How to avoid intraoperative and postoperative complications in maxillary sinus elevation

Maxillary sinus floor elevation, via the lateral approach, is one of the most predictable bone augmentation procedures performed in implant dentistry. but both intra- and postoperative complications can occur, and some of them are severe. Our aim is as follows: To review the pertinent literature on the topic, especially assessing the risk factors related to complications. To give clinical recommendations to minimize intra- and postoperative complications with the ultimate scope of improving the standard of clinical care and patient safety.

Marginal bone loss around dental implants: comparison between diabetic and non-diabetic patients-a retrospective clinical study

OBJECTIVES

The aim of the present retrospective study was to compare the marginal bone loss (MBL) around dental implants in a group of diabetic patients in relation to a matched group of non-diabetic patients.

MATERIALS AND METHODS

The present dental record-based retrospective study included patients selected from individuals treated with dental implants at one specialist clinic in Malmö, Sweden. Patients were excluded if they had history of periodontitis and/or were treated for periodontal disease. The study group included 710 implants installed in 180 patients (mean age 60.3±13.0 years), 349 implants in 90 diabetic (21 T1DM and 69 T2DM patients), and 361 implants in 90 non-diabetic patients.

RESULTS

The results suggested that jaw (greater MBL in the maxilla), diabetes (greater MBL for diabetic patients, and worse for T1DM patients), bruxism (greater MBL for bruxers), and smoking (greater MBL for smokers and former smokers) had a statistically significant influence on MBL over time.

CONCLUSIONS

Patients with diabetes have an estimated greater MBL over time compared to non-diabetic patients. The difference was greater in patients with diabetes type 1 compared to patients with diabetes type 2. Bruxism, smoking, and implant location (maxilla) were also associated with a higher loss of marginal bone around implants over time.

CLINICAL RELEVANCE

Awareness of the possible influence of diabetes on the long-term outcomes of dental implant treatment is important, in order to be able to minimize the possibility of a high MBL with time, which can eventually lead to the loss of the implant.

Midfacial Soft Tissue Recession Following Immediate Implant Placement with Bone Grafting in the Esthetic Area: A Systematic Review and Meta-analysis

Purpose: To systematically analyze the outcomes of immediate implant placement (IIP) with bone grafting in the esthetic area. Materials and Methods: PubMed, Embase, and Cochrane CENTRAL were searched. Prospective studies reporting midfacial soft tissue recession (primary outcome) of single-tooth IIP with bone grafting in the esthetic area were included. Risks of bias were assessed. Meta-analysis, sensitivity analysis, and meta-regression were undertaken. Results: A total of 13 studies and 421 patients were included, with a follow-up length of 1 to 10 years in function. The weighted mean (95% CI) of midfacial soft tissue recession was 0.33 (0.21, 0.46) mm and 0.54 (0.16, 0.93) mm after 1 year and 5 years in function. Meta-regression indicated that after 1 year in function, there was 0.33 mm less midfacial soft tissue recession with soft tissue grafting (P = .021), while there was 0.58 mm more soft tissue recession (P = .007) in defect extraction sockets. Implant survival was 97.8%, and all failures were early failures. Peri-implant soft and hard tissue stability, peri-implant health, esthetic outcomes, and patient satisfaction were predictable within the follow-up period. Conclusion: Midfacial soft tissue recession showed an ongoing status in IIP with bone grafting in the esthetic area within 5 years in function. For extraction sockets with a thin gingival biotype or deficient buccal bone wall, soft tissue grafting was recommended.

Influence of different mucosal phenotype on early and long-term marginal bone loss around implants: a systematic review and meta-analysis

OBJECTIVES

To investigate the influence of different mucosal phenotypes on peri-implant marginal bone loss.

MATERIALS AND METHODS

The search was conducted in five databases including PubMed, Embase, Cochrane, Scopus, and Web of Science (until 1st Sept. 2022) to identify relevant clinical studies. Potentially relevant journals were also manually searched. Two reviewers independently screened studies, extracted data, and evaluated the quality of the studies. Prospective clinical trials and observational studies investigating peri-implant marginal bone loss in thick-mucosa and thin-mucosa groups were included.

RESULTS

A total of 14 studies were included in this systematic review. Results of the meta-analysis revealed a weighted mean difference of 0.38 mm for marginal bone loss between thick- and thin-mucosa groups (95% confidence interval = 0.02-0.74, P = 0.002). Statistical significance existed in short-term (follow-up ≤ 1 year) data (WMD = 0.41 mm, 95%CI = 0.11-0.70, P = 0.007), but not in long term (follow-up ≥ 3 y) data (WMD = 0.17 mm, 95%CI = - 0.02-0.36, P = 0.07). Survival rate revealed no difference between thick and thin mucosa groups. In subgroup analyses, a positive association between thick mucosa and less marginal bone loss was found in the non-submerged group, cement-retained group, and bone-level group.

CONCLUSIONS

A significantly less marginal bone loss occurred in implants with thick mucosa than with thin mucosa in the short term, whereas no significant difference was observed in the long term. Due to the substantial heterogeneity and limited long-term data, further high-quality evidence is warranted to confirm the results.

