Distribution of bone quality in patients receiving endosseous dental implants

Risk factors for Peri-implantitis: An umbrella review of meta-analyses of observational studies and assessment of biases

OBJECTIVES

To perform a comprehensive quantitative and qualitative analysis of the findings from previously published meta-analyses and to assess existing biases.

DATA/SOURCES

A search was conducted for meta-analyses of observational studies investigating the association between any risk factor and peri‑implantitis in PubMed, Scopus, Cochrane Database of Systematic Reviews, and Epistemonikos, from inception until October 2023 (PROSPERO: CRD42024512408).

STUDY SELECTION

From a total of 5002 publications, 51 full-text articles were evaluated for eligibility, and 12 articles that described 41 unique meta-analyses evaluating the association between risk factors and periimplantitis were selected. Among 41 associations, 24 associations were significant. None of the associations were graded as convincing evidence. Two associations, presence of periodontitis (OR = 3.84 [95 % CI 2.58,5.72]) and cigarette smoking (RR=2.07 [95 % CI 1.41,3.04]) were graded as highly suggestive. Eight associations, diabetes mellitus, hyperglycaemia, lack of prophylaxis, history of chronic periodontal disease, ongoing or history of periodontal disease, implants located in the anterior region of the jaw (maxillary and mandibular), osteoprotegerin (OPG) gene polymorphisms, and lack of keratinized mucosal width were graded as suggestive evidence.

CONCLUSIONS

Periodontitis and cigarette smoking are highly suggestive risk factors for peri‑implantitis. The remaining risk factors which are suggestive require more high-quality studies to be performed to upgrade the level of evidence.

CLINICAL SIGNIFICANCE

The highly suggestive and suggestive risk factors for peri‑implantitis summarized in this umbrella review should be rigorously assessed, monitored and managed by clinicians to reduce the risk peri‑implantitis, as well as to form part of the preoperative consent process.

Randomized controlled multi-centre study comparing shorter dental implants (6 mm) to longer dental implants (11-15 mm) in combination with sinus floor elevation procedures: 10-year data

AIM

To compare implant survival and complication rates between shorter and standard-length implants with sinus augmentation and restored with single crowns, at 10 years of loading.

MATERIALS AND METHODS

One-hundred and one patients (137 implants) with a ridge height of 5-7 mm in the posterior maxilla were randomly assigned to two treatment modalities: shorter implants (6 mm) (group short [GS]) or standard-length implants (11-15 mm) with sinus grafting (group graft [GG]). Following the insertion of final restorations, patients were regularly recalled for up to 10 years. Assessed outcomes encompassed implant survival, marginal bone levels (MBLs), biological and technical parameters and patient-reported outcome measures (OHIP-49 = Oral Health Impact Profile). Non-parametric statistical analysis was used to analyse the data.

RESULTS

For the 5- to 10-year follow-up period, 77 patients with 105 implants (GS: 36 patients/48 implants; GG: 41/57) were available for re-examination (drop-out rate 21%). Implant survival rates at the patient level were 96.0% (GS; 2 failures) and 100% (GG) (inter-group p = .24). Median MBLs amounted to 0.00 mm (min 0.00; max 3.25; GS) and 0.00 mm (min 0.00; max 4.55; GG) (inter-group p = .73). Technical complications predominantly occurred within the first 5 years (inter-group p > .05). Peri-implantitis rates were 4.2% (GS) and 13.3% (GG) (intergroup p = .37). Median OHIP-49 scores were 7.00 (0.00; 39.00; GS) and 9.00 (0.00; 196; GG) (inter-group p = .61) at 10 years.

CONCLUSIONS

Based on similar 10-year implant survival rates, reduced patient morbidity and lower costs, the use of shorter dental implants might well serve as an alternative treatment concept to longer implants placed in conjunction with sinus grafting for patients with a limited ridge height in the posterior maxilla. Study register: https://clinicaltrials.gov/ct2/show/NCT01030523.

Influence of risedronate on orthodontic tooth movement in rodents: a systematic review and case report

INTRODUCTION

Bisphosphonates have an inhibitory impact on osteoclastic activity, reducing bone resorption. However, the influence of risedronate on tooth movement is not well-defined.

OBJECTIVE

This systematic review assessed the effect of risedronate intake on orthodontic tooth movement. A case report was also provided.

METHODS

Two independent reviewers searched six databases (PubMed, Web of Science, Ovid, Lilacs, Scopus, and Open Grey). The searches were carried out in April/2020, and an update was set in place in June/2023. Therefore, the searches considered a timeline from the databases' inception date until June/2023, with no publication date and/or language restrictions. The clinical question focused on evaluating the orthodontic tooth movement and relapse movement (Outcome) in animals (Population) exposed to risedronate (Exposure), compared to control groups (Comparison). The Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) guidelines were applied, and the protocol was registered in PROSPERO (CRD42020168581). The risk of bias was determined using the Systematic Review Centre for Laboratory Animal Experimentation protocol (SYRCLE).

RESULTS

Two studies in rats and one in guinea pigs were included in the systematic review. The studies reported a decrease in orthodontic tooth movement, a reduction in the relapse movement, and a reduced number of positive tartrate-resistant acid phosphatase (TRAP) cells, with a significantly reduced number of bone gaps after the administration of risedronate in rats. A case report illustrated the effects of risedronate administration in one patient.

CONCLUSION

Based on the systematic review, risedronate seems to impair orthodontic tooth movement and relapse due to a decrease in bone resorption cells.

Radiographic density changes may be associated with overloading and implant loss on short implants: A 5-year analysis of a randomized controlled clinical trial

OBJECTIVES

To analyze changes in radiographic bone density around short implants with and without cantilevers at 5 years post-loading.

MATERIALS AND METHODS

Thirty-six patients with two adjacent posterior missing teeth participated in this randomized controlled clinical trial. All patients were randomly allocated to receive either two short implants (6 mm) with single-unit restorations (group TWO) or one single short implant (6 mm) with a cantilever restoration (group ONE-C). Patients were followed up at 6 months, 1, 3, and 5 years. Radiographic analysis was performed, through an arbitrary gray scale value (GSV) of the peri-implant bone, assessing the changes in radiographic density between groups and between time points. Differences in GSV between groups and over time were calculated using a generalized estimating equation to allow for adjustments for the correlation within individuals and between time points.

RESULTS

At 5 years, 26 patients remained in the study (15 in group ONE-C; 11 in group TWO). Implant survival rates were 80.4% in group TWO and 84.2% in group ONE-C (p = 0.894). The radiographic analysis revealed that GSVs increased in both groups over time (p < 0.001). The overall radiographic density was higher in group ONE-C than in group TWO in the maxilla (p = 0.030). Conversely, in the mandible, these significant differences between the groups were not found (p > 0.05). Compared to the implants that survived, the implants that failed demonstrated a distinct radiographic density pattern (p < 0.05).

