

Severely Atrophic Mandibles Restored With Fiber-Reinforced Composite Prostheses Supported by 5.0-mm Ultra-Short Implants Present High Survival Rates Up To Eight Years

Encouraging results have been reported for ultrashort single implants; however, long-term investigations are warranted for full-arch reconstructions. This study evaluated marginal bone loss, implant, and reconstruction survival of fiber-reinforced composite full-arch prostheses supported by 4 ultrashort implants. Patients with severely atrophic mandibles (Cawood and Howell class V and class VI) were included in this cohort study. Study predictors included time (initial and last follow-up) and vertical (epicrestally or subcrestally) and horizontal implant position (medial or lateral). Outcome variables included bone level changes over time, implant/prosthesis survival. Peri-implant bone level was measured on panoramic radiographs. Descriptive statistics, Kaplan-Meier, mixed model analysis of variance, and univariate and multivariate Cox Proportional Hazards Regression models, adjusted for multiple implants in the same patient, were used for data analyses. Eighteen patients (mean 61.22 years old), with 72 implants placed in atrophic mandibles with an average follow-up of 55.4 months (CI, ±4.6/ SD, ±10.6 months) were analyzed. The implant survival rate was 97.2% as 2 implants were not loaded due to non-osseointegration and sensorial disturbances. Average marginal bone level at baseline (1.93 mm) and at the time of last recall (1.91 mm) was not significantly different. While implants placed subcrestally showed no significant difference between baseline (1.91 mm) and last follow up bone level (2.12 mm), implants placed epicrestally demonstrated a significant reduction on their bone level over time (initial: 1.97 mm/ final:1.33 mm). Systemic disorders were a risk factor for implant survival and bone loss. Prostheses cumulative survival rate was 100% (mean observation period of 55 months). The estimated survival rate after the 96-month follow-up was 75% (1 framework fracture after 84 months). Fixed fiber-reinforced composite full-arch prostheses retained by 4 ultrashort implants showed a stable bone level and high implant/prostheses survival rates up to 8 years.

Two short implants versus one short implant with a cantilever: 5-Year results of a randomized clinical trial.

AimTo test whether or not the use of a short implant with a cantilever results in similar clinical and radiographic outcomes compared to two adjacent short implants with single tooth reconstructions.Materials and methodsThirty‐six patients with two adjacent missing teeth in the posterior region were randomly assigned to receive either a single 6‐mm implant with a cantilever (ONE‐C) or two 6‐mm implants (TWO). Fixed reconstructions were inserted 3–6 months after implant placement and patients were re‐examined up to 5 years (FU‐5).ResultsA total of 26 patients were available for re‐examination at FU‐5. The survival rate amounted to 84.2% in ONE‐C and to 80.4% in TWO (inter‐group: p = .894). Technical complication rates amounted to 64.2% (ONE‐C) and to 54.4% (TWO) (inter‐group: p = 1.000). From baseline to FU‐5, the median changes of the marginal bone levels were 0.13 mm in ONE‐C and 0.05 mm in TWO (inter‐group: p = .775). Probing depth, bleeding on probing, and plaque control record values showed no significant differences between the two treatment modalities (p > .05).ConclusionsShort implants with a cantilever render similar clinical and radiographic outcomes compared to two adjacent short implants at 5 years, however, they tend to fail at earlier time points suggesting an overload of the implants. Considering the modest survival rates, the clinical indication of either treatment option needs to be carefully evaluated. ClinicalTrials.gov (NCT01649531).

Do postoperative antibiotics influence one-year peri-implant crestal bone remodelling and morbidity? A double-blinded randomized clinical trial.