CLINICAL RELEVANCE

Clinicians are advised to use caution in treating patients with thin mucosa and adhere closely to indications and protocols to minimize marginal bone loss.

Influence of Platform-Switched Restoration on Bone Resorption in Patients Treated with Wide-Diameter, External-Hex-Connection Dental Implants: A 10-Year Follow-up Study

Purpose: To investigate and assess the differences in crestal bone loss (CBL) between wide-diameter, external-hexagon-connection implants restored with platform-switching (PS) and platform-matching (PM) restorations with a follow-up of 10 years. Materials and Methods: This study retrospectively analyzed the updated and enlarged dataset of a 5-year prospective clinical study at 10-year follow-up. The data concerns 182 healthy adult subjects treated in a private dental practice who received a single wide-diameter implant with an external hexagon connection in the molar area, restored with either a PS restoration (test) or PM restoration (control). The amount of CBL was radiographically measured at each annual follow-up, as well as after 5 and 10 years of implant loading. In evaluating the association between the two types of abutments and bone loss (including change over time), a linear mixed effects model was run for longitudinal data. Results: Implants connected with PS restorations exhibited significantly lower reduction (0.25 mm) in CBL than those joined to PM restorations (P < .001; 95% CI from 0.22 to 0.29). However, both groups presented a higher increase in bone loss during the first year (0.58 mm in PS and 0.83 mm in PM) and a linear increment thereafter until the 10-year follow-up (0.046 mm/year; P < .001; 95% CI from .042 to .049). Conclusion: Notwithstanding the limitations of this study, it can be concluded that after 10 years of follow-up, the implant with a wide diameter and external-hexagon connection restored with a PS abutment seems to be more effective in reducing bone loss compared with the PM abutment.

Intraoperative complications and early implant failure after transcrestal sinus floor elevation with residual bone height ≤5 mm: A retrospective multicenter study

OBJECTIVE

Clinical indications for maxillary sinus floor elevation with transcrestal techniques have increased in recent years even in sites with minimal residual bone height (RBH). Nevertheless, limited information is currently available on incidence of intraoperative complications and early implant failure in these cases.

MATERIAL AND METHODS

This retrospective multicenter study was performed on anonymized clinical and radiographic records of patients who underwent transcrestal sinus floor elevation in seven clinical centers. Influence of different factors related to patient, and sinus anatomy and surgical technique on the incidence of intraoperative complications and early implant failure rate after transcrestal sinus lift were investigated.

RESULTS

A total of 430 patients treated with transcrestal sinus floor elevation for single-implant insertion in sites with RBH ≤5 mm were included in the final analysis. After 1 year of loading, 418 implants of 430 were satisfactorily in function. Early implant failure was recorded in 12 cases (2.8%); results were significantly associated with the presence of large sinus cavities and with the occurrence of membrane perforation. The following adverse events were recorded: membrane perforation (7.2%), acute sinusitis (0.9%), implant displacement into the sinus cavity (0.7%), oro-antral fistula (0.2%), and benign paroxysmal positional vertigo (0.5% of osteotome cases). A strong direct correlation between sinus membrane perforation and bucco-palatal sinus width (p = .000) was demonstrated.

CONCLUSIONS

Early implant failure after transcrestal sinus elevation showed significant direct correlation with bucco-palatal maxillary sinus width and the presence of membrane perforation. Sinus membrane perforation was strongly associated with bucco-palatal sinus width (extremely low perforation rate in narrow and much higher incidence in wide sinuses).

Low Window Sinus Elevation Technique: Bone Gain and Postsurgical Discomfort. A Retrospective Case Series

Recently, the Low Window technique was proposed to facilitate sinus augmentation and reduce postsurgical patient discomfort. It was shown to be both safe and effective. This case series evaluates the postsurgical discomfort of patients undergoing Low Window sinus augmentation, the bone gain achieved, and whether these factors correlate with the osteotomy area. Records of patients (n = 26) who underwent a sinus elevation using the Low Window approach (n = 34 interventions), followed by implant placement and prosthetic rehabilitation (n = 97 implants), were assessed retrospectively. The analyzed outcomes were the medial, middle, and lateral bone gain ≥ 9 months after augmentation; pain at 5 to 6 hours postsurgery, evaluated on a visual analog scale (VAS; 0 to 100); pain, swelling, and hematoma formation every day up to 7 days postsurgery, evaluated by VAS; implant and prosthetic success and survival rates; and rate of complications. The average follow-up time was 62.1 ± 14.9 months. No intraoperative sinus membrane perforations or other complications occurred. Medial, middle, and lateral bone gains were 10.1 ± 1.7 mm, 11.6 ± 0.8 mm, and 10.7 ± 0.9 mm, respectively. At the last follow-up, the implant success rate was 99%. Postsurgical VAS pain 5 to 6 hours postsurgery was 12.3 ± 8.0 and decreased significantly thereafter. Swelling prevalence was 29.4% at 1 day postsurgery, 20.6% at 2 days, and 2.9% the following day. No swelling was observed from day 4 onward. Prevalence of hematoma was 8.8% for 2 days postsurgery, 2.9% the day after, and no hematoma was observed thereafter. Only the osteotomy area correlated with immediate postsurgical pain, but not with other discomfort outcomes or with bone gain. Low Window sinus elevation might allow bone gain and medium-term implant and prosthetic success rates similar to that of other access window designs. Prospective, comparative studies are needed to investigate whether the technique is more advantageous than traditional approaches.