CONCLUSION

Within the limitations of the present study, the radiographic bone density in the maxilla appears to increase distinctly around short implants when cantilevers are used. In contrast, the radiographic density in the mandible appears to be unaffected by the use of a cantilever, suggesting a lower threshold of adaptation to occlusal forces and thus a higher susceptibility to overload and implant loss at earlier time points.

Effects of rmBMP-7 on Osteoblastic Cells Grown on a Nanostructured Titanium Surface

This study evaluates the effects of the availability of exogenous BMP-7 on osteoblastic cells’ differentiation on a nanotextured Ti surface obtained by chemical etching (Nano-Ti). The MC3T3-E1 and UMR-106 osteoblastic cell lines were cultured for 5 and 7 days, respectively, on a Nano-Ti surface and on a control surface (Control-Ti) in an osteogenic medium supplemented with either 40 or 200 ng/mL recombinant mouse (rm) BMP-7. The results showed that MC3T3-E1 cells exhibited distinct responsiveness when exposed to each of the two rmBMP-7 concentrations, irrespective of the surface. Even with 40 ng/mL rmBMP-7, important osteogenic effects were noticed for Control-Ti in terms of cell proliferation potential; Runx2, Osx, Alp, Bsp, Opn, and Smad1 mRNA expression; and in situ ALP activity. For Nano-Ti, the effects were limited to higher Alp, Bsp, and Opn mRNA expression and in situ ALP activity. On both surfaces, the osteogenic potential of UMR-106 cultures remained unaltered with 40 ng/mL rmBMP-7, but it was significantly reduced when the cultures were exposed to the 200 ng/mL concentration. The availability of rmBMP-7 to pre-osteoblastic cells at the concentrations used alters the expression profile of osteoblast markers, indicative of the acquisition of a more advanced stage of osteoblastic differentiation. This occurs less pronouncedly on the nanotextured Ti and without reflecting in higher mineralized matrix production by differentiated osteoblasts on both surfaces.

Dental Implant Failure Risk in Post Oncological Patients, a Retrospective Study and Sapienza Head and Neck Unit Decisional Protocol- 7 Years of Follow-Up

(1) Background: Patients with head and neck cancer are treated by ablative surgery, radiotherapy, chemotherapy, or a combination of these. The side effects of cancer therapies can compromise conventional prosthesis rehabilitation; therefore, dental implants can result in a more effective solution. The aim of the study is to explain how to rehabilitate a patient that underwent head and neck cancer therapy. (2) Methods: This retrospective study conducted from 2015 to 2021 included 223 postoncological patients, aged between 32 and 80 years old. Eighteen patients did not proceed with any treatment, and two died. Therefore, 203 patients have been analyzed and rehabilitated following our decisional protocol, with a mean period of follow-up of 4 years. The implant placement was considered successful when a mean bone loss of 1.6 mm for the first year and a mean of 0.13 mm in subsequent years occurred (3) Results: A total of 161 patients were rehabilitated with a conventional prosthesis, 42 patients (F:M ratio 19:23) with an implant-supported prosthesis and a total of 200 implants were placed; 9 implants were lost (4.5% of 200 implants). Conclusions: The results confirmed that by following our protocol it is possible to obtain an acceptable rate of implant survival, considering the delicacy and complexity of post-oncological patients.

Survival rate of dental implant placed using various maxillary sinus floor elevation techniques: A systematic review and meta-analysis

Aim

The aim of this systematic review is to evaluate the survival rate of dental implant placed using different maxillary sinus floor elevation techniques.

Setting and Design

PRISMA guidelines were used for this systematic review and meta-analysis.

Materials and Methods

Relevant articles were searched from Medline, PubMed, Google Scholar, ScienceDirect, and Cochrane trials. Articles published in English language were selected. Hand search was further conducted. For risk of bias, two tools were used, i.e., Cochrane tool for randomized controlled trials (RCTs) and new castle Ottawa quality assessment tool for non-RCTs.

Statistical Analysis

For statistical meta-analysis RevMan 5.4 software was used.

Results

Seventeen studies were finalized. All studies were included in the meta-analysis to check the implant survival rate. There is no statistical difference between direct and indirect techniques, and forest plot was derived for direct approach (P = 0.688, 95% confidence interval [CI] 0.9691) and for indirect approach (P = 0.686 and 95% CI 0.970).

Conclusion

There is no statistically significant difference in the survival rate of implant placed using direct or indirect sinus lift approach procedures. Hence, the technique is selected as per the indications given for each direct and indirect procedure.

Minimally Invasive Transcrestal Sinus Floor Elevation Procedure in Severely Atrophic Ridge: A Case Report

Typically, the greater the atrophy of the process, the more extensive and invasive the sinus floor elevation procedure is. This case of a 39-year-old man demonstrates a minimally invasive hydrostatic sinus lift from 1.7-mm height process in the site of lost tooth No. 16. Using a small flap, safe drills for a crestal approach diameter of 2.8 mm, 2 mL of saline solution under pressure of a syringe plunger, and 1 g of particulated bovine xenograft, a 14-mm height and 12-mm width sinus floor elevation was obtained. The implant was placed with a torque of 30 Ncm, and a healing cap was attached. Despite the very difficult conditions, the presented method not only resulted in a very good therapeutic effect but also reduced the number of procedures and time necessary for complete rehabilitation of the patient. The total treatment time to the final crown delivery was 6 months.

Different Treatment Modalities Using Dental Implants in the Posterior Maxilla: A Finite Element Analysis

The objective of this study was to compare the biomechanical behavior of peri-implant bone tissue and prosthetic components in two modalities of treatment for posterior region of the maxilla, using short implants or standard-length implants associated with bone graft in the maxillary sinus. Four 3D models of a crown supported by an implant fixed in the posterior maxilla were constructed. The type of implant: short implant (S) or standard-length implant with the presence of sinus graft (L) and type of crown retention: cemented (C) or screwed (S) were the study factors. The models were divided into SC- cemented crown on a short implant; SS- screwed crown on the short implant; LC- cemented crown on a standard-length implant after bone graft in the maxillary sinus and LS- crown screwed on a standard-length implant after bone graft in the maxillary sinus. An axial occlusal loading of 300 N was applied, divided into five points (60N each) corresponding to occlusal contact. The following analysis criteria were observed: Shear Stress, Maximum and Minimum Main Stress for bone tissue and von Mises Stress for the implant and prosthetic components. The use of standard-length implants reduced the shear stress in the cortical bone by 35.75% and the medullary bone by 51% when compared to short implants. The length of the implant did not affect the stress concentration in the crown, and the cement layer acted by reducing the stresses in the ceramic veneer and framework by 42%. Standard-implants associated with cemented crowns showed better biomechanical behavior.

