Surgical protocols for early implant placement in post-extraction sockets: a systematic review

Achieving Predictable Esthetics With Early Implant Placement and Soft Tissue Modeling: A Case Report and Literature Review

In the modern era, patients are increasingly concerned about dental esthetics. Edentulism can significantly impact the appearance, occlusion, and self-esteem of the patient. Treatment options like removable dentures, fixed crown and bridge prostheses, and resin-retained bridges are available to replace missing teeth. Implant therapy is popular due to its high success rates and long-term durability. However, its efficacy can be compromised by errors in treatment planning, surgery, tissue care, and infections. Thus, meticulous planning and execution are crucial. Clinicians must have the expertise to manage difficulties during surgery and maintain stable soft tissue. The stability of tissues around osseointegrated implants affects long-term clinical stability and esthetics. Early implant placement is recommended for missing teeth in the esthetic zone, aiming to place implants in anatomically and functionally correct positions for durable and esthetic results. Patients with high cosmetic demands, thin gingival biotypes, and high smile lines pose challenges. Assessing Pink and White esthetics guides treatment planning. Advantages of early implant placement include simplified procedures and reduced post-surgical complications. Soft tissue molding is achieved using customized healing abutments and temporizing with fiber-reinforced resin-bonded prostheses. Customized healing abutments preserve socket width, prevent soft tissue collapse, and promote natural contouring, eliminating the need for secondary surgeries and aiding spontaneous healing. This case report outlines a comprehensive approach to achieving predictable esthetics through early implant placement and soft tissue modeling in a patient with a traumatically avulsed maxillary central incisor.

Early Implant Placement with Immediate Loading in the Mandibular Anterior Region: A Rapid Solution to Edentulism

The aim of this article is to present the case of an early implant placement with immediate loading in the mandibular anterior region as a rapid solution to edentulism. A 40-year-old healthy male patient reported with a chief complaint of loosening of tooth in the lower front region of the jaw. On intraoral examination, there was a mobile tooth with respect to 41. The mobile tooth was extracted, and early implant placement was done along with Bio-Oss bone grafts to fill the jumping distance with no barrier membrane. Immediate provisionalisation was done on early-placed dental implants. After 5 months of the healing period, the final implant-level impressions were made, and the provisional crown was replaced with the final zirconia crown. This case report demonstrates satisfactory esthetic and functional outcomes along with various other advantages.

Early Implant Bone Loss in the Preprosthetic Phase: A Retrospective Study

Initiation of the inflammatory response begins with the surgical placement of an implant that stimulates bone remodeling. The occurrence of crestal bone loss during submerged healing affects the prognosis of an implant. Hence, this study was conducted to estimate the early implant bone loss during the preprosthetic phase on bone level implants placed equicrestally. This retrospective observational study included evaluation of crestal bone loss around 271 two-piece implants placed in 149 patients from the archived postsurgical (P1) and preprosthetic (P2) digital orthopantomographic records using MicroDicom software. The outcome was categorized based on (1) sex (male or female), (2) time of implant placement (immediate [I] vs conventional [D]), (3) duration of healing period before loading (conventional [T1] vs delayed [T2]), (4) region of implant placement (maxilla [M1] vs mandible [M2]), and (5) site of implant placement (anterior [A] vs posterior [P]). To find the significant difference between the bivariate samples in the independent groups, an unpaired sample t test was used. The average marginal bone loss during the healing phase was 0.56 ± 0.573 mm in the mesial region and 0.44 ± 0.549 mm in the distal region of the implant, with a statistically significant difference (P < .01). There was no statistically significant difference in crestal bone level with the (1) sex of the patient (male or female), (2) type of implant placement (I or D), (3) time of implant loading (T1 or T2), (4) region of implant placement (M1 or M2), or (5) site of implant in the arch (A or P) (P > .05). An average of 0.50 mm crestal bone loss occurred in the peri-implant region during the preprosthetic phase. We found that the delayed placement of an implant and a delay in the healing period would further increase the early implant bone loss. The difference in the healing period did not alter the outcome of the study.

Comparing clinical outcomes of immediate implant placement with early implant placement in healthy adult patients requiring single-tooth replacement in the aesthetic zone: a systematic review and meta-analysis of randomised controlled trials

BACKGROUND

The aim of this systematic review and meta-analysis was to assess the clinical efficacy of the immediate implant placement (IIP) protocol in the aesthetic zone with early dental implant placement (EIP) protocol.

METHODS

Electronic databases MEDLINE (via OVID), EMBASE (via OVID), ISI Web of Science core collection, Cochrane, SCOPUS, and Google Scholar were searched for the studies comparing the two clinical protocols. Randomised controlled trials were included. Cochrane Risk of Bias tool (ROB-2) was used to assess the quality of included students.

RESULTS

A total of six studies were selected. Implant failure was observed at 3.84%, 9.3%, and 4.45% in three studies while in the other studies, no implant failure was reported. Meta-analysis of four studies showed no statistically significant difference in the vertical bone levels between IIP and EIP (148 patients), mean difference (MD)0.10 [95% CI: -0.29 to 0.091.32] P > 0.05. Meta-analysis of two studies showed the probing depth between IIP versus EIP was not significantly different (100 patients), mean difference(MD)-0.00 [95% CI; -0.23 to 0.23]; P > 0.05. The pink aesthetic score (PES) was improved in EIP as compared to IIP with a statistically significant difference (P < 0.05).

CONCLUSION

The available evidence supports the clinical efficacy of the IIP protocol. Present findings indicate aesthetics and clinical results of immediate implant placement protocol are comparable to early and delayed placement protocols. Therefore, future research with long-term follow-up is warranted.

Restoring the electrical microenvironment using ferroelectric nanocomposite membranes to enhance alveolar ridge regeneration in a mini-pig preclinical model

The maintenance and incremental growth of the alveolar bone at the tooth extraction site, to achieve the required height and width for implant restoration, remains a major clinical challenge. Here, the concept of restoring the electrical microenvironment to improve the effects of alveolar ridge preservation (ARP) was investigated in a mini-pig preclinical model. The endogeneous electrical microenvironment of the dental alveolar socket was recapitulated by fabricating a biomimetic ferroelectric BaTiO₃/poly(vinylidene fluoridetrifluoroethylene) (BTO/P(VDF-TrFE)) non-resorbable nanocomposite membrane polarized by corona poling. The polarized nanocomposite membrane exhibited excellent electrical stability. After implantation with bone grafts and covering with the charged membrane in tooth extraction sites for three months, both the vertical and horizontal dimension resorption of the alveolar ridge were significantly prevented, as assessed by cone beam computed tomography (CBCT) analyses. Micro-CT analysis showed that the charged membrane induced significant enhancement of newly regenerated bone at the tooth extraction sites. Histological analysis further confirmed that the restoration of the electrical microenvironment significantly promoted buccal alveolar bone regeneration and maturation. In addition, the charged membranes can maintain their structural integrity during the entire implantation period and exhibit positive long-term systemic safety, as assessed by preclinical sub-chronic systemic toxicity. These findings thus provide an innovative strategy for restoring the electrical microenvironment to enhance ARP following dentition defect and edentulism, which could further advance prosthodontics implant technology.