Incidence of Sinus Membrane Perforation Using Two Types of Implant Drills: An Ex Vivo Animal Study

This ex vivo study evaluates the incidence of sinus membrane perforation during implant site osteotomy with two different types of drills and drilling techniques. Fifty goat heads with 50 sinus pairs (100 sinus sides) were assigned to two groups (osseodensification bur [OB] group and inverse conical shape bur [ICSB] group) to simulate transcrestal sinus elevation (50 sinus sides per group). An osteotomy was performed to pass through the lateral sinus wall no more than 3 mm. The integrity of the sinus membranes was examined and confirmed under a microscope. Of the 50 sinuses per group, the OB group presented with 14 (28%) perforated sinuses, while the ICSB group presented with 2 (4%) perforated sinuses. Of the 14 perforations from the OB group, 6 (42.9%) showed a pinpoint perforation pattern, 4 (28.5%) of which were not visible until direct air pressure was applied. Overall, the ICSB drill group demonstrated a lower sinus perforation rate than the OB group.

Failure of Dental Implants and Associated Risk Factors in a University Setting

PURPOSE

To assess the cumulative failure rate of 4,842 implants comprising six commercial implant brands in a university setting, and to evaluate the influence of different risk factors on the implant failure rate.

MATERIALS AND METHODS

A retrospective chart review was conducted in patients receiving dental implants at the School of Dentistry of the International University of Catalonia (Barcelona, Spain) from 2011 to 2018. The inclusion criterion was patients presenting at least one failed implant.

RESULTS

The cohort study included 1,510 patients who received a total of 4,842 implants. The cumulative failure rate was 4.9% and 10.8% at the implant and patient levels, respectively. The multiple regression analysis showed that for the same number of implants per patient, variables such as age and sex were not associated with higher implant failure rates. Furthermore, in considering the combination of arch-sector, a statistically significant reduction in failure rate was observed in the posterior maxilla (OR = 0.66, P = .038) and in the posterior mandible (OR = 0.64, P = .037). The results showed all implant brands offering high implant survival rates (> 91%). Nobel Biocare and Straumann implants significantly reduced the risk of implant failure (OR = 0.37, P = .021 and OR = 0.53, P = .024, respectively), while no significant differences were recorded among Klockner (2.8%), MIS (5.4%), Biomet 3i (7.1%), and Astra Tech (8.4%; P ≥ .05). No association was found between implant loss and bone augmentation, time of implant placement, smoking, and history of periodontal disease.

CONCLUSION

The implant failure rates obtained in a university setting resulted in overall cumulative rates of 4.9% and 10.8% at the implant and patient levels, respectively, over a 7-year period. Male sex and implants placed in the anterior mandible may be associated with a higher risk of implant failure. Nobel Biocare and Straumann implants seem to positively affect implant survival rate.

Effect of antibiotic prophylaxis in dental implant surgery: A multicenter placebo-controlled double-blinded randomized clinical trial

BACKGROUND

The growing resistance of bacteria to antimicrobial medicines is a global issue and a direct threat to human health. Despite this, antibiotic prophylaxis is often still routinely used in dental implant surgery to prevent bacterial infection and early implant failure, despite unclear benefits. There is a lack of sufficient evidence to formulate clear clinical guidelines and therefore there is a need for well-designed, large-scale randomized controlled trials to determine the effect of antibiotic prophylaxis.

PURPOSE

To compare the effect of a presurgical antibiotic regimen with an identical placebo regimen in healthy or relatively healthy patients receiving dental implants.

MATERIALS AND METHODS

The 474 patients participating in the study were recruited from seven clinics in southern Sweden. We randomized the patients into a test and a placebo group; the study was conducted double-blinded. Preoperatively, the test group received 2 g of amoxicillin and the control group, identical placebo tablets. The primary outcome was implant failure; secondary outcomes were postoperative infections and adverse events. Patients were evaluated at two follow-ups: at 7-14 days and at 3-6 months.

RESULTS

Postoperative evaluations of the antibiotic (n = 238) and the placebo (n = 235) groups noted implant failures (antibiotic group: six patients, 2.5% and placebo group: seven patients, 3.0%) and postoperative infections (antibiotic group: two patients, 0.8% and placebo group: five patients, 2.1%). No patient reported any adverse events. Between-group differences in implant failures and postoperative infections were nonsignificant.

CONCLUSION

Antibiotic prophylaxis in conjunction with implant placement is likely of small benefit and should thus be avoided in most cases, especially given the unabated growth in antibiotic-resistant bacteria.

CLINICAL TRIAL REGISTRATION NUMBER

NCT03412305.

[Relationship between dental implant mucosa and dental implant papilla levels and peri-implant soft tissue stability]

PURPOSE

To investigate the relationship between dental implant mucosa (DIM) and dental implant papilla (DIP) levels and peri-implant soft tissue stability.