ObjectivesThe primary objective of this study was to assess whether giving postoperative antibiotics to healthy patients after straightforward platform‐switched implant placement would influence peri‐implant crestal bone levels and postoperative morbidity after 1 year.MethodsThirty‐eight healthy individuals were recruited in this pilot, randomized, double‐blinded, placebo‐controlled clinical trial. The intervention group (n = 18) received two grams of amoxicillin one hour before implant placement followed by a 7 days postoperative regimen (500 mg tid). The control group (n = 20) took the same preoperative dose of amoxicillin and an identical placebo postoperatively. Mesial and distal peri‐implant crestal bone levels were measured at baseline, four months and one year later with standardized periapical radiographs. Postoperative pain severity was assessed through self‐administered questionnaires for 7 days. Surgery‐associated morbidities were evaluated after one, three, 16 weeks and 1 year. Descriptive and bivariate analyses were used.ResultsThirty‐seven participants completed the trial. At the one‐year follow‐up, the mean combined peri‐implant crestal bone changes for the intervention (n = 18) and control (n = 19) groups were ‐ 0.44 ± 0.41 mm and ‐ 0.27 ± 0.56 mm, respectively. The difference between the groups (intervention–control) for mean combined crestal bone level changes was not statistically significant. There were no significant differences in surgery‐associated morbidities between the intervention and control groups. The one‐year implant survival rate was 100% in both groups.ConclusionsStudy results suggest that a routine postoperative antibiotic regimen for healthy patients undergoing straightforward platform‐switched implant placement might not be necessary to prevent postoperative peri‐implant bone loss and complications.

A Retrospective Study of Bone-Level Stability Around 335 Hybrid Implants Placed with an Immediate or Delayed Protocol.

This retrospective study evaluated 335 hybrid implants placed in edentulous ridges; 167 were placed with an immediate implant protocol (IIP) and 168 were placed with a delayed implant protocol. Radiographic bone level changes were measured 1 to 23 years after loading. The average bone loss between implant placement and second-stage loading was 0.16 mm in the delayed group and 0.12 mm in the IIP group. Average bone loss from implant loading to the final radiograph was 0.26 mm in the IIP group and 0.13 mm in the delayed group. There was statistically significantly more bone loss in the IIP group, in patients taking amoxicillin (vs those taking azithromycin), in sites with splinted implants (vs nonsplinted implants), and in smokers (vs nonsmokers). However, even when statistically significant, bone loss would be considered clinically insignificant by most clinicians over the 1- to 23-year follow-up.

3-D tooth movement adjacent to single anterior implants and esthetic outcome. A 14- to 20-year follow-up study.

To report three-dimensional (3-D) movement of teeth adjacent to single-implant crowns (SICs) in the anterior maxilla and to relate the findings to patient characteristics and esthetic outcome. 3-D movements of teeth adjacent to anterior maxillary SICs were measured in 30 patients with original SICs in function after 14-20years. The movements were related to facial type, lower anterior facial height (LAFH), age at crown delivery, sex, the position of the implant, implant occlusion, cause of tooth loss, follow-up period, orthodontic treatment prior to implant placement, and marginal bone-level changes. The esthetic outcome and quality were assessed using Visual Analog scale (VAS) and California Dental Association (CDA) index. 3-D movement of adjacent teeth between 0 and 2.5mm was observed at follow-up with incisal and palatal movement being most pronounced. Incisal tooth movement of >1mm was observed in 30% of the patients and was significantly associated with LAFH ≥70mm. VAS rating associated poorly between patients and clinicians with scores of >80% in 63% and 20%, respectively. The CDA rating was assessed as satisfactory in 87% of the patients. Significantly more extensive infraposition was observed in patients with SICs without occlusion, other causes of tooth loss than trauma, implant in lateral incisor and canine position, and a LAFH of ≥70mm. Although infraposition occurs, patients are highly satisfied with the esthetics of their implants and the esthetic results are valued as higher by patients than dentists.

Evaluation of immediately loaded mandibular four vertical versus tilted posterior implants supporting fixed detachable restorations without versus with posterior cantilevers.