Comparative Evaluation of the Crestal Bone Level Around Pre- and Post-loaded Immediate Endoosseous Implants Using Cone-Beam Computed Tomography: A Clinico-Radiographic Study

Introduction  Dental implants replace missing teeth. Dental implants are surgically placed tooth root replacements that secure prosthetic teeth and bridges. Branemark's original dental implant technique included a mesiobuccal flap and a two-stage approach, needing 6-8 months of recovery following extraction, sterile conditions, machined titanium implants, 3-6 months without stress for osseointegration, and a detachable temporary prosthesis. The restoration would usually be ready a year following the implant surgery. Implant treatment seeks the best function, aesthetics, and complication risk. Implant therapy with low patient morbidity and fast extraction-to-restoration times is a secondary target. Instantaneous implant insertion has made implant dentistry more convenient for patients and clinicians. This study measures bone height before, after, and one month after implant placement using cone-beam computed tomography (CBCT). Materials and Methods Participants were selected from oral evaluation candidates. This investigation included 11 people missing front maxillary or mandibular teeth or root components. Diagnostic castings determined the interarch connection before surgery. Alginate maxillary and mandibular arch imprints were cast in Type III dental stone for diagnosis. CBCT scans were taken pre-operatively, post-implant, and post-prosthesis. After the tooth was removed, the empty socket was cleaned up with curettes. An intraoral periapical radiograph and manual probing were done to determine the implant's size. The implant was removed for examination after three months, and healing abutments and gingival formers were placed. Finally, fins were placed. The CBCT images also captured the bone height around the implants. The soft tissue parameters were recorded and evaluated at baseline and one-month following prosthetic loading as plaque index (PI). Radiographic evaluation was done at baseline and one-month following functional loading using CBCT. After one month following functional loading, crestal bone levels were measured again with the help of CBCT using Image J software (National Institutes of Health, Bethesda, Maryland, US). Results The sample population had an average age of 42.81 years, with a standard deviation of 13.44 years. Using a paired t-test, we found that the mean PI dropped significantly from pre-loading levels to one-month post-loading levels, with a p-value of less than 0.001. The mean crestal bone level (mesial) evaluated by CBCT at baseline and one-month post-loading was 2.52 ± 1.97 mm and 1.17 ± 1.31 mm, respectively. The mean difference between mean crestal bone loss (distal) at baseline and one-month post-loading was 0.94 ± 1.89 mm, which was not statistically significant. The mean difference between mean crestal bone loss (buccal) at baseline and one-month post-loading was 1.82 ± 1.60 mm, which was statistically significant. The mean difference between mean crestal bone loss (lingual) at baseline and one-month post-loading was 1.91 ± 1.53 which was statistically significant. Conclusion CBCT provides all the diagnostic data needed for implant placement; hence, it is recommended.

Influence of Bone-Level Dental Implants Placement and of Cortical Thickness on Osseointegration: In Silico and In Vivo Analyses

The purpose of this research is to study the biomechanical response of dental implants in bone-level type locations, 0.5 mm above and below the bone level. In addition, the influence of the thickness of the cortical bone on osseointegration is determined due to the mechanical loads transfer from the dental implant to the cortical and trabecular bone. The thicknesses studied were 1.5 mm and 2.5 mm. Numerical simulations were performed using a finite element method (FEM)-based model. In order to verify the FEM model, the in silico results were compared with the results obtained from a histological analysis performed in an in vivo study with 30 New Zealand rabbits. FEM was performed using a computerized 3D model of bone-level dental implants inserted in the lower jawbone with an applied axial load of 100 N. The analysis was performed using different distances from the bone level and different thicknesses of cortical bone. The interface area of bone growth was evaluated by analyzing the bone–implant contact (BIC), region of interest (ROI) and total bone area (BAT) parameters obtained through an in vivo histological process and analyzed by scanning electron microscopy (SEM). Bone-level implants were inserted in the rabbit tibiae, with two implants placed per tibia. These parameters were evaluated after three or six weeks of implantation. FEM studies showed that placements 0.5 mm below the bone level presented lower values of stress distribution compared to the other studied placements. The lower levels of mechanical stress were then correlated with the in vivo studies, showing that this position presented the highest BIC value after three or six weeks of implantation. In this placement, vertical bone growth could be observed up the bone level. The smallest thickness of the study showed a better transfer of mechanical loads, which leads to a better osseointegration. In silico and in vivo results both concluded that the implants placed 0.5 mm below the cortical bone and with lower thicknesses presented the best biomechanical and histological behavior in terms of new bone formation, enhanced mechanical stability and optimum osseointegration.

Comparison of quality of bone and insertion torque values of early implants placed at 6 and 8 weeks in sockets preserved with advanced platelet-rich fibrin: A randomized controlled trial

Aim

Successful functional and esthetic rehabilitation of edentulous jaws with implants depends on the optimal timing of placement, surgical protocol, materials used, cost-effectiveness, and satisfying patient needs. Increasing demand for shorter treatment times necessitates the immediate placement protocol. However, researchers have demonstrateda higher failure rate. A-PRF (Advanced platelet-rich fibrin) has exhibited accelerated bone regeneration potential. Early implant placement with a limited healing period, along with A-PRF, can be beneficial over conventional and immediate implant placement.

Settings and Design

This prospective randomized clinical trial aims to assess the outcome of early implant placement in sockets preserved using A-PRF at six weeks and eight weeks of post-extraction. Two groups of 10 participantseach were formed. All patients underwent atraumatic extraction and socket preservation using A-PRF.

Materials and Methods

A Partial-thickness pedicle graft was raised, and the extraction socket wasclosed. Implants wereplaced in at six and eight weeks of post-extraction in group A group B, respectively. The histomorphometric analysisassessedthe bone quality present at the timeof surgery. The insertion torque values were recorded during implant placement.

Statistical Analysis Used

The obtained data were statistically analyzed using parametric tests, namely independent T-test for intergroup comparison.

Results

T-test for torque values indicated a significantly higher torque value at eight weeks. The meanhistomorphometric value showeda significantly higher percentage of bone formation at eight weeks than at six weeks (P = 0.03).

Conclusion

Within the study's limitations, early implant placement in extraction sockets preserved with A-PRF had significantly higher insertion torque values and predictable bone at eight weeks compared to six weeks.

Do the location and dimensions of the mental foramen differ among individuals of different facial types and skeletal classes? A CBCT study

STATEMENT OF PROBLEM

Knowledge about the location and dimensions of the mental foramen is important for surgical planning and implant placement in the posterior mandibular region.

PURPOSE

The purpose of this clinical study was to assess the location and dimensions of the mental foramen in individuals of different facial type, skeletal class, and sex by means of cone beam computed tomography (CBCT) images.

MATERIAL AND METHODS

CBCT images of 142 individuals (72 women and 70 men) were classified according to the facial type (dolichocephalic, mesocephalic, or brachycephalic) and skeletal class (I, II, or III). The vertical and horizontal locations of each mental foramen were evaluated on panoramic reconstructions, and the greatest height and width of the mental foramen were determined on multiplanar reconstructions. Also, the distances from the mental foramen to the alveolar crest and to the inferior cortex of the mandible were obtained. The data were compared by using the Kruskal-Wallis test and multiway analysis of variance (α=.05).

RESULTS

The facial type, skeletal class, and sex did not influence the vertical (P=1.00) or the horizontal (P>.15) location of the mental foramen. The most frequent location of the mental foramen was between the first and second premolars and below their apices. The dimensions of the mental foramen were not influenced by the studied factors in men (P>.07); conversely, the mental foramen dimensions were influenced for women (P<.03).

CONCLUSIONS

The most frequent location of the mental foramen was between the first and second premolars and below their apices. An influence of the facial type and skeletal class was observed on the dimensions of the mental foramen in women.