METHODS

A total of 86 patients with tooth implant in Qingdao Haici Hospital from January 2015 to January 2019 were enrolled, the patients were followed up from initial treatment till December 2020. Various indexes were recorded at the implantation moment(T0), 4 weeks(T1), 2 years(T2) after implantation and end of follow up (T3), including marginal bone loss levels (MBLs), mid-buccal mucosal levels (MBMLs), modified sulcus bleeding index(mSBI), modified bleeding index(mBI) and implant stability quotient (ISQ). Then the correlation of those indexes was analyzed. SPSS 23.0 software package was used to analyze the data.

RESULTS

The follow-up period was 1.0-5.2 years, with an average of (4.79±0.34) years; two cases were lost to follow up, and finally 84 cases (95 implants) were included. Compared with indexes at T0, mSBI, mPLI, mBI, the level of distal bone adjacent to the tooth contact point, and the middle bone level adjacent to the tooth contact point at T1, T2, and T3 decreased significantly(P＜0.05), and DIP height increased significantly; PD, MBLs and MBMLs at T0, T1, T2, and T3 showed no significant difference(P＞0.05). The level of distal bone adjacent to the tooth contact point, and the middle bone level adjacent to the tooth contact point had an impact on DIP(P＜0.05). There were 49 cases with papillae gain in height and 46 cases with papilla that lost height. ISQ of gain height group and loss height group was relatively high at T0(P＜0.05). Compared with T2, there was a decrease in ISQ in both groups at T1(P＜0.05). ISQ of gain height group was significantly higher than that of loss height group at T1 and T2 (P＜0.05).

CONCLUSIONS

There is a dependent correction between dental implant mucosa and dental implant papilla levels, and the stability of peri-implant soft tissues depends on keratinized tissue height and DIP height.

Long-Term Results of Intraforaminal Immediately Loaded Implants and Posterior Mandibular Regrowth Evaluation in Severely Atrophic Mandibles

PURPOSE

The aim of this clinical study was to verify the predictability of the rehabilitation of extremely atrophic jaws with immediately loaded short implants and evaluate posterior mandibular regrowth.

MATERIALS AND METHODS

A cohort of consecutive fully edentulous patients wearing complete dentures in both arches was enrolled. Periodically, implant survival and prosthetic success were assessed. After informed consent, a subsample of 10 patients who had preoperative CBCT underwent a postoperative CBCT 1 year after immediate implant loading, and 3D superimpositions of pre- and postoperative images were performed. Linear measurements of bone height were performed at two sites in each hemimandible and, on the same sections, bone density according to the qualitative gray values (GVs) was analyzed in an area of 3 mm² including the cortical mandibular bone.

RESULTS

Fifty-nine fully edentulous patients (31 females, 28 males) with Class VI atrophic mandibles according to Cawood and Howell were rehabilitated with the insertion of four to five short implants (4-mm diameter, 7- or 8.5-mm long). Overall, 251 implants were immediately loaded with a fixed hybrid prosthesis. Four patients did not show up for recall visits, bringing the final number down to 55 patients (31 females, 24 males) and 231 implants. In up to 14 years of follow-up, a total of 4 implant failures were recorded (cumulative survival rate, 98.4%). The biologic complications included 9 mucositis (3.9%) and 3 peri-implantitis (1.3%) at implant-level analysis. Mechanical complications involved 9 chippings of the prosthetic restorations (17.0%). In the 10-patient subsample, the analysis showed bone growth (average of 1.2 ± 0.7 mm) in the posterior areas of the mandible. In addition, bone density was found to increase 17% to 27% with reference to the preoperative CBCT.

CONCLUSION

The immediate loading of short implants may represent a feasible therapeutic option for the treatment of fully edentulous patients with severely atrophic mandibles. Bone regrowth in the posterior areas and an increase in bone density of the mandible may occur.

The Effect of Initial Biologic Width on Marginal Bone Loss: A Retrospective Study

PURPOSE

To evaluate the short-term effect of dental implant placement, mucosa thickness, and their combined effects (initial biologic width) on marginal bone loss.

MATERIALS AND METHODS

This was a retrospective study on patients who received implant surgery in the posterior region without bone augmentation surgery between 2012 and 2016, and implants had been loaded for more than 12 months. Each patient received radiographic examination before and after implant surgery, before the stage-two surgery, and during the 1- to 5-year follow-up. The thickness of mucosa, depth of dental implant placement, and crestal bone loss were evaluated on digital radiographs. The interaction was discussed by defining the combination of initial mucosal thickness and implantation depth as the initial biologic width. The implants were divided into four study groups based on the quartile of the initial biologic width.