Distally inclining posterior implants may be technically challenging in certain situations. The presence of a posterior cantilever can also exert unfavorable forces on supporting implants. The aim of the present study was to evaluate and compare peri-implant soft and hard tissues around 4 mandibular interforaminal implants having tilted posterior implants with posterior cantilevers, versus vertical implants, 2 in the interforaminal region and 2 in the first molar regions, without posterior cantilevers. All implants supported full-arch fixed detachable restorations opposing complete dentures. A total of 80 implants were placed flapless in the mandibles of 20 edentulous participants. Four implants were placed for every participant, who were randomly assigned into 2 equal groups. Axial group implants were vertically aligned, with 2 implants in the interforaminal area and 2 in the molar area. Tilted group implants have 2 anterior axial and 2 posterior distally inclined implants. Interim screw-retained prostheses converted from pre-existing dentures were immediately fabricated and loaded on the same day of surgery. After awaiting period of 3months, all participants received fixed detachable metal acrylic resin definitive restorations. A follow-up protocol of 3, 6, and 12months was scheduled to assess the modified gingival index, modified plaque index, peri-implant probing depth, implant stability, and marginal bone level and bone density changes. No statistically significant differences (P > .05) were found in the modified gingival index, modified plaque index, peri-implant probing depth, implant stability, bone density, and marginal bone level between the axial and tilted implant groups after the 1-year follow-up period. Placing 4 flapless immediately loaded implants in mandibular edentulous patients that supported full-arch fixed restorations provided high implant and prosthodontic success rates whether posterior implants were tilted with posterior cantilevers or vertically aligned without posterior cantilevers. Pan African Clinical Trial Registry database, PACTR201907776166846. Registered 3 July 2019, www.pactr.org .

The effect of implant-abutment connections on peri-implant bone levels around single implants in the aesthetic zone: A systematic review and a meta-analysis.

ObjectiveTo systematically review literature about the effect of different implant‐abutment interface designs on peri‐implant bone level changes, implant loss and mid‐buccal mucosa changes around single implants in the anterior maxilla. Reviewing three connection configurations: Platform switched conical (PS‐conical); Platform switched parallel (PS‐parallel); Platform matched parallel (PM‐parallel).MethodsA detailed search was carried out in Pubmed, EMBASE, Cochrane, Scopus, Open Gray and African journals Online (until December 1, 2020) and was restricted to clinical prospective studies of at least 1 year and with at least 10 human participants. A meta regression analysis was carried out primarily on the pooled peri‐implant bone level changes followed by implant loss and mid‐buccal mucosa level change. Risk of bias was assessed with RoB 2.0 and ROBINS‐I. The manuscript complied with the PRISMA guidelines and was registered in the PROSPERO database (ID: 225092).ResultsA total of 5513 hits gave 44 eligible articles for the analyses. Bone level change did not differ significantly between the two platform switched connections; their bone loss scores were significantly lower than PM‐connection. The PS‐conical connections have significantly lower implant losses than the PM connection. Mid‐buccal mucosa level change was comparable between the three connection configurations. Moderate to high risk of bias was detected in the included studies.ConclusionsThe performance of PS‐conical and PS‐parallel connection configurations both favored bone loss scores compared to the PM‐parallel connection configuration. All three demonstrated mid‐buccal mucosa changes that were small and did not differ significantly amongst the groups.

Peri-implant and esthetic outcomes of cemented and screw-retained crowns using zirconia abutments in single implant-supported restorations-A systematic review and meta-analysis.

To evaluate the peri-implant tissue changes and esthetic outcomes of cemented and screw-retained crowns of single-tooth implants in the esthetic zone using zirconia abutments. An electronic search was performed on nine databases. The risk-of-bias was assessed by the revised Cochrane risk-of-bias tool for randomized (RoB 2) and non-randomized (ROBINS-I) clinical trials. Marginal bone level change, soft tissue thickness, bleeding on probing, probing depth, survival rates of implants and crowns, complications, plaque and papilla indexes, and pink esthetic score data were extracted and analyzed. The certainty of evidence was accessed through the GRADE approach. Nine records were included and 7 were used in the meta-analyses. Screw-retained crowns presented greater marginal bone level change (MD -0.04 [-0.08, -0.00] p=0.04, I2 =0%) compared to cemented crowns up to 1-year. At 3 and 4years no significant differences (p>0.05) were observed. Soft tissue thickness did not differ between groups (p>0.05). The bleeding on probing was higher in cemented group than in screw-retained crowns at 1-year (MD 0.17 [0.08, 0.27] p=0.0005, I2 =0%), at medium-term periods (3 and 4years) no statistically significant differences (p>0.05) were observed for this outcome. Probing depth, survival rates of implants and crowns, complications, and plaque index, as well as esthetic analysis using the papilla index and pink esthetic score did not differ statistically (p>0.05) between both retention systems at short and medium-term periods. The connection system considering zirconia abutments presented no influence on peri-implant parameters and esthetics evaluation for medium-term periods (3 and 4years).