Early implant placement with or without alveolar ridge preservation in single tooth gaps renders similar esthetic, clinical and patient-reported outcome measures: One-year results of a randomized clinical trial

Objectives

To test whether early implant placement with alveolar ridge preservation (ARP) results in different esthetic, clinical and patient‐reported outcome measures (PROMs) compared with early implant placement without ARP.

Material and methods

Seventy‐five patients requiring single tooth extraction in the anterior maxilla were recruited. Following tooth extraction, the patients were randomly allocated to three groups: (a) ARP using demineralized bovine bone mineral containing 10% collagen (DBBM‐C) covered by a collagen matrix (CM) (n = 25), (b) ARP using DBBM‐C covered with a palatal graft (PG) (n = 25) and (c) spontaneous healing (control) (n = 25). Eight weeks after tooth extraction, a CBCT was taken and early implant placement was performed in all patients. Esthetic, clinical and PROMs were evaluated one year post‐loading.

Results

A total of 70 patients were available for re‐examination at one year post‐loading. The median mid‐facial mucosal margin change amounted to −0.02 mm (IQR −0.27–0.46) in the CM group, −0.13 mm (IQR −0.44–0.25) in the PG group and −0.14 mm (IQR −0.29–0.07) in the control group, with no significant differences between the groups. Mean PES scores amounted to 7.0 ± 1.4 in the CM group, 7.1 ± 1.5 in the PG group and 7.3 ± 1.7 in the control group without significant differences between the groups. Plaque, bleeding on probing and probing depth did not differ between treatment groups. PROMs in general revealed no significant differences between the groups.

Conclusion

Early implant placement with ARP using either a collagen matrix or a palatal graft rendered similar esthetic, clinical and PROMs to early implant placement without ARP. When a failing tooth can be replaced with an implant within 2 months after tooth extraction, the added value of ARP might be clinically negligible.

The ability to screw-retain single implant-supported restorations in the anterior maxilla: A CBCT analysis

STATEMENT OF PROBLEM

Evidence to validate the routine use of angled screw-channel abutments in the anterior maxilla is sparse. If properly planned, they might provide surgical and prosthetic benefits.

PURPOSE

The purpose of this observational study was to determine the prevalence of digitally placed implants in the anterior maxilla that would allow screw-retained implant-supported restorations with either a straight or an angled screw-channel abutment.

MATERIAL AND METHODS

Two hundred cone beam computed tomography (CBCT) scans met the inclusion criteria for retrospective analysis and digital implant planning. Virtual implants were planned for randomly selected anterior maxillary teeth by using the anatomic crown and root position. Virtual abutments of varying angulation were attached to the implants to determine the ability to screw retain a restoration with either a straight or an angled screw-channel abutment.

RESULTS

One hundred fifty-two (76%) sites required an angled screw-channel abutment to enable screw retention. Forty-eight (24%) sites allowed screw retention with a straight abutment. The percentage of implants requiring angled or straight abutments varied significantly among anterior teeth (P<.005). One hundred nine (71.7%) angled screw-channel abutment sites required a 5-degree abutment, 41 (26.9%) required a 10-degree abutment, and 2 (1.3%) required a 15-degree abutment. Among the anterior teeth, lateral incisors presented a greater need for angled screw-channel abutments. None of the implants in the present study needed cement-retained restorations.

CONCLUSIONS

Angled abutments allowed for screw-retained restorations on digitally planned implants in the anterior maxilla. The required angular correction to a screw-retained restoration was ≤15 degrees. Screw-retained restorations were frequently achievable (76%) with the use of angled screw-channel abutments or with straight abutments (24%), and lateral incisors presented a greater need for angled screw-channel abutments.

Effectiveness and clinical performance of early implant placement for the replacement of single teeth in anterior areas: A systematic review

AIM

To assess the effectiveness and clinical performance of early implant placement, 4-8 (Type 2) or 12-16 weeks (Type 3) after extraction, in single anterior sites.

METHODS

Studies reporting on Type 2 and Type 3 implant placement were identified. Findings were summarized in evidence tables. Main outcome was implant survival. Peri-implant soft and hard tissues changes, periodontal parameters, aesthetics and patient-reported outcomes were also evaluated. Quality of reporting of the included studies was evaluated through Consort, Newcastle-Ottawa scale and IHE quality appraisal checklist.

RESULTS

Nineteen eligible articles (seven from one RCT, three from two CCTs and nine from three case series) reporting on 140 patients and 140 implants were included. Type 3 implants showed comparable results to Type 4: 95% vs. 100% survival rates. Studies reported high values of implant survival, minimal technical and biological complications and high aesthetic scores in both short and long-term follow-ups for both Type 2 and Type 3 implant placement. Quality evaluation highlighted important weaknesses in the included trials.

CONCLUSIONS

Limited data on Type 2 and Type 3 implant placement appear to indicate that they can perform well both short and long term. However, the limited number of cases, the significant heterogeneity of the included studies and the high risk of biases importantly reduce the generalizability of the findings. CRD42018117363.

Effects of local application of alendronate on early healing of extraction socket in dogs

OBJECTIVE

The aim of the present study was to assess the effects of alendronate (ALN) on bone remodeling following tooth extraction in a dog model.

MATERIAL AND METHODS

For the study, fifteen male Beagles dogs of approximately 12 months of age were used. Mesial roots of four mandibular premolars were endodontically treated, and the distal roots were removed. ALN concentrations of 0.5, 1, and 2 mg/mL were topically applied for 15 min, while a sterile saline was used as a negative control. After the healing period of 1, 2, and 8 weeks, the samples were analyzed by micro-CT and histology.

RESULTS

Treatment with ALN increased vertical distance between the lingual and the buccal crestal bones. While the ALN-treated sockets had preserved more lingual bone areas, control sockets showed better preservation of the buccal bone areas. ALN treatment resulted in more osteoid formation within the extraction sockets compared with the control. Higher bone volume was found in ALN groups than in the control at 2-week and 8-week healing periods, reaching the significant difference only for the extraction sockets pooled for the ALN treatment.

CONCLUSIONS

Although ALN treatment could not prevent buccal bone resorption following tooth extraction in dogs, it proved beneficial for the preservation of the lingual bone and formation of new bone within the socket. There was no clear relation between the ALN dosages and the alterations within the extraction sockets.

CLINICAL RELEVANCE

ALN affects bone remodeling of the extraction socket. The optimal concentration remains to be determined in future studies.

Comparison of Different Bone Filling Materials and Resorbable Membranes by Means of Micro-Tomography. A Preliminary Study in Rabbits

The purpose of this work was to evaluate the behavior of different membranes and bone filling materials used to fill critical defects in rabbit calvaria. Four defects were prepared in the cranial calvaria of female rabbits. They were randomly divided into three subgroups according to the type of barrier membrane to be used. Four animals carried cross-linked bovine collagen membranes (Mem-Lok, Bio-Horizons, Birmingham, AL, USA)), four human fascia lata membranes (Tissue, Inbiomed SA, Córdoba, Argentina) and four human chorioamniotic membranes (Tissue. Inbiomed SA, Córdoba, Argentina). The defects were filled with the deproteinized bovine bone particulate Bio-Oss® (Geistlich-Pharma AG, Wolhusen, Switzerland), with particulate human hydroxyapatite MinerOss® (Bio-Horizons, Birmingham, AL, USA), with particulate dental material (Tissue Bank Foundation, Inbiomed S.A., Córdoba, Argentina), and the last one was left without the addition of filler material. In the first group of four specimens, a resorbable cross-linked bovine collagen membrane was placed over the skull and defects, without additional fixing. In the second group, a human fascia lata membrane was placed, without additional fixing. In the third group, a human chorioamniotic membrane was placed, without additional fixing. The animals were sacrificed at 4 and 8 weeks. The highest percentages of relative radiological density (average) were recorded considering the amnio-chorionic membranes (83.63%) followed by collagen (81.44%) and finally the fascia lata membranes (80.63%), but the differences were not statistically significant (p > 0.05). The sites grafted with a decellularized tooth (96.83%) and Bio-Oss (88.42%), recorded the highest percentages of radiological density but did not differ significantly from each other (subset 2). The three membranes used did not show statistical differences between them, in any of the two time periods used. There were statistical differences between the filling materials evidencing the presence of a large quantity of calcified material in the defects treated with particulate tooth and deproteinized bovine bone and while smaller amounts of calcified material were registered in the case of defects treated with human hydroxyapatite and those that were not treated.