RESULTS

This study included 266 patients (94 male and 172 female, 22 to 85 years of age, mean age: 51.43 years), with 413 dental implants placed including 239 Straumann implants and 174 Ankylos implants. The average follow-up was 21.50 months. After 1 to 5 years, the median crestal bone loss around implants was 0.35 mm (0.30 mm for Straumann BL and 0.40 mm for Ankylos). The implants were divided into four groups: group A (≤ 2.85 mm), group B (2.85 to 3.40 mm), group C (3.40 to 3.97 mm), and group D (> 3.97 mm). Group B showed significantly less crestal bone loss than group A (0.38 mm vs 0.25 mm; P < .05) and group C (0.25 mm vs 0.40 mm; P < .05) during the follow-up. Significantly more crestal bone loss around implants was observed in the thin mucosa group than in the thick mucosa group (0.50 mm vs 0.30 mm; P < .001), while implants placed beneath the bone level displayed a significantly higher amount of marginal bone loss than implants placed even with the bone crest (0.50 mm vs 0.10 mm; P < .001).

CONCLUSION

The initial biologic width has an effect on crestal bone loss. When the initial biologic width was between 2.85 and 3.40 mm, the marginal bone loss was lowest. Based on radiographic evaluation, implants placed in thick gingiva and even with the bone level showed less alveolar marginal bone loss compared with implants placed in thin gingiva and below the crestal bone level.

Does the serum level of vitamin D affect marginal bone loss around dental implants?

Vitamin D is effective in bone healing. The aim of this study was to assess marginal bone loss (MBL) around dental implants in patients with sufficient and insufficient serum levels of vitamin D. This was a prospective cohort study with a pre-protocol population. Patients who underwent dental implantation in the first or second molar region and had a long-cone peri-apical digital radiograph taken at the time of loading and 12 months later were studied. Patients were assigned to one of three groups based on their serum vitamin D level: group 1, the serum level of vitamin D was deficient, group 2 insufficient, and group 3 sufficient. The marginal bone level change from immediately after loading to 12 months later was considered as MBL. Analysis of variance (ANOVA) was applied to compare MBL between the three groups. Ninety patients were included (30 in each group). The mean MBL was 1.38 ± 0.33 mm in group 1, 0.89 ± 0.16 mm in group 2, and 0.78 ± 0.12 mm in group 3. Analysis of the data demonstrated a significant difference in the mean MBL among the three groups (P < 0.001). There was a correlation between MBL and vitamin D serum levels (P < 0.001). It appears that a low serum level of vitamin D may be associated with increased MBL.

Severe Complications Following Maxillary Sinus Augmentation Using Poly L-lactide-co-ε-caprolactone-Coated Bovine Bone: A Retrospective Study

PURPOSE

To describe the postoperative complications following lateral wall sinus augmentation using (poly L-lactideco-ε-caprolactone; PLCL) and natural polysaccharides polymers-coated bovine bone (PBB). The secondary aims were to examine histologic findings and to propose complication management alternatives.

MATERIALS AND METHODS

This retrospective study included 61 subjects who underwent 67 lateral wall sinus augmentation procedures using PBB in the standard protocol. In cases that presented complications, treatment included additional antibiotic therapy, implant removal, or sinus reentry and total removal of the grafting material. In three cases, biopsy specimens were taken from the sinuses, and histologic analyses were performed.

RESULTS

The prevalence of postoperative complications was 32.8% (22 of 67 cases) in 18 of the patients (29.5%). The most prevalent symptoms were persistent pain (68.2%), swelling (63.6%), and oroantral fistula (54.5%). Radiographic signs appeared in 45.5% of the complications. A total of 24 implants failed; thus, an overall 80.3% survival rate was established at 19 months. The vast majority of complications (86.4%) were treated eventually with reentry surgery and revealed that the sinus was full with granulation tissue surrounding pieces of a nonossified rubber-like material. In cases where implants were placed, nonosseointegrated implants were surrounded by soft tissue. The sinus was cleaned thoroughly; the graft material remnants were removed together with inflamed parts of the sinus membrane, followed by chlorhexidine and saline lavages. In the biopsy specimens taken from the sinus cavity, there were no histologic features of new bone formation around the grafted material.

CONCLUSION

Lateral wall maxillary sinus augmentation using PBB was associated with an acute sinus infection histologic appearance and with a 7-times-higher failure rate compared with previous reports. This serious adverse event suggests that PBB cannot be recommended for maxillary sinus augmentations.

Marginal Bone and Keratinized Mucosa Alterations Around Sloped Implants Placed in Healed Sloped Crests: A Long-Term Cohort Study

To improve the adaptation to bone level discrepancies of sloped alveolar crests, an implant with a sloped implant-abutment interface has been developed. In a previously reported international multicenter study, 65 sloped implants replaced single teeth with a buccolingual bone level discrepancy at least 3 months after tooth loss. The present study reports the long-term outcomes of one study center and also evaluates marginal bone and keratinized mucosa alterations around sloped implants in healed, sloped crests in a long-term follow-up. Implant survival, marginal bone levels, and buccal bone dimensions in relation to the implant shoulder level (assessed by periapical radiographs and CBCT), width of keratinized mucosa, and probing depths were observed. Two patients did not present for follow-up examinations. No implants were lost. The remaining 13 implants were followed for a mean period of 123 months. Mean marginal bone levels were maintained slightly coronal to implant shoulder level at the interproximal (0.13 mm) and the buccal aspects (0.57 mm). The width of keratinized mucosa improved significantly from delivery (1.85 mm) to the 1-year follow-up (3.39 mm) and was thereafter unchanged. Placing implants with a sloped shoulder in a healed crest with lingual-buccal bone level discrepancy resulted in circumferential marginal bone maintenance and improved width of the keratinized mucosa.