Bone‐level changes around implants with 1‐ or 3‐mm‐high abutments and their relation to crestal mucosal thickness: A 1‐year randomized clinical trial

To evaluate 1-year bone-level changes around subcrestal platform-switching implants with 1 or 3 mm definitive abutments. The influence of mucosal thickness on bone-level alterations was further analysed. Implants were placed in the posterior sextants and positioned 1.5 mm subcrestally with an abutment of 1 or 3 mm height. Final restorations were delivered after 16 weeks. Radiographic measurements of inter-proximal bone level were the primary outcome and were adjusted by vertical mucosal thickness. Peri-implant clinical conditions and resonance frequency analysis were also compared. A total of 65 subjects with 99 implants were analysed. The overall 1-year implant survival rate between the 1- and 3-mm groups was 96.4% and 94.4%, respectively. Statistically significant lower inter-proximal marginal bone-level changes were observed in the 3-mm group (1 mm: -0.17 ± 0.02 mm at mesial and -0.21 ± 0.02 mm distal; 3 mm: -0.03 ± 0.02 mm at mesial and -0.03 ± 0.02 mm and distal; mesial: p=.001; distal: p < .001). Initial vertical mucosal thickness was not correlated with inter-proximal marginal bone loss. Subcrestal implants with 3-mm abutment were associated with minimal inter-proximal bone loss. Independent of the abutment height, crestal mucosal thickness was not correlated with bone loss.

One-Abutment One-Time Effect on Peri-Implant Marginal Bone: A Prospective, Controlled, Randomized, Double-Blind Study.

Objective: To evaluate the peri-implant hard tissue change at 6 and 12 months after implant placement between definitive abutment placed at the same time of implant surgery, never removing it, and healing abutment disconnected and reconnected three times until the placement of the final rehabilitation. Material and methods: Each partial edentulous patient could receive between 1 and 4 platform-switched implants in the posterior regions. If the implants had primary stability—implant stability quotient (ISQ) equal to or greater than 50, they were randomized to the test group with the abutment inserted at the same time of implant placement (DA) or to the control group, receiving a healing abutment (PA). At 6 and 12 months after surgery, data related with vertical bone level changes (primary outcome) and other clinical parameters (implant mobility, bleeding on probing, probing depth, plaque index) were assessed. Results: 53 implants were included in the trial and completed 12 months follow-up (overall survival rate: 100%). All implants achieved primary stability, with an average ISQ value of 80.9 on the day of surgery. From surgery to 6 months, the mean bone loss was 0.14 ± 0.18 mm for the DA group and 0.23 ± 0.29 mm for the PA group, without statistical significance difference. Between 6 and 12 months, the mean bone loss was 0.14 ± 0.21 mm for the DA group and 0.21 ± 0.27 mm for the PA group, also without statistical significance between the two groups. There were no statistically significant differences (p = 0.330) in total bone loss after 12 months between the control and the study groups. Conclusions: The one abutment one time protocol has at least an equivalent effect on the peri-implant bone level changes when compared with the use of healing abutments that are disconnected and reconnected at least three times.

Tomographic Assessment of reinforcement of acrylic resin denture base for palateless implant locator retained maxillary over denture.