Outcome of early dental implant placement versus other dental implant placement protocols: A systematic review and meta-analysis

BACKGROUND

The aim of this systematic review and meta-analysis was to compare the clinical efficacy of the early dental implant placement protocol with immediate and delayed dental implant placement protocols.

METHODS

An electronic and manual search of literature was made to identify clinical studies comparing early implant placement with immediate or delayed placement. Data from the included studies were pooled and quantitative analyses were performed for the implant outcomes reported as the number of failed implants (primary outcome variable) and for changes in peri-implant marginal bone level, peri-implant probing depth, and peri-implant soft tissue level (secondary outcome variables).

RESULTS

Twelve studies met the inclusion criteria. Significant difference in risk of implant failure was found neither between the early and immediate placement protocols (risk difference = -0.018; 95% confidence interval [CI] = -0.06, 0.025; P = 0.416) nor between early and delayed placement protocols (risk difference = -0.008; 95% CI = -0.044, 0.028; P = 0.670). Pooled data of changes in peri-implant marginal bone level demonstrated significantly less marginal bone loss for implants placed using the early placement protocol compared with those placed in fresh extraction sockets (P = 0.001; weighted mean difference = -0.14 mm; 95% CI = -0.22, -0.05). No significant differences were found between the protocols for the other variables.

CONCLUSIONS

The available evidence supports the clinical efficacy of the early implant placement protocol. Present findings indicate that the early implant placement protocol results in implant outcomes similar to immediate and delayed placement protocols and a superior stability of peri-implant hard tissue compared with immediate implant placement.

Recombinant human BMP9 (RhBMP9) in comparison with rhBMP2 for ridge augmentation following tooth extraction: An experimental study in the Beagle dog

OBJECTIVES

The purpose of this study was to compare the effects of rhBMP2 with rhBMP9 on ridge augmentation following healing of extraction sockets in dogs.

MATERIAL AND METHODS

Five male Beagle dogs, approximately 12 months of age, were used. The mesial roots of the four maxillary premolars were endodontically treated. The distal roots were extracted, and the buccal bony walls removed. All extraction sockets were filled with deproteinized bovine bone mineral (DBBM). A collagen membrane was soaked with 4 μg or 20 μg of rhBMP9, 20 μg of rhBMP2 or sterile saline and placed over the augmented sites. All animals were euthanized after 8 weeks of healing and investigated by micro-CT and histologic analysis. A one-way ANOVA with Tukey's HSD post hoc test was used to compare the differences between the four groups.

RESULTS

New bone apposition in all defects was observed from the original bone. RhBMP samples showed an increase in bone formation in the buccal area and better integration of DBBM particles when compared to control sites. Both rhBMP9 defects showed higher values of bone (p = 0.024), bone marrow (p = 0.044), and total augmentation volume (p = 0.033) than the rhBMP2 (20 μg) or control sites. Highest bone area was found in rhBMP9 defects (p = 0.895).

CONCLUSIONS

Within the limitations of the present study, rhBMP9 sites demonstrated higher bone-inducing potential in combination with DBBM than rhBMP2. While rhBMP9s failed to demonstrate a clear dose-response relationship to the outcomes, future studies are necessary to evaluate the appropriate dose and carrier systems.

Implant placement and loading protocols in partially edentulous patients: A systematic review

OBJECTIVES

To systematically review the evidence for the clinical outcome of fixed implant prostheses treated with different combinations of implant placement and loading protocols in partially edentulous patients.

MATERIALS AND METHODS

An electronic search was performed in Medline, Embase, and Central to identify studies investigating the outcome of implants subjected to immediate placement + immediate restoration/loading (Type 1A), immediate placement + early loading (Type 1B), immediate placement + conventional loading (Type 1C), early placement + immediate restoration/loading (Type 2-3A), early placement + early loading (Type 2-3B), early placement + conventional loading (Type 2-3C), late placement + immediate restoration/loading (Type 4A), late placement + early loading (Type 4B), late placement + conventional loading (Type 4C) with implant-supported fixed dental prostheses (IFDPs) in partially edentulous patients. Only human studies with at least 10 cases and a minimum follow-up time of 12 months, reporting on solid-screw-type implants with rough surfaces and an intra-osseous diameter between 3 and 6 mm, were included. A cumulative survival rate for each type of the implant placement and loading protocols was weighted by the duration of follow-up and number of implants.

RESULTS

The search provided 5,248 titles from which 2,362 abstracts and 449 full-text articles were screened. A total of 69 publications that comprised 23 comparative studies (15 randomized controlled trials, 7 controlled clinical trials) and 47 noncomparative studies (34 prospective cohort studies, 13 retrospective cohort studies) were included for analysis. Considerable heterogeneity in study design was found, and therefore, a meta-analysis of controlled studies was not possible. The weighted cumulative survival rate of each type of placement and loading protocol was 98.4% (Type 1A), 98.2% (Type 1B), 96.0% (Type 1C), 100% (Type 2-3B), 96.3% (Type 2-3C), 97.9% (Type 4A), 98.3% (Type 4B), and 97.7% (Type 4C). Type 1C, Type 2-3C, Type 4B, and Type 4C were scientifically and clinically validated (SCV). Type 1A, Type 1B, and Type 4A were clinically documented (CD), and Type 2-3A and Type 2-3B were clinically insufficiently documented (CID).

CONCLUSIONS

Evaluating outcomes in oral implantology by combining the placement and loading protocols are paramount. The selected loading protocol appears to influence the outcome of immediate implant placement.

Alveolar ridge preservation with a collagen material: a randomized controlled trial

Purpose

Resorption of the alveolar bone is an unavoidable consequence of tooth extraction when appropriate alveolar ridge preservation (ARP) measures are not taken. The objective of this trial was to test the hypothesis that dimensional changes in the alveolar bone after tooth extraction would be reduced by inserting an equine collagen membrane and a collagen cone to fill and seal the alveolus (as ARP), in comparison to extraction with untreated alveoli.

Methods

In this randomized clinical trial, 31 patients were directly treated with the collagen material after extraction of a tooth from the maxilla (the ARP group). Twenty-nine patients served as the control group. After extraction, no further treatment (i.e., no socket preservation measures) was performed in the control group. Changes in the alveolar process immediately after extraction and after an 8 (±1)-week healing period were evaluated 3-dimensionally. Blinded analyses were performed after superimposing the data from the digitalized impressions and surfaces generated by cone-beam computed tomography.

Results

Both the ARP and control groups showed a reduction of bone in the alveolar area after tooth extraction. However, significantly less bone resorption was detected in the clinically relevant buccal region in the ARP group. The median bone reduction was 1.18 mm in the ARP group and 5.06 mm in the control group (P=0.03).