Long-Term Outcomes of Implants Placed in Autogenous Onlay Bone Grafts Harvested from Mandibular Ramus and Risk Analysis

PURPOSE

This study evaluated the long-term survival and success rates of dental implants placed with autogenous onlay block bone grafts harvested from the mandibular ramus.

MATERIALS AND METHODS

Patients treated with onlay bone graft from the mandibular ramus due to a severe vertical alveolar defect from 2001 to 2017 were included in this study. The marginal bone loss, success, and survival time of the implants were recorded and analyzed with clinical factors, such as time from bone graft to implant placement, type of implant prosthesis connection, history of periodontitis, and insertion depth.

RESULTS

Seventy-five implants in 40 onlay bone-grafted areas of 38 patients were included, with a mean follow-up period of 102 months (range: 14 to 192 months). Two grafts were removed before implant placement. Of the 75 implants, 11 implants were lost. History of periodontitis and marginal bone loss at 6 months after implant placement were significantly associated with implant success. The receiver operating characteristic curve showed that a marginal bone loss of 0.75 mm after 6 months of implant placement was related to implant success, with a sensitivity of 72.2% and specificity of 89.6%.

CONCLUSION

Implants placed with onlay bone graft from ramal bone had more frequent biologic complications, and failures may be predicted by measuring the amount of implant bone loss after 6 months of placement.

Efficacy of bone-substitute materials use in immediate dental implant placement: A systematic review and meta-analysis

OBJECTIVE

To assess the efficacy of using a bone substitute material (BSM) in the fixture-socket gap in patients undergoing tooth extraction and immediate implant placement.

MATERIALS AND METHODS

MEDLINE, EMBASE, and CENTRAL databases were searched for randomized controlled trials (RCTs). RCTs were screened for eligibility, and data were extracted by two authors independently. Risk of bias (ROB) was assessed using Cochrane's ROB tool 2.0. Primary outcomes were implant failure, overall complications, and soft-tissue esthetics. Secondary outcomes were vertical buccal bone resorption, vertical interproximal bone resorption, horizontal buccal bone resorption, and mid-buccal mucosal recession. Meta-analysis was performed using random-effects model with generic inverse variance weighing. GRADE was used to grade the certainty of the evidence.

RESULTS

After screening 19 544 potentially eligible references, 20 RCTs were included in this review, with a total of 848 patients (916 sites). Most included RCTs were deemed of some concerns (53%) or at low (38%) risk of bias, except for overall complications (high ROB). Implant failure did not differ significantly RR = 0.92 (confidence intervals [CI] 0.34 to 2.46) between using a BSM compared with not using a BSM (NoBSM). BSM use resulted in less horizontal buccal bone resorption (MD = -0.52 mm [95% CI -0.74 to -0.30]), a higher esthetic score (MD = 1.49 [95% CI 0.46 to 2.53]), but also more complications (RR = 3.50 [95% CI 1.11 to 11.1] compared with NoBSM. Too few trials compared types of BSMs against each other to allow for pooled analyses. The certainty of the evidence was considered moderate for all outcomes except implant failure (low), overall complications (very low), and vertical interproximal bone resorption (very low).

CONCLUSION

BSM use during immediate implant placement reduces horizontal buccal bone resorption and improves the periimplant soft-tissue esthetics. Although BSM use increases the risk of predominantly minor complications.

Long-Term Esthetic Complications Associated With Anterior Implant-Supported Restorations

Having demonstrated high average survival rates, osseointegrated endosseous dental implants are considered a predictable solution for the replacement of missing teeth. Most studies and case reports have concentrated on the success and/or failure of dental implant-supported restorations in the posterior regions of the mouth, while fewer reports have investigated the performance of such treatments in the esthetic segment. Today, it is recognized that in addition to implant survival, other parameters of implant dentistry are considerations when evaluating success or failure in the esthetic zone. These include numerous patient and operator assessments of peri-implant soft-tissue level, prosthesis level, subjective smile and esthetic appearance, and phonetic changes. Implant dentistry in the esthetic zone is highly challenging because of not only the immediate postoperative appearance, but also the potential changes that might occur in the long term, such as soft- and hard-tissue recessions, infraocclusion of single implants adjacent to natural teeth, and the unpredictable development of peri-implantitis. Thus, the aim of this article is to identify possible long-term biologic complications that may develop around dental implant in the esthetic zone and discuss their effect on treatment decisions.

Inferior alveolar nerve injury following dental implant placement: A medicolegal analysis of French liability lawsuits

AIMS

This study thus aimed to review and analyze liability lawsuits resulting from implant surgery-related inferior alveolar nerve (IAN) injury over a twenty-year period in France.

MATERIALS AND METHODS

A retrospective descriptive study was performed to analyze judicial decisions pertaining to IAN injury from a legal database between 2000 and 2020. Inclusion criteria comprised all closed malpractice cases that involved an oral and maxillofacial surgeon or a dentist who performed a mandibular implant surgery resulting in IAN injury. The following data were recorded: judicial decision reference (including jurisdiction and date of final court ruling), timing between the incident and final court ruling, number of involved practitioners, patient's age and gender, practitioner's age and gender, implant type, number of implants, location of iatrogenic implant(s), allegation of IAN injury, alleged cause of injury, justification(s) for conviction, compensation amount and legal costs.