Biomechanical comparison of implantation approaches for the treatment of mandibular total edentulism

Applying four anterior implants placed vertically or tilted in the mandible is considered to provide clinically reasonable results in the treatment of mandibular posterior edentulism. It is also reported that a combination of four anterior and two short posterior implants can be an alternative approach for the rehabilitation of severe atrophy cases. In this study, we aimed to evaluate the biomechanical responses of three different implant placement configurations, which represent the clinical options for the treatment of mandibular edentulism. Three-dimensional models of the mandible, prosthetic bar, dental implant, abutment, and screw were created. Finite element models of the three implant configurations (Protocol 1: Four anterior implants, Protocol 2: Four anterior and two short posterior implants, Protocol 3: Two anterior and two tilted posterior implants: All-on-4™ concept) were generated for 10 patients and analyzed under different loading conditions including chewing, biting, and impact forces. Protocol 2 led to the lowest stress concentrations over the mandible among the three protocols (p < 0.016). Protocol 2 resulted in significantly lower stresses than Protocol 3 and Protocol 1 over prosthetic bars under chewing forces (p < 0.016). None of the implant placement protocols consistently exhibited the lowest stress distribution over abutments. The lowest stresses over dental implants under the chewing, biting, and impact forces were obtained in Protocol 1, Protocol 2, and Protocol 3, respectively (p < 0.016). Protocol 3 was the best option to obtain the lowest stress values over the screws under all types of loading conditions (p < 0.016). In conclusion, Protocol 2 was biomechanically more ideal than Protocol 1 and Protocol 3 to manage the posterior edentulism.

Microbiological analysis of autologous bone particles obtained by low-speed drilling and treated with different decontamination agents

The aim of this study was to compare the effectiveness of three agents - two antibiotics (amoxicillin and clindamycin) and an antiseptic (chlorhexidine) - to decontaminate bone grafts obtained by low-speed drilling. The study included 248 bone tissue samples harvested from 62 patients by low-speed drilling before dental implant placement. Each of four samples obtained from every patient was dropped, using a sterile instrument, into a sterile tube containing a 500-μl solution of 400μg/mL amoxicillin, 150μg/mL clindamycin, 0.12% chlorhexidine, or physiological saline for 1min. The number of colony-forming units (CFU) was determined at 48h of culture. The use of clindamycin, amoxicillin, or chlorhexidine as decontaminant for 1min significantly reduced the CFU count when compared to physiological saline (control agent). In both anaerobic and CO₂-rich atmospheres, significant differences in CFU/mL were found between the control and chlorhexidine groups (P<0.001), control and amoxicillin groups (P<0.001), control and clindamycin groups (P<0.001), chlorhexidine and amoxicillin groups (P<0.0001), and chlorhexidine and clindamycin groups (P<0.0001). In conclusion, clindamycin had the highest decontaminating effect on bone particles obtained by low-speed drilling, followed by chlorhexidine and amoxicillin. Clindamycin may therefore be a valid alternative option for the routine decontamination of intraoral bone grafts.

Short Implants: An Answer to a Challenging Dilemma?

The purpose of this article is not to discuss the success of short dental implants versus standard/long dental implants, but to compare short dental implants with standard/long dental implants in areas that necessitated adjunctive bone grafting or augmentation procedures and as a way to avoid the need for advanced surgical procedures and their associated risks. It can be concluded that short dental implants are a viable alternative in sites that would have required additional complex and costly augmentation procedures. Short dental implants resulted in comparable survival and success rates with faster, less expensive treatment with fewer surgical complications and morbidity.

The effect of pulp inflammation and premature extraction of primary molars on the successor permanent teeth. A retrospective study

BACKGROUND

Untreated caries on primary molars often leads to pulp inflammation and extraction.

AIM

To retrospectively investigate the effect of pulp inflammation and extraction of primary molars on their successors regarding alignment in the dental arch and developmental enamel defects (DED).

DESIGN

The participants in this study were children at public schools in Petropolis (Brazil), who participated in a 3-year longitudinal clinical trial. Children (N = 44) were selected for the present study if they had at least one erupted premolar of which the predecessor primary molar presented pulp inflammation at baseline or during any of the 6-month follow-up assessments. All premolars were examined for DED and misalignment. Distinction was made between extraction performed before (E <8) or after the age of 8 years (E ≥8). Distinction was also made between pulp inflammation occurred before (P < 7) or after the age of 7 years (P ≥ 7). A logistic regression analysis was performed, and the odds ratio was calculated.

RESULTS AND CONCLUSIONS

Misalignment occurred more frequently in E <8 as compared to E ≥8 (OR = 2.85; P = .03). There was no significant difference in DED between P < 7 and P ≥ 7.

CONCLUSION

Misalignment of premolars occurs more frequently when the predecessor primary molars are extracted before the age of 8 years.

Effect of Smoking and Locations of Dental Implants on Peri-Implant Parameters: 3-Year Follow-Up

Background

Smoking may be a risk factor for marginal bone loss (MBL) and oral mucosal inflammation surrounding dental implants. This retrospective study evaluated the effects of smoking on dental implants in patients with fixed implant-supported prostheses over a period of 36 months following loading.

Material/Methods

We assessed 120 patients (68 women, 52 men, ages 19–74 years (mean age: 55.10 years) with 315 implants. Implants were classified according to location in the upper and lower jaws and anterior (placed between canines) or posterior (placed between pre-molars and molars) as follows: 1=maxilla anterior, 2=maxilla posterior, 3=mandible anterior, 4=mandible posterior. We also measured MBL, plaque index (PI), sulcus bleeding index (SBI), and probing depth (PD). P-values less than 0.05 were considered statistically significant.

Results

MBL was statistically greater in smokers (P<0.001) as compared to non-smokers in both jaws. MBL did not vary significantly by location in either group (smokers: p=0.415; non-smokers: p=0.175). Mean PI and PD scores were significantly higher in smokers as compared to non-smokers (P<0.001). A positive correlation was found between PI and PD scores in both groups. No statistically significant difference in SBI was observed between the 2 groups (P>0.05).

Conclusions

Smoking was associated with increases in marginal bone loss around implants, independent of their location in the jaws. Also, both plaque indices and probing depths were greater in smokers than in non-smokers.

A comparison of implant complications and failures between the maxilla and the mandible

STATEMENT OF PROBLEM

Identifying factors that affect the clinical outcomes of implant therapy is important.

PURPOSE

The purpose of this retrospective study was to determine whether implant location was a factor affecting the complication and failure rates of single-tooth implant-supported restorations in a predoctoral setting.

MATERIAL AND METHODS

The charts of 431 patients treated with a surgically placed dental implant and restored with a single crown in the predoctoral clinic were analyzed. Data on implant location, type of complication (surgical or prosthetic), and type of failure were collected and analyzed according to implant location using the Fisher Exact Test and Mantel-Haenszel Exact Chi Square Test analysis (α=.05).

RESULTS

The charts revealed 158 complications (68 surgical and 90 prosthetic) in 110 patients, and 3.9% of the implants failed. No statistically significant difference was found between the number of surgical complications or prosthetic complications in the maxilla and the mandible (P=.469).