Conclusions

The proposed hypothesis that inserting a combination material comprising a collagen cone and membrane would lead to a difference in alveolar bone preservation can be accepted for the clinically relevant buccal distance. In this area, implantation of the collagen material led to significantly less alveolar bone resorption. German Clinical Trials Register at www.drks.de, DRKS00004769.

Guided bone regeneration using K-incision technique

Purpose

The present study describes 3 patients with chronic periodontitis and consequent vertical resorption of the alveolar ridge who were treated using implant-based restoration with guided bone regeneration (GBR).

Methods

After extraction of a periodontally compromised tooth, vertical bone augmentation using a K-incision was performed at the healed, low-level alveolar ridge.

Results

The partial-split K-incision enabled soft tissue elongation without any change in buccal vestibular depth, and provided sufficient keratinized gingival tissue during GBR.

Conclusions

Within the limits of this study, the present case series demonstrated that the novel K-incision technique was effective for GBR and allowed normal implant-based restoration and maintenance of a healthy periodontal condition. However, further long-term follow-up and a large-scale randomized clinical investigation should be performed to evaluate the feasibility of this technique.

Post extractive implant: evaluation of the critical aspects

Purpose

Nowadays, implant supported prosthetic rehabilitation is a reliable procedure to replace compromised or untreatable teeth. The purpose of this review is to explore the concept of post extractive implant and the indications for clinical practice through an analysis of recent studies in the literature. All the main factors that could influence the outcome of this treatment will also be considered.

Materials and methods

Focusing on the extraction-socket healing time, three different implant insertion protocols have been defined: Immediate implant placement (IIP), Early implant placement (EIP), Delayed implant placement (DIP). The entity of bone remodeling can be associated with different factors: three dimensional implant position, presence/absence of platform switching, absence of facial bony wall, inter implant/tooth distance.

Results

All the studies in literature agreed that implant primary stability is the main condition for a successful osseointegration of dental implants. Primary implant stability is influenced by many factors including local bone quality and quantity, implant macro-design, soft tissue conditions and rehabilitation, surgical technique, prosthetic load timing, oral hygiene.

Conclusions

There is insufficient evidence in literature to determine possible advantages or disadvantages of IIP, EIP or DIP. Studies suggest that IIP and EIP may be at higher risks of implant failures and complications than delayed implants; on the other hand the aesthetic outcome might be better when placing implants just after teeth extraction.

Clinical relevance of dimensional bone and soft tissue alterations post-extraction in esthetic sites

The key to achieving pleasing esthetics in implant dentistry is a thorough understanding of the biological processes driving dimensional bone and soft tissue alterations post-extraction. The aim of the present report is first to characterize the extent of bone and soft tissue changes post-extraction and second to identify potential factors influencing tissue preservation in order to facilitate successful treatment outcomes. The facial bone wall thickness has been identified as the most critical factor influencing bone resorption and can be used as a prognostic tool in order to identify sites at risk for future facial bone loss subsequent to tooth extraction. Clinical studies indicated that thin bone wall phenotypes exhibiting a facial bone wall thickness of 1 mm or less revealed progressive bone resorption with a vertical loss of 7.5 mm, whereas thick bone wall phenotypes showed only minor bone resorption with a vertical loss of 1.1 mm. This is in contrast to the dimensional soft tissue alterations. Thin bone wall phenotypes revealed a spontaneous soft tissue thickening after flapless extraction by a factor of seven, whereas thick bone wall phenotypes showed no significant changes in the soft tissue dimensions after 8 weeks of healing. In sites exhibiting a limited bone resorption rate, immediate implant placement may be considered. If such ideal conditions are not present, other timing protocols are recommended to achieve predictable and pleasing esthetics. Socket preservation techniques for ridge preservation utilizing different biomaterials and/or barrier membranes often result in a better maintenance of tissue volumes, although the inevitable biological process of post-extraction bone resorption and bone modeling cannot be arrested. In summary, the knowledge of the biological events driving dimensional tissue alterations post-extraction should be integrated into the comprehensive treatment plan in order to limit tissue loss and to maximize esthetic outcomes.

Survival rates and bone loss after immediate loading of implants in fresh extraction sockets (single gaps). A clinical prospective study with 4 year follow-up

Background

The aim of this prospective study was to report the outcome of treatment with implants inserted after tooth extraction and immediately loaded.

Material and Methods

Fifty-six patients with single tooth loss were treated with 116 IPX Galimplant® implants with internal connections and a sandblasted, acid-etched surface. All implants were placed after tooth extraction using a flapless approach without bone regeneration, and they were then immediately loaded with cemented acrylic prostheses. After a period of three months, definitive cemented ceramic prostheses were placed. Patients were examined throughout a total of 4 years of follow-up. Marginal bone loss and survival rates were evaluated using digital periapical radiographs, taking into account clinical variables such as age, gender, smoking, history of periodontitis, etiology of extraction, placement site, diameter, and implant length. The Mann-Whitney U and Kruskal-Wallis non-parametric tests were used to compare differences between subgroups created based on the different clinical variables identified.

Results

Clinical results indicate an implant survival and success rate of 97.4%. Three implants were lost. Of the 116 immediate acrylic single crowns initially placed, 113 were replaced with definitive ceramic crowns after 3 months. A total of 77.8% of implants were inserted in the maxilla, while 22.2% were inserted in the mandible. No further complications were reported after the follow-up period (4 years). The mean marginal bone loss was 0.67 mm ± 0.40 mm. No differences were found among the subgroups of study patients.

Conclusions

This study indicates that dental implants that are inserted after tooth extraction and immediately loaded may constitute a successful and predictable alternative implant treatment.

Key words:Dental implants, post-extraction implants, fresh sockets, immediate loading, immediate prostheses, implant dentistry.

Volumetric changes following ridge preservation or spontaneous healing and early implant placement with simultaneous guided bone regeneration

AIM

To assess volumetric and linear changes following ridge preservation (RP) or spontaneous healing plus early implant placement with or without simultaneous guided bone regeneration (GBR).

MATERIALS AND METHODS

In eight adult beagle dogs, the mesial roots of the mandibular P3, P4 and M1 were extracted. Sites were randomized to either ridge preservation (RP) or spontaneous healing (SH). Four weeks later dental implants were placed either with (RP2) or without removing non-integrated DBBM (RP1). In RP2 and SH sites, GBR was applied using a demineralized bovine bone mineral and a resorbable membrane. Impressions were taken postextraction (SH)/postridge preservation (RP1; RP2), before and after implant placement and after healing of 4 and 12 weeks. Casts were digitized to allow for superimposition and measurement of contour alterations.

RESULTS

Median ridge width reduction from postextraction (SH)/postridge preservation (RP1;RP2) to implant placement ranged from -13.9% (SH) to -19.7% (RP) (p > .05), whereas from implant placement to sacrifice, it was statistically significantly lower in group RP1 (-5.5%) compared to group SH (-23.4%; p = .0013) and group RP2 (-22.1%; p = .0026). Encompassing the entire study period, median ridge width changes ranged between -17.8% (SH), -24.8% (RP2) and -32.5% (RP1) (p > .05).

CONCLUSIONS

Irrespective of the treatment modality and the healing period, part of the ridge contour was lost. Early implant placement after ridge preservation without additional GBR resulted in a more stable ridge contour after implant placement compared to controls.

Preservation of extraction socket in immediate implant placement: a clinical study

AIM

The objective of this study was to compare different approaches temporary restoration in an immediate implant placement. To determine the respective influence of each parameter, two treatment groups were formed; a strict and standardized study protocol was applied to minimize the influence of bias and confounding factors. The Pink Esthetic Score (PES) - the esthetic out-come of soft tissue appearance was evaluated.