RESULTS

Twelve judicial decisions from high civil courts relating to ten closed cases of liability lawsuits were included and analyzed. All of involved practitioners were dentists or oral surgeons, working in the private sector. Eventually, 85% of them were convicted. Mean indemnification was 17,340€ and highest indemnification was 42,828€ (inflation-adjusted in 2020 euros). Mean interval between the incident and final ruling was 87,1 ± 34,2 months.

CONCLUSIONS

Permanent nerve injury following dental implant placement can result in legal action. In the event of lawsuit, the risk of being convicted is high. Practitioners performing oral implantology procedures should practice effective risk management to avoid time-consuming unwanted litigations and administrative proceedings.

Implants Placed in Adolescents Followed for Up to 15.5 Years: A Retrospective Case Series

PURPOSE

To evaluate the clinical outcomes of unsplinted implant-supported single crowns placed in adolescents, ages 10 to 19 years, and followed up from 5 to 15 years.

MATERIALS AND METHODS

This retrospective case series evaluated the outcomes of implant-supported single crowns placed in adolescents between June 2002 and January 2015. The patients were treated with locking-taper connection implants under a two-stage rehabilitation technique. The variables assessed included patient identification, age and reason for implant placement, implant dimensions, follow-up time, status at follow-up, and event description. To analyze peri-implant changes, bone crest level relative to the adjacent tooth was measured from periapical radiographs taken after implantation and the latest follow-up. A paired t test was performed to determine initial and follow-up differences, and data are shown as mean and 95% confidence interval. Cumulative Kaplan-Meier survival rates for implants and prostheses were calculated.

RESULTS

Twenty-one adolescent patients with ages ranging from 14 to 19 years, mainly 16 to 18 years, received a total of 37 implant-supported single crowns more frequently placed in the anterior maxilla as a result of congenital aplasia and trauma. Mean changes in bone crests were 1.99 (± 0.4) mm at the day of crown insertion and 2.23 (± 0.4) mm at the latest follow-up (average: 10 years; P = .08). No implant was lost during the follow-up period, leading to 100% implant survival. A total of 34 surviving crowns and 3 crown failures at the time of the latest follow-up led to a cumulative survival rate of 70%. The most commonly observed event was loss of proximal contacts and infraocclusion, which were handled chairside by adding resin composite.

CONCLUSION

Unsplinted implant-supported single crowns placed in adolescents showed high implant and prosthesis survival rates, with a mean bone crest level increase of approximately 0.23 mm relative to the adjacent teeth.

Psychologic Status and Influence of Surgery Techniques on Acute Nonneuropathic Pain After Dental Implant Surgery: Systematic Review and Meta-analyses

PURPOSE

Dental implant placement is often followed by acute pain, which is one of the most important patient-centered matters of treatment. However, this pain is often not adequately appreciated by clinicians, and knowledge about risk factors associated with acute pain is scant. An understanding of these factors is important to help clinicians deliver efficient pain control advice based on individual demand.

MATERIALS AND METHODS

A systematic review of the literature was carried out to identify published risk factors for acute pain after dental implant surgery. PubMed, Cochrane Central Register of Controlled Trials, Embase, and Google Scholar databases were searched to find pertinent studies up to August 2019. Cohorts and randomized controlled trials (RCTs; including split-mouth trials) were included. The criteria used were those described in the PRISMA statement for performing systematic reviews.

RESULTS

Nine hundred twenty-five papers were identified through the initial searching. After three stages of screening, 38 articles were included in the qualitative analysis but only 8 in the quantitative analysis. Despite the heterogeneity of the included articles, these data showed that flapped (vs flapless) surgery, anxiety, longer surgical duration, anticipation of more pain before surgery, and higher pain levels at earlier time points play a key role in the intensity of acute pain after dental implant surgery. There is strong evidence to suggest that the place of insertion (maxilla/mandible) is not a risk factor for pain.

CONCLUSION

The results for the effect of immediate loading (vs delayed loading), number of implants inserted, sex, age, and smoking on pain were inconclusive.

Risk Factors for Dental Implant Failure in Private Practice: A Multicenter Survival Analysis

PURPOSE

The objective of this study was to quantify the probability of implant failure over time from intrinsic patient factors using a population of patients from multiple private practices.

MATERIALS AND METHODS

The records for this retrospective, multicenter cohort study were randomly selected from eight private practices. The primary outcome variable was time to event (implant failure or last known follow-up). The included independent variables were age, sex, diabetes status, smoking status, and arch location. Analyses were performed with Cox proportional hazards on three models: univariate, full multivariate, and systemic factor multivariate. The probability of implant survival at 1, 5, and 10 years was calculated using univariate time-to-event modeling on log-normal distribution with 95% CIs and Cox proportional hazard tests for significance. The Kaplan-Meier survival curve was calculated for patients < 71 years of age.