CONCLUSIONS

Jaw location (maxilla compared with mandible) of the implant had no statistically significant impact on the incidence of surgically or prosthetically related complications. No statistically significant difference was found in overall implant failures, surgical failures, and prosthetic failures between maxillary and mandibular implants.

One-stage laser-microtextured implants immediately placed in the inter-radicular septum of molar fresh extraction sockets associated with GBR technique. A case series study

Background

The outcome of one-stage trans-mucosal immediate implants with simultaneous guided bone regeneration (GBR) technique has become highly predictable. Furthermore, when this approach is performed to place one-stage implants into the inter-radicular septum of fresh extraction sockets in the molar region, the risk of incorrect emergence profile and off-angle loading is reduced. The aim of the present study was to clinically evaluate the horizontal hard and soft tissue changes, and radiographically the vertical socket walls remodeling, and the early peri-implant marginal bone loss (EMBL) following the placement of immediate one-stage implants in the inter-radicular septum of molar fresh extraction sockets, associated with a collagen membrane.

Material and Methods

Twenty patients were selected to receive a one-stage implant with laser-microtextured collar surface into the inter-radicular septum of a fresh molar extraction sockets, associated with a simultaneous placement of a collagen membrane. Intraoral radiographs and model casts were used for the evaluation. Correlation between the amount of the keratinized tissue thickness (KTT) with EMBL was also analyzed.

Results

After 4 months, the vertical radiographic mesial and distal EMBL around implants was of 0.06 ±0.01 mm and 0.04±0.02 mm, respectively, with no statistically significant difference between T0 and T1 (P >0.05). No statistical differences were found also for each radiographic measure used for the examination of implant sites vertical bone changes (p >0.05). Clinically, horizontal changes of the bucco-lingual central width were found statistically significant (p<0.05), whereas no statistical differences were found for bucco-lingual mesial and distal width changes (p >0.05). In addition, no statistically significant correlation between EMBL and the amount of KTT was found (P >0.05).

Conclusions

Results suggest that the immediate placement of one-stage laser-microtextured implants could provide advantages in preserving the extraction socket's hard and soft tissue remodeling, and the peri-implant marginal bone level before the prosthetic loading. Key words:One-stage implant, laser-microtextured collar surface, GBR, collagen membrane.

Impact of jaw location on clinical and radiological status of dental implants placed in cigarette-smokers and never-smokers: 5-year follow-up results

PURPOSE

The aim of this 60 months follow-up investigation was to investigate the impact of jaw location on clinical and radiological status of dental-implant therapy in cigarette-smokers and never-smokers.

MATERIALS AND METHODS

Twenty-nine self-reported cigarette-smokers and 27 nonsmokers were assessed. All implants were categorized into three regions with reference to their location in the maxilla or mandible: (a) Anterior zone: implants located in anterior teeth; (b) Middle zone: Implants located in the premolar region; and (c) posterior zone: implants located in the molar region. Peri-implant crestal bone loss (CBL), bleeding-on-probing (BOP) and probing-depth (PD) ≥ 4 mm and were assessed. Level of statistical significance was set at P < .05.

RESULTS

Mean age of cigarette-smokers (n = 29) and never-smokers (n = 27) was 44.5 years (39-51 years) and 43.6 years (35-49 years), respectively. The average duration of cigarette-smoking was 20.3 years (17-26 years). The mean periimplant PD (P < .05) and CBL (P < .05) were significantly higher in cigarette-smokers in contrast to never-smokers in all zones. No statistically significant differences in CBL, PD, and BOP were observed in the three zones of implant location among cigarette-smokers and never-smokers.

CONCLUSION

Smoking enhanced PD and CBL around dental implants and this relationship was independent of site of implant placement and jaw location.

Nicotine, the Predictor of Success or Failure of Dental Implants: A Retrospective Study

Background:

Dental implant therapy is a treatment of choice in missing teeth. However, certain conditions such as smoking, hypertension, and diabetes have negative influence on success of dental implants. Nicotine is found to cause osteoclastic changes. The present study was conducted to assess the relationship between nicotine and implant failure.

Materials and Methods:

The present retrospective study included 2570 patients of both genders. They were divided into two groups. Group I consisted of 1250 patients with a history of smoking and Group II were nonsmokers and comprised 1320 patients. The presence of pain, mobility, and inflammation was considered positive signs for implant failure.

Results:

The results showed that in Group I, males had 6.13% and females had 5% dental implant failure. Overall failure rate in Group I was 5.56%. In Group II, males had 2.98% and females had 0.9% failure. Overall failure rate in Group II was 2.35%. The difference between both groups was statistically significant (P < 0.05). In Group I, maximum (56), and in Group II, 18 patients had habit of >10 years of smoking. Maximum patients had habit of consumption of >20 cigarettes/day (Group I) and Group II had only 10 patients with this frequency. Maximum dental implant failures were observed in maxillary arch (70) than in mandibular arch (32). The difference was statistically significant (P < 0.05).

Conclusion:

Smoking influences the survival rate of dental implants. Thus, patient should be educated to discontinue the habit before implant placement.

Er:YAG laser, piezosurgery, and surgical drill for bone decortication during orthodontic mini-implant insertion: primary stability analysis-an animal study

It is important to identify factors that affect primary stability of orthodontic mini-implants because it determines the success of treatment. We assessed mini-implant primary stability (initial mechanical engagement with the bone) placed in pig jaws. We also assessed mini-implant insertion failure rate (mini-implant fracture, mini-implants to root contact). A total of 80 taper-shaped mini-implants (Absoanchor® Model SH1312-6; Dentos Inc., Daegu, Korea) 6 mm long with a diameter of 1.1 mm were used. Bone decortication was made before mini-implant insertion by means of three different methods: Group G1: Er:YAG laser (LiteTouch®, Light Instruments, Yokneam, Israel) at energy of 300 mJ, frequency 25 Hz, fluence 38.2 J/cm2, cooling 14 ml/min, tip 1.0 × 17 mm, distance 1 mm, time of irradiation 6 s; Group G2: drill (Hager & Meisinger GmbH, Hansemannstr, Germany); Group G3: piezosurgery (Piezotom Solo, Acteon, NJ, USA). In G4 group (control), mini-implants were driven by a self-drilling method. The primary stability of mini-implants was assessed by measuring damping characteristics between the implant and the tapping head of Periotest device (Gulden-Medizinteknik, Eschenweg, Modautal, Germany). The results in range between − 8 to + 9 allowed immediate loading. Significantly lower Periotest value was found in the control group (mean 0.59 ± 1.57, 95% CI 0.7, 2.4) as compared with Er:YAG laser (mean 4.44 ± 1.64, 95% CI 3.6, 5.3), piezosurgery (mean 17.92 ± 2.73, 95% CI 16.5, 19.3), and a drill (mean 5.91 ± 1.52, 95% CI 5.2, 6.6) (p < 0.05). The highest failure rate (33.3%) during mini-implant insertion was noted for self-drilling method (G4) as compared with G1, G2, and G3 groups (p < 0.05). The small diameter decortication by Er:YAG laser appeared to provide better primary stability as compared to drill and piezosurgery. Decortication of the cortical bone before mini-implant insertion resulted in reduced risk of implant fracture or injury of adjacent teeth. The high initial stability with a smaller diameter of the mini-implant resulted in increased risk of fracture, especially for a self-drilling method.