MATERIAL AND METHODS

Sixteen patients with a single failing tooth in the maxilla and a natural contralateral site were randomly distributed into two groups. Treatment variations affected the provisional restorative in detail, group 1 with immediate implant placement and immediate temporary restoration with the simulation of the first three mm of the root and the seal of the socket, group 2 with immediate implant placement and immediate temporary restoration without the seal of the socket. All patients received the final prosthetic restoration 10-12 weeks after implant placement. Standardized photographs were taken eight months after tooth extraction. Five competent observers analyzed the esthetic outcome according to the PES.

RESULTS

The overall scores of the four treatment groups revealed PES values of 8.47 (SD 2.08, group 1), 6.62 (SD 3.24, group 2). The differences between groups 1 and 2 and were statistically significant (P=0.015 and P=0.047). The single parameter analysis displayed a certain range of fluctuation and heterogeneity.

CONCLUSIONS

Immediate implant placement and restoration appear to be a suitable alternative to early implant placement if an experienced surgeon is entrusted with the implantation procedure.

A randomized, 12-month controlled trial to evaluate non-inferiority of early compared to conventional loading of modSLA implants in single tooth gaps

Background

The aim of the study was to evaluate whether early loading of implants with a chemically modified sandblasted, large-grit, acid-etched (SLA) (SLActive®) surface was non-inferior to conventional loading in terms of change in crestal bone level.

Methods

This was a randomized, controlled, multicenter study. Patients requiring single-tooth rehabilitation in the posterior maxilla or mandible received implants and were randomized to receive a provisional restoration in occlusal load after 25 ± 3 days (early loading) or after 13 ± 1 weeks (conventional loading). The primary endpoint was change in crestal bone level between implant placement (baseline) and 6 months. Secondary endpoints included change in crestal bone level between baseline and 12 months, implant survival and success rates, and patient satisfaction.

Results

Of the 84 patients enrolled, 78 received implants and were randomized onto the early loading (41 patients) and conventional loading (37 patients) groups. The mean change in crestal bone level between baseline and 6 months was 0.56 ± 0.58 and 0.51 ± 0.62 mm for early and conventional loading, respectively; at 12 months, the mean change was 0.76 ± 0.60 and 0.73 ± 0.77 mm, respectively. Implant survival and success at 12 months were 100 % for both groups. Patient satisfaction was similar between the groups, except that more patients in the early loading group were satisfied or highly satisfied with the time taken for fitting.

Conclusion

The study demonstrated that early implant loading was non-inferior to conventional implant loading in terms of crestal bone level change in a Japanese patient population in short follow-up period and single tooth gaps in molar regions.

Protocol for Bone Augmentation with Simultaneous Early Implant Placement: A Retrospective Multicenter Clinical Study

Purpose. To present a novel protocol for alveolar bone regeneration in parallel to early implant placement. Methods. 497 patients in need of extraction and early implant placement with simultaneous bone augmentation were treated in a period of 10 years. In all patients the same specific method was followed and grafting was performed utilizing in situ hardening fully resorbable alloplastic grafting materials consisting of β-tricalcium phosphate and calcium sulfate. The protocol involved atraumatic extraction, implant placement after 4 weeks with simultaneous bone augmentation, and loading of the implant 12 weeks after placement and grafting. Follow-up periods ranged from 6 months to 10 years (mean of 4 years). Results. A total of 601 postextraction sites were rehabilitated in 497 patients utilizing the novel protocol. Three implants failed before loading and three implants failed one year after loading, leaving an overall survival rate of 99.0%. Conclusions. This standardized protocol allows successful long-term functional results regarding alveolar bone regeneration and implant rehabilitation. The concept of placing the implant 4 weeks after extraction, augmenting the bone around the implant utilizing fully resorbable, biomechanically stable, alloplastic materials, and loading the implant at 12 weeks seems to offer advantages when compared with traditional treatment modalities.

Extraction Socket Management Utilizing Platelet Rich Fibrin: A Proof-of-Principle Study of the "Accelerated-Early Implant Placement" Concept

Dental implants are widely accepted as the golden standard for the rehabilitation of an edentulous site following the extraction of a tooth. The ideal time for implant placement is dependent on the time required for partial or complete tissue healing and the adequacy of socket dimensions. The use of autologous growth factors is a promising new concept that aids clinicians in minimizing treatment time and increasing patient satisfaction. The purpose of this paper is to introduce a protocol for "accelerated-early" implant placement. In this protocol, platelet rich fibrin is employed to accelerate soft and hard tissue healing and to provide a better-healed recipient site for accelerated, early implant placement. Histological analysis revealed that at 6 weeks postextraction, the application of our approach resulted in delicate newly formed bone showing intense osteoblastic activity surrounded by connective tissue as well as areas of mineralized tissue. The present study is a proof-of-principle study of the acceleration of the physiologic postextraction healing sequelae with the use of autologous growth factors. The accelerated-early implant placement concept is a bioengineered protocol that may aid clinicians to achieve increased primary stability, by placing implants in ridges in an advanced stage of bone healing, while offering patients the benefits associated with early implant placement. Controlled studies are warranted to verify the reproducibility of this treatment concept and identify specific indications where the use of the presented technique can lead to significant clinical results.

Strategies for alveolar ridge reconstruction and preservation for implant therapy

PURPOSE

In dental implant treatment, ridge preservation and immediate or early implant placement are recommended to minimize bone resorption after tooth extraction and achieve esthetic outcomes. However, there is no consensus concerning the efficacy of this surgical method. There is also no consensus on the efficacy of bone and soft tissue grafts and surgical methods for alveolar ridge reconstruction.

STUDY SELECTION

This paper reports ridge alteration in the anterior maxilla after tooth extraction, and summarizes the efficacy of various ridge preservation methods and immediate or early implant placement as alveolar ridge preservation methods to minimize bone resorption after tooth extraction. The advantages and complications of alveolar ridge reconstruction methods, and the efficacy and surgical method of soft tissue graft are reviewed.

RESULTS

The anterior maxilla is in the esthetic zone, and the thickness of the bone on the labial side around the natural tooth is less than 1mm in many cases. Therefore, it is impossible to prevent bone resorption completely, even if ridge preservation and immediate or early implant placement are performed after tooth extraction. It is necessary to obtain stable and long-term esthetics by combining connective tissue and free gingival grafts, in addition to hard tissue augmentation.

CONCLUSIONS

It is important to consider the burden and level of satisfaction of patients, such as in terms of donor site morbidity in hard and soft tissue grafting, and to pay attention to appropriate indications to avoid overtreatment.

Early peri-implant bone loss: a prospective cohort study

The aim of this study was to measure the early peri-implant bone level changes before the completion of an implant-abutment connection and to evaluate the influence of demographic, biologically relevant, anatomical, and implant-specific variables on these changes. A prospective cohort study design was used. STROBE guidelines were followed. The sample comprised 493 implants placed using a two-stage surgical procedure. Random allocation was used to determine the implant placement depth. Peri-apical radiographs taken at implant insertion and at the second surgery 2 months later were matched. Kappa statistics were used to compute intra- and inter-examiner reliability. The statistical analysis was performed at the implant level. Two-way analysis of variance (ANOVA) with the Bonferroni adjusted post hoc test was used to evaluate the influence of variables. One-way ANOVA with Tukey's range test and unpaired Student t-tests were used to analyze significant variables. Early marginal bone remodelling was -0.86 mm. The timing of implant placement (P=0.00) and the depth of implant placement (P≤0.05) significantly influenced early bone remodelling. Relevant radiographic early bone loss was found, but implants initially positioned below the alveolar crest and inserted ≥3 months after tooth extraction showed statistically significant higher marginal bone loss during the healing phase.