RESULTS

Eight hundred thirty-five implant-level records from 378 patients were collected for analyses. The mean patient age was 60 years, and 48% were men, 15% reported a history of smoking, and 16% reported having diabetes. The follow-up time was as long as 17 years, with a mean of 23.1 months, and a median of 7 months. The hazard ratio (HR) for implant failure due to sex (HR = 1.18; 95% CI: 0.52 to 2.66), smoking (HR = 1.30; 95% CI: 0.49 to 3.46), diabetes (HR = 1.17; 95% CI: 0.35 to 3.86), and arch location (HR = 2.13 to 3.39) failed to reach the threshold within any Cox proportional hazards model (P > .05).

CONCLUSION

The implant survival probability for patients ≤ 70 years of age is 86.4% at 10 years in the course of routine private practice by experienced providers. Cautious interpretation of these results is critical, as the effects of known systemic risk factors are likely tempered by effective modifications in clinical decisions and protocols with short- and long-term follow-up maintenance.

Marginal Bone Loss of Dental Implants in Patients with Type 2 Diabetes Mellitus with Poorly Controlled HbA1c Values: A Long-Term Retrospective Study

PURPOSE

The objective of this study was to report implant survival rates, marginal bone loss, and the impact of prosthesis type among patients with type 2 diabetes mellitus (DMT2), with high hemoglobin A1C (HbA1c) values.

MATERIALS AND METHODS

This retrospective study utilized patient medical records from an oral surgeon's office. Patients who had moderately or poorly controlled DMT2 with HbA1c values up to 10% were reviewed. Inclusion criteria were partially or fully edentulous patients diagnosed with DMT2 who were subsequently treated with implant-supported prosthetic restorations. Patients were at least 18 years of age. Exclusion criteria were patients who did not present for annual follow-up visits, patient records with incomplete surgical or restorative data, or nondiagnostic radiographs. All the fixed restorations were cement-retained, and the removable restorations were supported by two to six implants. Marginal bone loss and the consequences of prosthetic type were assessed from the last available radiograph compared with the one taken after the surgical procedure.

RESULTS

Data of 357 implants were extracted from the records of 38 patients with HbA1c values (6.9% to 10.0%). The mean follow-up was 7.3 years, with a minimum of 5 years. Six implants failed, yielding a 98.4% overall implant survival rate. The patients were divided into two groups according to the HbA1c values before implant placement. The moderately controlled group included 25 patients with DMT2, with HbA1c values of 6.9% to 8.0%, and the poorly controlled group included 13 patients, with HbA1c values of 8.1% to 10.0%. The overall mean bone loss was 2.02 ± 2.43 mm. In both groups, the maxilla demonstrated more bone loss than the mandible (P < .05). Marginal bone loss in moderately controlled and poorly controlled groups was 1.86 (± 2.21) mm and 2.33 (± 2.85) mm, respectively (P < .05). Removable prostheses also revealed greater bone loss rates compared with fixed prostheses in both groups (P < .05).

CONCLUSION

Patients with high HbA1c values (8.1% to 10.0%) had more marginal bone loss than those with lower HbA1c values. Removable dentures should be reconsidered as a standard treatment option in these patients.

Three-Year Evaluation of the Influence of Implant Surfaces on Implant Failure and Peri-implantitis: A Double-Blind Randomized Controlled Trial with Split-Mouth Design

PURPOSE

To compare the onset of peri-implantitis, incidence of failure, and peri-implant marginal bone level changes between implants with a roughened surface and those with a machined/turned surface.

MATERIALS AND METHODS

All patients needing two dental implants of the same size on the left and right sides of the same arch, and not scheduled for immediate loading, were enrolled between October 2012 and February 2016. The patients were randomly allocated either to Nobel Biocare MKIII or Sweden & Martina Outlink2. Rough-surface implants and machined-surface implants were used from each company. After the preparation of two identical implant sites, each implant (rough or machined of the same group) was randomly allocated to the right and left sides of the same patient, following a split-mouth design. Outcome measures were peri-implantitis onset, incidence of failure, and peri-implant marginal bone level changes. Patients were followed up for 3 years after loading.

RESULTS

One hundred fourteen patients were enrolled and treated; nine patients dropped out. Following an intent-to-treat analysis to avoid overestimation, proportions are given related to the initial number of 114 patients. Peri-implantitis incidence was 4.39% for machined implants (5/114), 0.88% for rough implants (1/114), 1.75% in the Nobel Biocare group (2 cases), and 3.51% in the Sweden & Martina group (4 cases). The failure rate was 1.75% in machined implants (2/114), 0.88% in rough implants (1/114), 0.98% in the Nobel Biocare group (1/114), and 1.85% in the Sweden & Martina group (1/114). No statistically significant differences in marginal bone loss were found comparing different surfaces, while marginal bone loss was significantly lower in Nobel Biocare than in Sweden & Martina implants.

CONCLUSION

Based on the results of this study, no significant differences can be demonstrated in either peri-implantitis or failure rate or in marginal bone loss between rough and machined implants. Marginal bone loss was significantly worse in machined-surface Sweden & Martina than in rough-surface Nobel Biocare implants.