Comparison of Clinical, Radiographic, and Immunologic Inflammatory Parameters around Crestally and Subcrestally Placed Dental Implants: 5-Year Retrospective Results

PURPOSE

To compare changes in clinical (bleeding on probing [BOP] and probing pocket depth [PPD]), radiographic (crestal bone loss [CBL]), and immunologic inflammatory (interleukin-1beta [IL-1β] and matrix metalloproteinase-9 [MMP-9]) parameters around crestally and subcrestally placed dental implants 5 years after implant placement.

MATERIALS AND METHODS

Fifty-two patients were divided into 2 groups: group 1 (n = 27): patients with single implants placed approximately 2 mm below the alveolar crest; group 2 (n = 25): patients with single implants placed at bone level. In both groups, peri-implant BOP, PPD, and CBL were measured, and levels of IL-1β and MMP-9 were determined in duplicates using enzyme-linked immunosorbent assay. Full-mouth debridement was performed biannually in both groups. Statistical analysis was performed using the Mann-Whitney U test (significance set at p < 0.05).

RESULTS

All measurements in groups 1 and 2 were performed 5.3 ± 0.2 and 5.2 ± 0.1 years after implant placement, respectively. The mean CBL was 1.2 ± 0.2 mm and 1.4 ± 0.2 mm in groups 1 and 2, respectively. There was no significant difference in mean BOP, PPD, CBL and in levels of IL-1β, and MMP-9 among implants in both groups.

CONCLUSION

Clinical, radiographic, and immunologic inflammatory parameters are comparable around crestally and subcrestally placed single dental implants up to 5 years after placement. The depth of implant placement appears to have no effect on clinical status and performance of single dental implants.

Cumulative survival rate and associated risk factors of Implantium implants: A 10-year retrospective clinical study

PURPOSE

The objective of this study was to determine the cumulative survival rate (CSR) and associated risk factors of Implantium implants by retrospective clinical study.

MATERIALS AND METHODS

Patients who received Implantium implants (Dentium Co., Seoul, Korea) at Korea University Guro Hospital from 2004 to 2011 were included. The period between the first surgery and the last hospital visit until December 2015 was set as the observation period for this study. Clinical and radiographic data were collected from patient records, including all complications observed during the follow-up period. Kaplan-Meier analysis was performed to examine CSR. Multiple Cox proportional hazard model was employed to assess the associations between potential risk factors and CSR.

RESULTS

A total of 370 implants were placed in 121 patients (mean age, 56.1 years; range, 19 to 75 years). Of the 370 implants, 13 failed, including 7 implants that were lost before loading. The 10-year cumulative survival rate of implants was 94.8%. The multiple Cox proportional hazard model revealed that significant risk factor of implant failure were smoking and maxillary implant (P<.05).

CONCLUSION

The 10-year CSR of Implantium implants was 94.8%. Risk factors of implant failure were smoking and maxillary implant.

Influence of implant location in patients with and without type 2 diabetes mellitus: 2-year follow-up

The aim of the present cross-sectional retrospective 2-year follow-up clinical study was to assess the influence of implant location on clinical and radiographic parameters around dental implants placed in patients with and without type 2 diabetes mellitus (T2DM). Twenty-seven patients with T2DM and 25 non-diabetic controls were included. Implants were classified into three zones according to their location: (1) anterior zone: implant/s replacing anterior teeth, (2) middle zone: implant/s replacing premolars, and (3) posterior zone: implant/s replacing molars. Peri-implant bleeding on probing (BOP), probing depth (PD), and crestal bone loss (CBL) were measured. P-values less than 0.05 were considered statistically significant. The mean age of patients with T2DM was 42.5 years and that of non-diabetic controls was 40.6 years. The mean fasting blood glucose levels of patients with and without T2DM were 74.5mg/dl (66-80mg/dl) and 82.5mg/dl (79-88.1mg/dl), respectively. The mean duration of T2DM was 4.3 years. There was no significant difference in BOP, PD, or CBL around implants placed in any of the zones in the jaws of patients with and without T2DM. There is no influence of implant location on clinical and radiographic parameters around dental implants placed in patients with and without T2DM.

A Retrospective Survival Study of Trabecular Tantalum Implants Immediately Placed in Posterior Extraction Sockets Using a Flapless Technique

A retrospective review of patient records was conducted in a single private practice to evaluate the efficacy of immediately placing a novel implant design in posterior jaw locations using a flapless technique. Forty-two patients (22 males, 20 females) with a mean (SD) age of 60.2 (7.6) years (range = 31-68) presented with 1-2 nonrestorable molar (maxillary = 14; mandibular = 8) or premolar (maxillary = 20; mandibular = 1) teeth compromised by periodontal disease, endodontic failure, root resorption, root fracture, or severe caries. Most patients (78.6%) had moderate (66.7%) or severe (11.9%) periodontitis. Other comorbidities included smoking (14.3%) and controlled diabetes mellitus (11.9%). After atraumatic extraction, teeth were immediately replaced with a total of 44 trabecular tantalum implants (Trabecular Metal Implants, Zimmer Biomet Dental) (diameter = 3.7-4.7 mm; length = 10-13 mm). Sites requiring augmentation were treated with 3 types of small-particle (250-1000 μm), mineralized, solvent-dehydrated, allografts (Puros) based on location: cortical for crestal sinus grafts, cancellous for peri-implant voids in thick tissue biotypes, or cortical-cancellous (70:30) mix for peri-implant voids in thin tissue biotypes. Cortical particulate was used when slower resorption would help maintain graft volume for esthetics or implant support. Grafts were covered with resorbable bovine pericardium membranes (CopiOs, Zimmer Biomet). Cumulative implant survival and success rates were 97.7%, respectively, with a mean (±SD) follow-up time of 25.0 ± 12.1 months (range = 4-48). One asymptomatic implant failed to osseointegrate. Within the limitations of this study, implants achieved outcomes comparable to conventionally placed and restored single-tooth implants in anterior jaw locations.

Retrospective clinical study of ultrawide implants more than 6 mm in diameter

Background

The prognosis of wide implants tends to be controversial. While wider implants were initially expected to result in a larger osseointegration area and have higher levels of primary stability, they were reported to have a relatively high rate of failure. The clinical outcome of ultrawide implants of more than 6 mm in diameter was evaluated through a retrospective study.