Papilla dimension and soft tissue level after early vs. delayed placement of single-tooth implants: 10-year results from a randomized controlled clinical trial

AIM

To present the10-year esthetic outcome data for single-tooth implants placed early or delayed after tooth extraction.

MATERIAL AND METHODS

Forty-four patients randomly allocated to two equal size groups were treated with a single-tooth implant approximately 10 days (Ea; N = 22), or 3 months (De; N = 22) after tooth extraction. Healing abutments were mounted after 3 months of submerged healing, and metal-ceramic crowns cemented after one additional month. Presence of buccal bone defects was registered at the second-stage surgery. Patients attended control visits 1 week and 1-1.5 years after mounting of the crown and 5 and 10 years after implant placement. Marginal bone level at the implant and the adjacent teeth as well as the distance between the implant and the teeth were measured in standardized periapical radiographs. The papilla dimension and clinical crown height (CCH) were assessed on clinical photographs by an experienced prosthodontist.

RESULTS

Two Ea and one De implants failed to osseointegrate. Twenty-eight patients (13 Ea and 15 De) who attended all four control visits were included in the data analysis. Complete papilla fill interproximally was achieved in one-third of the cases and an appropriate clinical crown height in <60% after 10 years. Although not statistically significant, early-placed implants tended to be superior to delayed-placed implants regarding soft tissue appearance just after crown delivery and after 10 years. An improvement in papilla dimensions was seen during the follow-up period for both groups while the CCH was unchanged. The implant region (anterior vs. posterior) did not significantly influence the papilla or CCH scores while younger patients (<50 years of age) received significantly better papilla scores than older patients (≥ 50 years). An apically located bone level at the tooth neighboring the implant influenced negatively the papilla dimension. In contrast, the presence of a bone defect buccally to the implant at second-stage surgery did not have a negative impact on the CCH 10 years after implant placement.

CONCLUSION

Early placement of single-tooth implants after tooth extraction performed equally to delayed placement in regard to the esthetic outcome of the soft tissues after 10 years in function.

Fate of the buccal bone at implants placed early, delayed, or late after tooth extraction analyzed by cone beam CT: 10-year results from a randomized, controlled, clinical study

AIM

To present 10-year cone beam CT (CBCT) data on the fate of buccal bone at single-tooth implants placed early, delayed, or late after tooth extraction.

MATERIAL AND METHODS

Sixty-three of 72 patients, originally randomly allocated to three equal-size groups, received a single-tooth implant on average 10 days (Ea; N = 22), 3 months (De; N = 22), or 1.5 years (La; N = 19) after tooth extraction. Healing abutments were mounted after a 3-month period of submerged healing and metalceramic crowns were cemented after one additional month. At the second stage surgery, presence of buccal bone defects (dehiscences or intrabony) and their dimensions were registered. CBCT scans recorded with a Scanora(®) 3D unit and standardized periapical (PA) radiographs of the implants were obtained at the 10-year control. Interproximal bone levels (i.e., the distance from the implant platform to the first bone-to-implant contact; BIC) measured in CBCT image sections and PA were compared, and the buccal bone level was determined in the CBCT images.

RESULTS

Two Ea and one De implants failed to osseointegrate. Forty-nine patients attended the 10-year control and due to poor quality of 5 CBCT scans, useful CBCT images were available from 44 patients (Ea:12, De:17, La:15). No significant differences between CBCT and PA images in measurements of the interproximal bone levels were observed. Ten years after implant placement, BIC at the buccal aspect was located on average 2 mm apically to the implant platform (2.39 ± 1.06 mm [median = 2.36] for Ea, 2.22 ± 0.99 mm [median = 2.16] for De, and 1.85 ± 0.65 mm [median = 1.95] for La implants) with no significant difference among the groups (P = 0.20). Mean buccal bone level (bBL) for implants with an intrabony or a dehiscence defect at second stage surgery was 2.51 ± 1.12 mm [median = 2.70] and 2.84 ± 0.70 mm [median = 2.79], respectively, while 1.78 ± 0.74 mm [median = 1.93] for the implants with no defect. The difference in bBL between the implants without a defect and those with a dehiscence was significant at 10 years (P = 0.0005).

CONCLUSION

Time of placement of single-tooth implants after tooth extraction did not significantly influence the peri-implant buccal bone level, while presence of a buccal bone dehiscence at second stage surgery resulted in significantly more apically located BIC buccally at 10 years.

Soft Tissues Changes After Immediate and Delayed Single Implant Placement in Esthetic Area: A Systematic Review

The aim of the present study was to conduct a systematic review of the literature to compare soft tissue aspects of immediate and delayed implant placement in esthetic areas. This review of literature was conducted in the following databases: MEDLINE (PubMed), Lilacs, Scielo, EMBASE, and Cochrane Central Register of Controlled Trials (CENTRAL). For those studies that met the inclusion/exclusion criteria, the results were analyzed and summarized according to the treatment protocol used for implant placement. The primary parameters taken into consideration were papilla level (PL) and marginal mucosa level (MML) around implants. Four randomized controlled trials (RCT) were selected for analysis, but all were deemed as being of poor quality according to quality assessment. No studies reported any statistically significant differences concerning the soft tissue esthetic parameters analyzed around immediate or delayed implants at any follow-up periods reported. However, PL results seemed to be more reliable than were MML results, due to the PL standardization of the method of analysis, which showed a tendency for poorer results around immediately placed implants. In conclusion, although the results are based on only a few poor quality RCTs, both treatment options for implant placement demonstrated similar outcomes in the esthetic area, especially when PL was considered.

Risk assessment of inferior alveolar nerve injury for immediate implant placement in the posterior mandible: a virtual implant placement study

OBJECTIVES

To investigate the prevalence and morphological parameters of lingual concavity, and whether these factors are related to a higher risk of inferior alveolar nerve (IAN) injury when performing an immediate implant surgery in posterior mandible region.

METHODS

The CBCT images from 237 subjects (1008 teeth) were analysed the shape of the mandibles (C, P, U type), dimensional parameters of lingual concavity (angle, height, depth), and its relation to inferior alveolar canal (IAC) (A, B, C zone), RAC (distance from root apex to IAC) and probability of IAN injury. Multiple logistic regression modelling to determine the odds ratio of variables that made an important contribution to the probability of IAN injury and to adjust for confounding variables.

RESULTS

The U type ridge (46.7%) and the most concave point located at C zone (48.8%) are most prevalent in this region. The mandibular second molar presents highest risk for IAN injury than other tooth type (p<0.001), which were 3.82 times to occur IAN injury than the mandibular second premolar. The concave point located at A zone and B zone were 7.82 and 3.52 times than C zone to have IAN damage, respectively. The probability of IAN injury will reduce 26% for every 1mm increase in RAC (p<0.001).

CONCLUSIONS

The tooth type, morphological features of lingual concavities, and RAC are associated with risks of IAN injury during immediate implant placement.

CLINICAL SIGNIFICANCE

Pre-surgical mapping of the IAC and identification of its proximity relative to the lingual concavity in the posterior mandible regions may avoid unpleasant complications, specifically when performing immediate implant procedures.

Early, delayed, or late single implant placement: 10-year results from a randomized controlled clinical trial

AIM

The aim of this study was to present the 10-year clinical and radiographic data from a RCT on single-tooth implants placed early, delayed, or late after tooth extraction.