Objectives: This study was conducted to evaluate the effect of metallic (cobalt chromium), glass fiber and nano zirconia oxide reinforcement of acrylic resin denture base on the peri-implant crestal bone level changes in palateless locator retained maxillary over denture. Materials and Methods: Twenty-one completely edentulous male patients with maladaptive experience to maxillary dentures were selected to participate in this study. For all patients maxillary four implant-retained overdenture was constructed following the same basic principles. Every patient received four implants, two in the canine region with (3.6 mm in diameter & 12mm in length), and two in the second premolar region with ( 4.5 mm in diameter & 8mm in length); (Tiologic® Implants, Dentaurum, Ispringen, Germany) . Metal (cobalt chromium) reinforced over denture was constructed for the first group , while 5% fiber reinforced acrylic resin denture was constructed for the second group and Overdenture was reinforced using 5% of nano ZrO2 for the group three patients. . Follow up visits were scheduled twelve and twenty four after implant loading for inspection of the prosthesis and radiographic evaluation Peri-implant crestal bone level changes were assessed using intra-oral radiographs taken . Results: The findings of the present study demonstrates that all the studied denture base reinforcement materials individually showed significance bone loss around implants (p < 0.05) after 12 months follow up period. Conclusion: Within the limitations of this study, reinforcement of polymethyl methacrylate denture base with glass fiber or nano zirconia oxide should be considered in palateless implant retained maxillary over denture.

Clinical and radiographic performance of self-locking conical connection implants in the posterior mandible: Five-year results of a two-centre prospective study.

ObjectiveThis prospective study aims to assess the 5‐year clinical performance of implants with internal conical connection and platform‐switched abutments in the posterior mandible.Material and MethodsHealthy adults missing at least two teeth in the posterior mandible and with a natural tooth mesial to the implant site received two or three adjacent implants. After a transmucosal healing period single crown restorations were cemented on platform‐switched abutments. Changes in marginal bone levels were investigated in standardized periapical radiographs from surgery and loading (baseline) to 60‐months post‐loading.ResultsTwenty‐four patients received 52 implants. Bone remodelling took place between surgery and loading (mean:‐0.5, SD:±0.4 mm). From loading to 60 months, there was a mean bone change of 0.27 (SD:±0.47 mm) which stabilized 24 months after prosthesis delivery (mean:0.2, SD:±0.46 mm). 71.7% of all implants presented bone preservation at 60 months irrespective of the initial insertion depth. Two implants were lost after 5 years and the success rate was 95.1%. Patient enquiry revealed high satisfaction.ConclusionInternal conical connection implants with platform‐switched abutments presented a high success rate and preservation of marginal bone levels at the implant shoulder after 5 years of loading.

A Novel Parallel-Walled Dental Implant with a Self-Tapping Apex, Conical Connection, and Platform Shifting: Short-Term Results from a Retrospective Multicenter Clinical Study.

This multicenter retrospective study assessed clinical and radiographic outcomes of 686 parallel-walled conical-connection implants consecutively placed in 281 partially and fully edentulous patients. Implants were placed in healed and postextraction sites and subjected to immediate, early, or delayed loading. With a mean follow-up of 10 ± 6.7 months, the implant survival rate was 97.7%, while mean marginal bone loss was 0.7 ± 1.5 mm between implant placement and 1 year (n = 290 implants) and 0.1 ± 0.6 mm between 1 and 2 years (n = 72 implants). Advanced patient age and longer implants were associated with fewer implant failures, while different crestal positions at implant placement were not associated with differences in implant survival or changes in marginal bone level over time.

Bone loss-related factors in tissue and bone level dental implants: a systematic review of clinical trials.

Dental implants are popular for dental rehabilitation after tooth loss. The goal of this systematic review was to assess bone changes around bone-level and tissue-level implants and the possible causes. Electronic searches of PubMed, Google Scholar, Scopus, and Web of Science, and a hand search limited to English language clinical trials were performed according to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analysis) guidelines up to September 2020. Studies that stated the type of implants used, and that reported bone-level changes after insertion met the inclusion criteria. The risk of bias was also evaluated. A total of 38 studies were included. Eighteen studies only used bone-level implants, 10 utilized tissue-level designs and 10 observed bone-level changes in both types of implants. Based on bias assessments, evaluating the risk of bias was not applicable in most studies. There are vast differences in methodologies, follow-ups, and multifactorial characteristics of bone loss around implants, which makes direct comparison impossible. Therefore, further well-structured studies are needed.

