Ridge preservation following tooth extraction using a polylactide and polyglycolide sponge as space filler: a clinical and histological study in humans.

After a tooth extraction, the height of the buccal wall tends to decrease. The literature indicates that regenerative techniques (guided bone regenerative [GBR] techniques) have succeeded in improving the bone levels. Therefore, this experiment set out to compare the physiological bone remodelling in Beagle dog models after implant placement in a fresh extraction socket, with and without the application of regenerative procedure. Five dogs were used in this study. Test and control sites were randomly selected. The experimental teeth (fourth pre-molar and first molar) were hemi-sected removing the distal roots and placing implants. Porcine bone was placed to fill the gap around the implant on the test sites and a reabsorbable membrane was used to cover the area. The dogs were put down at different times (2 weeks, 1 month and 3 months). The measurements were taken immediately and at 2, 4, 12 weeks after implant placement. Student's test for paired data was used to compare the means of the clinical measurements. At 2 weeks: On the control sites, few signs of resorption were detected at the first molar only, while at the test sites bone levels were placed at the implant shoulder or above. At 4 weeks: On the control site, slight bone remodelling was observed, while on the test site minor signs of resorption or an increase of bone levels were detected. At 12 weeks: The alveolar crest on the control sites showed various degrees of remodelling. On the test sites stable bone levels or an increase of bone crest was observed. With the limits of this study, the findings showed that GBR techniques were able to limit resorption of the alveolar crest after tooth extraction. A pattern of bone remodelling after tooth extraction and implant placement was observed in the control sites (no GBR) as well as in test sites (GBR), and although the exact cause of this is unclear, surgical trauma could play a role. Further studies are necessary to confirm these results and to clarify the precise causes of bone remodelling in fresh extraction sockets.

Following tooth extraction, bone resorption is especially severe in cases complicated with buccal dehiscence bone defects. To minimize this, various bone graft materials have been used for alveolar ridge preservation. This study aimed to evaluate additional effects of the concomitant use of recombinant human fibroblast growth factor-2 (rhFGF-2) with β-tricalcium phosphate (β-TCP) on ridge preservation in a dehiscence defect model after tooth extraction in dogs. The maxillary first premolars of six beagle dogs were extracted and dehiscence defects of 4×4×5mm (mesio-distal width×bucco-palatal width×depth) were created. Bilateral defects were filled with β-TCP combined with 0.3% (w/v) rhFGF-2 (test sites) or the scaffold alone (control sites). Twelve weeks post-surgery, histologic and histometric evaluations were performed. Morphological measurements using micro-computed tomography revealed a significantly greater bone volume at the test sites (48.9±9.06 mm3 ) than at the control sites (38.8±7.24 mm3 ). Horizontal widths of the alveolar ridge at the coronal and middle position at the test sites (2.18±0.71mm, 2.93±0.53mm) were significantly greater than those at the control sites (1.47±0.41mm, 2.36±0.45mm, respectively). Regarding the histological parameters, the occupation rate of mineralized bone in the original defects was slightly higher at the test sites (44.07±10.19%) than that at the control site (41.15±6.56%). These results indicate that the adjunct use of rhFGF-2 with β-TCP is effective for alveolar ridge preservation in fresh extraction sockets with dehiscence defects.