MATERIALS AND METHODS

Sixty-three patients were randomly allocated to three groups and received an implant on average 10 days (Ea), 3 months (De), or 17 months (La) after tooth extraction. Second-stage surgery was performed after 3 months of submerged healing; metal-ceramic crowns were cemented after one additional month. Standardized periapical radiographs were taken 1 week after implant placement (TP), 1 week (TC) and 1-1.5 year (T1) after crown delivery, and 10 years after implant placement (T10). Pocket depth (PD) and bleeding on probing were registered during controls (TC - T10).

RESULTS

Two Ea and one De implants failed to osseointegrate. Seven patients (4 Ea, 1 De, and 2 La) were not available at T10 . No significant differences were found among groups regarding implant survival or radiographic peri-implant marginal bone levels (Ea: 1.15 ± 0.77; De: 1.53 ± 1.06; La: 1.42 ± 1.07) at T10 . Similarly, no differences were observed among groups in the number of implants with PD ≥ 5 mm (Ea: 29%; De: 35%; La: 44%) or the average depth of the sites with PD ≥ 5 mm (Ea: 5.4 ± 0.7; De: 6.1 ± 1.4; La: 5.4 ± 0.5) at T10 . Peri-implant mucositis was found in 70% of the cases; peri-implantitis was diagnosed only in two implants (1 De, 1 La) corresponding to 4.3%.

CONCLUSION

Single-tooth implants placed early or delayed after tooth extraction show high survival rates and limited peri-implant marginal bone resorption or biological complications, similar to what is observed with implants placed according to the conventional (late) protocol.

A review on alveolar ridge preservation following tooth extraction

CONTEXT

The question that clinicians face is whether the use of bone replacement grafts and/or barrier membranes enhance their ability to provide for the future placement of a dental implant or to maximize ridge dimensions following the extraction of a tooth versus no additional treatments.

EVIDENCE ACQUISITION

The evidence was obtained by search of Entrez PubMed and manual search of The International Journal of Oral and Maxillofacial Implants, The International Journal of Periodontics & Restorative Dentistry, Clinical Oral Implant Research, The Journal of Periodontology, The Journal of Clinical Periodontology, and The Compendium of Continuing Education in Dentistry. Key search words included Guided Bone Regeneration, Dental Extraction, Tooth Extraction, Bone Replacement Graft, Alveolar Ridge. The years of search included from January 2011 through February 2012.

EVIDENCE SYNTHESIS

The recurring theme was that there was considerable heterogeneity to study designs, time periods, and methods of evaluation. This created great difficulty in trying to answer with good high-quality evidence questions about the techniques and materials to be used for maximizing regeneration at the time of tooth extraction or in which situations this ought to be used.

CONCLUSIONS

There appears to be consensus from the reviewed literature supporting ridge preservation techniques as a whole. Multiple studies demonstrated less ridge resorption occurring when alveolar ridge preservation procedures were used versus the placement of no graft material in fresh alveolar sockets. The analysis did not show any grafting materials demonstrating a clear benefit over any others or that a barrier membrane is necessary. The evidence is also too premature about whether socket preservation efforts require primary closure. In the emerging area of growth factors, there is no high-quality evidence to either support or refute their use.

BACKGROUND

Tooth extraction is one of the most widely performed procedures in dentistry today and it has been historically well documented that this procedure may induce significant dimensional changes of the alveolar ridge. The dilemma that clinicians face is how to manage tooth extractions to provide for the future placement of a dental implant or to maximize ridge dimensions for the fabrication of a fixed or removable prosthesis. If performed inadequately, the resulting deformity can be a considerable obstacle to the esthetic, phonetic, and functional results that both our patients and we clinicians expect at this current time.

Postextraction alveolar ridge preservation: biological basis and treatments

Following tooth extraction, the alveolar ridge undergoes an inevitable remodeling process that influences implant therapy of the edentulous area. Socket grafting is a commonly adopted therapy for the preservation of alveolar bone structures in combination or not with immediate implant placement although the biological bases lying behind this treatment modality are not fully understood and often misinterpreted. This review is intended to clarify the literature support to socket grafting in order to provide practitioners with valid tools to make a conscious decision of when and why to recommend this therapy.

Evidence-based knowledge on the biology and treatment of extraction sockets

OBJECTIVES

The fresh extraction socket in the alveolar ridge represents a special challenge in everyday clinical practice. Maintenance of the hard and soft tissue envelope and a stable ridge volume were considered important aims to allow simplifying subsequent treatments and optimizing their outcomes in particular, when implants are planned to be placed.

MATERIAL AND METHODS

Prior to the consensus meeting four comprehensive systematic reviews were written on two topics regarding ridge alteration and ridge preservation following tooth extraction and implant placement following tooth extraction. During the conference these manuscripts were discussed and accepted thereafter. Finally, consensus statements and recommendations were formulated.

RESULTS

The systematic reviews demonstrated that the alveolar ridge undergoes a mean horizontal reduction in width of 3.8 mm and a mean vertical reduction in height of 1.24 mm within 6 months after tooth extraction. The techniques aimed at ridge preservation encompassed two different approaches: i) maintaining the ridge profile, ii) enlarging the ridge profile. Regarding timing of implant placement the literature showed that immediate implant placement leads to high implant survival rates. This procedure is primarily recommended in premolar sites with low esthetic importance and favorable anatomy. In the esthetic zone, however, a high risk for mucosal recession was reported. Hence, it should only be used in stringently selected situations with lower risks and only by experienced clinicians. In molar sites a high need for soft and hard tissue augmentation was identified.

CONCLUSIONS

Future research should clearly identify the clinical and patient benefits resulting from ridge preservation compared with traditional procedures. In addition, future research should also aim at better identifying parameters critical for positive treatment outcomes with immediate implants. The result of this procedure should be compared to early and late implant placement.

Post-Extractive Implants: Outcome of 40 Cases

In the last two decades, several investigators have reported immediate placement of dental implants into extraction sockets achieving excellent results with a two-stage surgical procedure. Recently immediate loading has become an emerging technique as it has been documented to be a successful and time saving procedure. As regard the possibility of immediate/early loading of implants placed in fresh extraction sockets few reports are available. In addition they are based on limited series with short follow-up. Thus we decided to perform a retrospective study on a series of post-extractive implants. A total of 40 two-piece implants (FMD srl, Rome, Italy) were inserted in post extractive sockets, 22 in females and 18 in males. The median age was 52 ± 11 (min-max 24–69 years). Twenty-one implants were inserted in upper jaw and 19 in mandible. Fixtures replaced 7 incisors, 3 cuspids, 12 premolars and 18 molars. Implant' length was x ≤ 10 mm, 10,30 ≤ x ≤ 12.30, equal to 13 mm and x ≥14 mm in 6,14,9, and 11 cases, respectively. Implant' diameter was narrower than 3.5 mm, equal to 3.8 mm and wider than 4.0 mm in 1,7, and 32 cases, respectively. There were 28, 2 and 10 Elisir, I-fix, and Shiner implant types, respectively. No implant on single tooth rehabilitations, was lost, survival rate = 100%. Then peri-implant bone resorption (i.e. delta IAJ) was used to investigate SCR. Seven fixtures have a crestal bone resorption greater than 1.5 mm (SCR = 82.5%). Statistical analysis demonstrated that there was a difference between surgeons (p= 0.005). In conclusion FMD implants are reliable devices for oral rehabilitation with a very high SCR and SVR.