Long-term survival and success of zirconia screw-retained implant-supported prostheses for up to 12 years: A retrospective multicenter study

Statement of problemDespite the broad clinical application of zirconia for fixed implant-supported prostheses, evidence of long-term performance is sparse. PurposeThe purpose of this retrospective study was to evaluate the long-term clinical and radiographic outcomes of zirconia-based partial and complete screw-retained implant-supported zirconia fixed dental prostheses (ISZFDPs). Material and methodsRecords of patients treated with dental implants and ISZFDPs between December 2004 and June 2017 were screened. Eligible study participants, according to inclusion criteria, were contacted and invited to undergo clinical and radiographic examinations. Outcomes were evaluated as implant and prosthetic survival rates, prosthetic success rate, complications, marginal bone level (MBL) change, and soft tissue condition. Along with the effects of zirconia prosthesis type and level, the effects of implant type and connection, type of loading, and follow-up on MBL were tested with a generalized linear effects model (GLEM) (α=.05). ResultsA total of 118 patients were identified, of whom 20 (16.9%) were not available for clinical examination for various reasons. Ninety-eight participants (mean age 60.7 ±11.7 years) with 337 implants were included, of which 176 (52.2%) had been immediately loaded. A total of 111 ISZFDPs (96 zirconia connection and 15 titanium base) were investigated: 24 complete ISZFDPs with a zirconia connection (12.9 ±0.97 dental units, minimum 12, maximum 14), 72 partial with a zirconia connection (3.11 ±1.12, minimum 2, maximum 7), 15 partial with a titanium base (3.62 ±1.02, minimum 2, maximum 5). Forty ISZFDPs had been in function for ≥10 years (36%), 38 for 5 to 9 years (34.2%), and 33 for 2 to 4 years (22.8%). The mean follow-up time was 7.2 ±3.4 years. No zirconia fractures were identified. Two implants and 2 ISZFDPs failed, with chipping being the most common complication (13.5%). The implant survival rate was 99.4%, and the prosthetic survival rate was 98.2%. The cumulative prosthetic success rate was 91.9%. MBL change was -0.18 ±0.59 mm. Thirteen implants were treated for peri-implantitis (3.8%), and 9 for mucositis (2.7%), but presented healthy peri-implant soft tissues at the follow-up examination. A significant difference was found between the implant-level and abutment-level prostheses (P=.013), with less marginal bone loss observed in ISZFDPs delivered at the implant level. ConclusionsZirconia-based screw-retained implant-supported prosthesis can be considered a reliable long-term treatment option for partial and complete edentulism. No zirconia fractures were experienced. Stable bone levels and low peri-implantitis rates were reported regardless of the ISZFDP type and level, implant type and connection, and type of loading.

Clinical outcomes and complications of posterior three-unit porcelain-fused-to-metal restoration combined with tooth-implant-supported prosthesis: A meta-analysis

Background/purposeThe three-unit bridge that combines a natural tooth and an implant provides extended treatment possibilities for partially edentulous patients. We conducted a systematic review and meta-analysis of clinical trials to evaluate three-unit porcelain-fused-to-metal (PFM) tooth-implant-supported prosthesis (TISP) compared with implant-supported-prosthesis (ISP) reconstruction outcomes and complications. Materials and methodsThe PubMed, Embase, and Cochrane library databases were searched for articles published before February 2021. The meta-analysis used a random-effects model to calculate overall effect size. The study was registered with PROSPERO (number: CRD 42021232606). ResultsSeven articles published between 2004 and 2015, with sample sizes ranging from 10 to 250 patients were included. No significant difference in the prosthesis failure rate, implant failure rate, prosthesis technical complication rate, implant technical complication rate, and marginal bone level change was observed between the TISP group and the ISP group. In TISP group, natural tooth failure rate was reported to range from 0% to 4.3%, biological complication related to the natural tooth was reported to range from 0% to 26.9%, and no trial reported natural tooth intrusion. ConclusionThe three-unit short-span TISP is a potentially reliable treatment option for patients with missing posterior teeth.