Methods

The investigation was conducted on patients who had received ultrawide implant (≥6 mm diameter) placements in Seoul National University Bundang Hospital from January 2008 to December 2013. Complications were investigated during the maintenance period, and marginal bone loss was measured using periapical radiography. Primary stability immediately after the implant placement and second stability after second surgery or during impression were measured using Osstell^® Mentor (Osstell, Sweden) as an implant stability quotient (ISQ).

Results

Fifty-eight implants were placed in 53 patients (30 male, 23 female), and they were observed for an average of 50.06 ± 23.49 months. The average ISQ value increased from 71.22 ± 10.26 to 77.48 ± 8.98 (P < 0.005). The primary and secondary stability shows significantly higher at the mandible than at the maxilla (P < 0.001). However, mean survival rate shows 98.28 %. Average marginal bone loss of 0.018 and 0.045 mm were measured at 12 and 24 months after the loading and 0.14 mm at final follow-up date (mean 46.25 months), respectively. Also in this study, the bone loss amount was noticeably small compared to regular implants reported in previous studies.

Conclusions

The excellent clinical outcome of ultrawide implants was confirmed. It was determined that an ultrawide implant can be used as an alternative when the bone quality in the posterior teeth is relatively low or when a previous implant has failed.

Two anterior wide-diameter implants using the All-on-4 concept in a predictable maxillary rehabilitation: A clinical report

The quality of maxillary bone is generally lower than that of mandibular bone; consequently, complete arch immediate implant-loading treatment is not as predictable in the maxillary as in the mandibular arch. The All-on-4 concept has proven to be an effective and successful treatment protocol. However, the survival rate of All-on-4 implants in the maxilla is lower than of those in the mandible. In this report, 2 anterior wide-diameter implants were used with the All-on-4 concept for a maxillary rehabilitation to provide biomechanical benefits with better primary stability while still achieving a functional and esthetic result. The clinical challenges of using wide-diameter implants in the anterior region are also discussed and should be considered during treatment planning.

Survival analysis of wide dental implant: systematic review and meta-analysis

OBJECTIVE

Wide-diameter implants are frequently placed in molar sites to obtain appropriate restoration profiles, to rescue implants that lack stability, and to engage bone in extraction sites. However, studies of wide-diameter implant placement have provided conflicting evidence regarding clinical outcomes. This systematic review aims to analyze survival rates of wide-diameter implants (platform diameter ≥5 mm) and assess clinical variables potentially affecting failure rates.

MATERIAL AND METHODS

Electronic search was conducted using MEDLINE (PubMed), Cochrane Central Register of Controlled Trials (CENTRAL) and EMBASE from January 1980 to October 2014. Publication screening, data extraction, and quality assessment were performed. Failure rate per implant-year was analyzed using mix-effects Poisson regression model to obtain summary estimates of the 5-year survival rate. Relative risk (RR) was calculated to evaluate the association of different clinical variables with estimated failure rates.

RESULTS

Eleven retrospective studies and eight prospective studies having at least 1-year follow-up period were included in the analysis. The estimated 5-year survival rate was 92.67% (95% confidence interval: [79.60, 97.50]) in the retrospective studies and 97.76% (Confidence interval: [93.25, 99.27]) in the prospective studies. Implant surface and implant diameter were significantly associated with the failure events in the retrospective studies.

CONCLUSIONS

Placement of wide-diameter implants demonstrated a promising survival rate during 5-year follow-up. Further controlled trials with the control group and longer follow-up period are needed to provide the direct evidence comparing survival rates of wide implants with survival rates of narrower implants.

A Comparative Study of Stability After the Installation of 2 Different Surface Types of Implants in the Maxillae of Dogs

PURPOSE

This study was performed to investigate the histologic and histomorphometric findings of 2 different types of implant.

MATERIALS AND METHODS

Resorbable blasting media (RBM) and sandblasted with larger grit and acid etched (SLA) surfaced implants (24 fixtures in each group) were installed in posterior maxilla of dogs. The initial stability was measured using Periotest (Periotest value [PTV]). After 6 or 12 weeks, fixtures with surrounding bone were harvested.

RESULTS

The average initial stability of the SLA group (-1.71 ± 2.9) was higher than that of the RBM group (-1.25 ± 3.21), but there was no significant difference. The mean PTV of the RBM surface was higher than the SLA surface at 12 weeks. The average bone-implant contacts were 67.6% ± 16.0% at 6 weeks and 82.7% ± 8.6% at 12 weeks in the SLA group and 69.9% ± 17.6% at 6 weeks and 78.3% ± 9.2% at 12 weeks in the RBM group.

CONCLUSION

The SLA and resorbable blasting media (RBM) surface implants demonstrated good stabilities and healing processes of the surrounding bone in the posterior maxilla. Therefore, the two domestic implants could provide predictable clinical results.

Modified osteotome sinus floor elevation using combination platelet rich fibrin, bone graft materials, and immediate implant placement in the posterior maxilla

The osteotome technique is more predictable with simultaneous implant placement when there is <5-7 mm of preexisting alveolar bone height beneath sinus. Proper combination of platelet rich fibrin, mineralized freeze-dried human bone allograft, and autogenous bone has been recommended for this situation. The purpose of this article was to describe the proper method and materials which can grow >10 mm bone with osteotome technique and grafting materials where the edentulous posterior maxilla radio-graphically showed less bone between the alveolar crest and sinus floor.

Three-dimensional evaluation of human jaw bone microarchitecture: correlation between the microarchitectural parameters of cone beam computed tomography and micro-computer tomography

OBJECTIVE

To evaluate the potential feasibility of cone beam computed tomography (CBCT) in the assessment of trabecular bone microarchitecture.

STUDY DESIGN

Sixty-eight specimens from four pairs of human jaw were scanned using both micro-computed tomography (micro-CT) of 19.37-μm voxel size and CBCT of 100-μm voxel size. The correlation of 3-dimensional parameters between CBCT and micro-CT was evaluated.

RESULTS

All parameters, except bone-specific surface and trabecular thickness, showed linear correlations between the 2 imaging modalities (P < .05). Among the parameters, bone volume, percent bone volume, trabecular separation, and degree of anisotropy (DA) of CBCT images showed strong correlations with those of micro-CT images. DA showed the strongest correlation (r = 0.693).

CONCLUSIONS

Most microarchitectural parameters from CBCT were correlated with those from micro-CT. Some microarchitectural parameters, especially DA, could be used as strong predictors of bone quality in the human jaw.

Osseoconductivity of a Specific Streptavidin-Biotin-Fibronectin Surface Coating of Biotinylated Titanium Implants - A Rabbit Animal Study

BACKGROUND

Biofunctionalized implant surfaces may accelerate bony integration and increase long-term stability.

PURPOSE

The aim of the study was to evaluate the osseous reaction toward biomimetic titanium implants surfaces coated with quasicovalent immobilized fibronectin in an in vivo animal model.

MATERIALS AND METHODS

A total of 84 implants (uncoated [control 1, n = 36], streptavidin-biotin coated [test 1, n = 24], streptavidin-biotin-fibronectin coated [test 2, n = 24]) were inserted 1 mm supracortically in the proximal tibia of 12 rabbits. The samples were examined after 3 and 6 weeks. Total bone-implant contact (tBIC; %), bone-implant contact in the cortical (cBIC; %) and in the spongious bone (sBIC; %) as well as the percentage of linear bone fill (PLF; %) were evaluated.

RESULTS

After 3 weeks, streptavidin-biotin-fibronectin implants had a significant higher sBIC (p = .043) and PLF (p = .007) compared with the uncoated samples. After 6 weeks, this difference was significant for tBIC (p = .016) and cBIC (p < .001). Additionally, uncoated screws showed a significant higher sBIC when compared with the fibronectin coating (p < .001). Streptavidin-biotin-coated implants showed less bone growth at both time points of all examined parameters when compared with their counterparts (all p < .001).

CONCLUSIONS

Quasicovalent immobilization of biotinylated fibronectin with the streptavidin-biotin-fibronectin system on smooth surface titanium shows a beneficial faster osseous healing in vivo. Besides, an antifouling effect of the streptavidin-biotin coating was proven.

The Influence of Tactile Perception on Classification of Bone Tissue at Dental Implant Insertion

BACKGROUND

Various ways of using the Lekholm and Zarb (L&Z) classification have added to the lack of scientific evidence of the effectiveness of this clinical method in the evaluation of implant treatment.

PURPOSE

The study aims to assess subjective jawbone classifications in patients referred for implant treatment, using L&Z classification with and without surgeon's hand perception at implant insertion. The association between bone type classifications and quantitative parameters of primary implant stability was also assessed.

MATERIALS AND METHODS

One hundred thirty-five implants were inserted using conventional loading protocol. Three surgeons classified bone quality at implant sites using two methods: one based on periapical and panoramic images (modified L&Z) and one based on the same images associated with the surgeon's tactile perception during drilling (original L&Z). Peak insertion torque and implant stability quotient (ISQ) were recorded.

RESULTS

The modified and original L&Z were strongly correlated (rho = 0.79; p < .001); Wilcoxon signed-rank test showed no significant difference in the distribution of bone type classification between pairs using the two methods (p = .538). Spearman correlation tested the association between primary stability parameters and bone type classifications (-0.34 to -0.57 [p < .001]).

CONCLUSIONS

Tactile surgical perception has a minor influence on rating of subjective bone type for dental implant treatment using the L&Z classification.

A comparison of mandibular and maxillary alveolar osteogenesis over six weeks: a radiological examination

INTRODUCTION

Insufficient information exists on comparing radiological differences in bone density of the regeneration rate in the alveolar bone of the maxilla and mandible following the creation of similar defects in both.

METHODS

Alveolar bone defects were created from five healthy Chacma baboons. Standardized x-ray images were acquired over time and the densities of the selected defect areas were measured pre-operatively, directly post-operatively and at three- and six weeks post-operatively. Differences in densities were statistically tested using ANOVA.

RESULTS

The maxilla was significantly more radiologically dense (p = 0.026) than the mandible pre- operatively. No differences were obtained between the maxilla and mandible directly postoperatively and three- and six weeks post-operatively respectively; i.e. densities were not significantly different at the different time points after the defects had been created (three weeks: t = 1.08, p = 0.30; six weeks: t = 1.35, p = 0.19; three to six weeks: t = 1.20, p =0.25). The increase in density in the mandible was 106% (8.9 ± 7.6%/time versus 4.3 ± 2.7%/time) over three weeks, 28% (15.0 ± 8.1%/time versus 11.7 ± 8.0%/time) over six weeks and 56% (12.5 ± 9.7%/time versus 8.0 ± 6.9%/time) over three-to-six weeks and was higher than in the maxilla over the same intervals.

CONCLUSIONS

Radiological examination with its standardized gray-scale analysis can be used to determine the difference in bone density of the maxilla and mandible. Although not statistically significant, the mandible healed at a faster rate than the maxilla, especially observed during the first three weeks after the defects were created.

Nasal Floor Elevation for Implant Treatment in the Atrophic Premaxilla: A Within-Patient Comparative Study

BACKGROUND

There is a lack of evidence regarding success of implants placed in atrophic premaxilla using the nasal floor elevation technique.

PURPOSE

This study aimed to compare implants placed in augmented bone in the anterior maxilla using the nasal floor elevation technique with implants placed in the maxillary sinus region using the sinus lift technique.

MATERIALS AND METHODS

A within-patient controlled clinical trial was performed on 14 patients receiving 78 implants. The implants were assigned to one of two study groups on the basis of implant location. A total of 37 implants were placed in the nasal fossa region (NF group), and 41 implants were placed in the maxillary sinus region (MS group). Patients were followed up for 4.5 ± 2.2 years, with comparable follow-up times for implants in NF and MS groups (4.7 ± 2.1 and 4.9 ± 2.1 years, respectively; p > .05). Treatment outcomes were assessed and statistically analyzed.

RESULTS

Implant success rate was 89.2% in the NF group and 95.0% in the MS group, with no statistically significant difference between them (p > .05). No nasal or sinus membrane perforation or other complications were reported within the follow-up period. Significant differences were found between the two groups in terms of residual bone height, augmented bone height, and implant diameter.

CONCLUSIONS

Nasal floor elevation is an effective and safe procedure that can be used for implant placement in atrophic premaxilla with success rates that are comparable to those of implants placed in the maxillary sinus.

Should oral implants be splinted in a mandibular implant-supported fixed complete denture? A 3-dimensional-model finite element analysis

STATEMENT OF PROBLEM

The design of a mandibular fixed complete denture can influence periimplant bone loss. However, the design that transfers the greatest stress to the periimplant bone is not well documented.

PURPOSE

The purpose of this study was to assess the stress distribution associated with splinted and nonsplinted implant-supported mandibular fixed complete denture designs.

MATERIAL AND METHODS

Three-dimensional finite element models simulating 6 osseointegrated implants were created in the mandible to support a cobalt-chromium alloy and feldspathic porcelain veneering framework. One model simulated a 1-piece framework, and the other models simulated 2-piece and 3-piece frameworks. Axial and oblique loads were applied to the frameworks.

RESULTS

For all the models, the greatest stress values were recorded in the periimplant bone of posterior implants, with differences between the left and right sides. The axial load transferred greater stress values to the periimplant bone than did the oblique load. The lowest periimplant bone stress values were observed in the 3-piece framework model at all implant locations, with the exception of implants placed in the canine region.

CONCLUSIONS

A framework separated into 3 pieces transfers the least stress to the periimplant bone.

Accuracy of Quantitative Computed Tomography Bone Mineral Density Measurements in Mandibles: A Cadaveric Study

PURPOSE

The aim was to investigate the accuracy of quantitative computed tomography bone mineral density (BMD) measurements in mandibles, comparing measured BMD with calibrated BMD.

MATERIALS AND METHODS

Seventy mandibles from adult cadavers were used. Twenty tomographic cuts were made in each mandible. In each tomographic cut, a region of interest was located, and the bone density was measured in Hounsfield unit (HU). A polymethyl methacrylate phantom containing four inserts of different predetermined densities (hydroxyapatite 100, 200, 500, and 700 mg/cm(3) ) was used to calculate calibrated bone density. Correlation between measured and calibrated bone densities was calculated.

RESULTS

Mean total correlation between measured and calibrated BMD in the 20 sagittal tomography cuts showed almost perfect positive correlation (r = 0.998, p < .001). However, when average BMD measurements in HU were compared, the measured total BMD (in the 20 sagittal tomography cuts studied) was 54.99 ± 421.59, whereas the total calibrated BMD was 49.28 ± 364.95, with statistically significant difference (p = .001).

CONCLUSIONS

There are discrepancies between measured and calibrated BMD; in this sense, a calibrated bone phantom with a predetermined mineral density should be used to determine the exact BMD before dental implants surgery.

Three-dimensional finite element analysis of implant-supported crown in fibula bone model

PURPOSE

The purpose of this study was to compare stress distributions of implant-supported crown placed in fibula bone model with those in intact mandible model using three-dimensional finite element analysis.

MATERIALS AND METHODS

Two three-dimensional finite element models were created to analyze biomechanical behaviors of implant-supported crowns placed in intact mandible and fibula model. The finite element models were generated from patient's computed tomography data. The model for grafted fibula was composed of fibula block, dental implant system, and implant-supported crown. In the mandible model, same components with identical geometries with the fibula model were used except that the mandible replaced the fibula. Vertical and oblique loadings were applied on the crowns. The highest von Mises stresses were investigated and stress distributions of the two models were analyzed.

RESULTS

Overall stress distributions in the two models were similar. The highest von Mises stress values were higher in the mandible model than in the fibula model. In the individual prosthodontic components there was no prominent difference between models. The stress concentrations occurred in cortical bones in both models and the effect of bicortical anchorage could be found in the fibula model.

CONCLUSION

Using finite element analysis it was shown that the implant-supported crown placed in free fibula graft might function successfully in terms of biomechanical behavior.

Sinus augmentation via transcrestal approach: a comparison between the balloon and osteotome technique in a cadaver study

BACKGROUND

The transcrestal approach with osteotomes is a commonly applied and predictable technique for maxillary sinus floor elevation. However, Schneiderian membrane perforation is a common and often inevitable intraoperative complication. Recently, the use of balloons has been proposed to reduce the risk of sinus membrane perforation and to facilitate the surgical technique. The aim of this study was to determine membrane elevation height and perforation rate using the transcrestal balloon technique (B) and a conventional osteotome approach, as control (C).

METHODS

Ten fresh, completely edentulous cadaver heads (seven male and three female) were selected. In a split-mouth design, each sinus was randomly assigned to either the experimental or the control technique. Pre-surgical planning was aided by cone-beam computed tomography. During the procedure, an endoscope was used to monitor the elevation procedure and the occurrence of sinus perforation. The elevation continued until either 15 mm (measured from the alveolar crest) was reached or a perforation occurred. The residual ridge and the elevated membrane height were measured and compared with the paired Student's t-test. Presence of sinus perforation was recorded at three cutoff points: 10, 12, and 15 mm.

RESULTS

The mean age of the specimens was 77.7 ± 14.2 years (range 49-92). The mean initial, final, and elevated sinus membrane height for the B group was 5.3 ± 1.9, 13.7 ± 1.9, and 8.3 ± 3.1 mm, whereas the correspondent values for the C group were 5.1 ± 2.1, 13.2 ± 2.8, and 8.1 ± 3.1 mm. The incidence of sinus perforation, using 10, 12, and 15 mm as end points was 0%, 22.2%, and 44.4% in the B group, whereas in the C group the respective values were 10.0%, 20.0%, and 50.0%. No statistically significant differences were found between the two groups for all the above-mentioned variables. In addition, mean residual ridge height was not significantly different between the non-perforation and perforation sites in the B group (5.2 ± 2.2 and 5.5 ± 1.7 mm) and in the C group (5.2 ± 2.5 and 5.0 ± 2.0 mm). Three cadavers had perforations in both sinuses, accounting for 66.6% of total number of perforations.

CONCLUSIONS

Based on the findings of this study, the balloon and the conventional osteotome approach are comparable in terms of perforation rate as it relates to the elevation height. Also, the amount of residual alveolar bone was not related to the incidence of perforation and the height of sinus elevation.

Piezosurgery-assisted, flapless split crest surgery for implant site preparation

INTRODUCTION

Bucco-lingual resorption of the alveolar ridge can, at times, be predictably corrected at the time of implant placement. Among the different options available to achieve this are a group of surgical techniques described as split crest or split ridge procedures. Most of these procedures require the use of a mallet and some type of chisels and/or osteotomes; they are very technique-sensitive and can be uncomfortable for patients. Recently, alternative tools to split the crest have been presented, and these include the newer bone expanders and the piezoelectric scalpel. A flapless approach to implant dentistry has become popular with the aim to alleviate post treatment side effects, accelerate healing and avoid bone resorption caused by flap elevation.

METHODS

We present a technique combining the use of a piezoelectric scalpel and a tapered bone expander in a flapless fashion as a novel way to perform split crest procedures with an aim to optimize outcomes and acceptability by patients.

RESULTS

All implants were successfully placed and the resorbed ridge expanded in the same setting. Findings were confirmed by postoperative cone beam cat scan (CBCT) evaluation.

CONCLUSIONS

This new technique is a predictable approach for split crest procedures and has high acceptability by patients and is technically simple for surgeons.

Postextraction osteotome sinus floor elevation technique using plasma-rich growth factors

PURPOSE

To evaluate a modified osteotome sinus floor elevation technique with immediate postextraction implant placement and the adjunct of a platelet-derived fibrin plug for the rehabilitation of maxillary premolar sites.

MATERIAL AND METHODS

Fifteen patients with nonrestorable fractured endodontically treated maxillary premolars were consecutively enrolled in the study. After extraction, the membrane was gradually elevated using osteotomes, with the interposition of a fibrin clot. Subsequently, an implant embedded with plasma very rich in growth factors was inserted.

RESULTS

No implant failed after a mean follow-up of 35 months. The average membrane lift was 2.9 ± 0.8 mm. After 1 year of loading, marginal bone loss averaged 0.36 ± 0.19 mm. No postoperative symptoms were reported. All patients reported full satisfaction for mastication function, phonetics, and aesthetics.

CONCLUSIONS

The present technique represents a viable option for the rehabilitation of fresh postextraction maxillary premolar sockets.