Reduction in alveolar ridge volume is a direct consequence of tooth extraction. Tunnel β-tricalcium phosphate (β-TCP) blocks were manufactured from randomly organized tunnel-shaped β-TCP ceramic. Efficacy of these blocks compared to extraction alone for alveolar ridge preservation after tooth extraction with buccal bone deficiency was evaluated. Maxillary first premolars of six beagle dogs were extracted after removing the buccal bone, and bone defects of 4 × 4 × 5 mm (mesio-distal width × bucco-palatal width × depth) were created. Fresh extraction sockets with buccal bone defects were filled with tunnel β-TCP blocks at test sites. Two months after the operation, histologic and histometric evaluations were performed. Regarding histologic sections, coronal and middle horizontal widths of the alveolar ridge were significantly greater at test sites (3.2 ± 0.5 and 3.6 ± 0.4 mm, respectively) than at control sites (1.2 ± 0.3 and 2.0 ± 0.6 mm, respectively). The amount of woven bone was significantly greater at test sites (62.4% ± 7.9%) than at control sites (26.8% ± 5.3%), although that of connective tissue and bone marrow was significantly greater at control sites (38.1% ± 6.2% and 16.0% ± 6.9%, respectively) than at test sites (10.7% ± 5.7% and 4.1% ± 2.2%, respectively). Regarding basic multicellular units, no statistically significant difference was found between the test and control sites (0.5% ± 0.1% and 0.6% ± 0.1%, respectively). Tunnel β-TCP blocks represent an effective bone-graft material for alveolar ridge preservation in fresh extraction sockets with buccal bone defects.

Tooth extraction triggers alveolar ridge resorption, and when this resorption is extensive, it can complicate subsequent reconstructive procedures that use dental implants. Clinical data demonstrate that the most significant dimensional changes in the ridge occur soon after tooth extraction. Here, we sought to understand whether a correlation existed between the rate at which an extraction socket heals and the extent of alveolar ridge resorption. Maxillary molars were extracted from young and osteoporotic rodents, and quantitative micro–computed tomographic imaging, histology, and immunohistochemistry were used to simultaneously follow socket repair and alveolar ridge resorption. Extraction sockets rapidly filled with new bone via the proliferation and differentiation of Wnt-responsive osteoprogenitor cells and their progeny. At the same time that new bone was being deposited in the socket, tartrate-resistant acid phosphatase–expressing osteoclasts were resorbing the ridge. Significantly faster socket repair in young animals was associated with significantly more Wnt-responsive osteoprogenitor cells and their progeny as compared with osteoporotic animals. Delivery of WNT3A to the extraction sockets of osteoporotic animals restored the number of Wnt-responsive cells and their progeny back to levels seen in young healthy animals and accelerated socket repair in osteoporotic animals back to rates seen in the young. In cases where the extraction socket was treated with WNT3A, alveolar ridge resorption was significantly reduced. These data demonstrate a causal link between enhancing socket repair via WNT3A and preserving alveolar ridge dimensions following tooth extraction.

Aims: To evaluate the effect of collagen fibers that placed immediately in alveolar bone socket after tooth extraction on homeostasis, quality and quantity of bone formation and their complications.Materials and Methods: The study group consists of 10 patients who attend to Oral and Maxillofacial Department in Dentistry College of Mosul University. The patients complained from chronic periapical lesions in badly carious two teeth in the same jaw (upper or lower jaw) that indicated for teeth extraction. Every patient underwent teeth extraction after receive local anesthesia with vasoconstriction, immediately after teeth extraction we put highly concentrated collagen material PARASORB® Dental Cones: 1 collagen cone contains 22.4 mg native equine collagen fibrils (RESORBA Wundversorgung GmbH & Co. KG, Germany) in one tooth socket (study site) and leave the other tooth socket to fill with blood clot (control group),Follow up the patients clinically and radiographically were done immediately after placement the material followed by different interval depending on the using test until six weeks. Results: The clinical assessment showed there is high significant difference (p-value ≤ 0.01) in the haemostatic condition between the study and control sites while there is no significant difference (p-value >0.05) in infection involvement of both study and control sites. The radiographical assessment of bone formation showed significant difference in bone density between study sites and control sites after two weeks (p-value ≤0.05), and high significant difference at fourth and sixth weeks (p-value ≤0.001). Conclusions: The collagen fibril play important role in control of hemorrhage following tooth extraction, prevent infection at the surgical site, promote granulation tissue formation and wound healing, reduce alveolar ridge resorption after tooth extraction (socket preservation) and enhance bone formation.

This pilot randomised controlled clinical trial aimed to evaluate the feasibility and effectiveness of using a polycaprolactone (PCL) scaffold in fresh extraction sockets for ridge preservation. The hypothesis was that the insertion of a 3D bioresorbable PCL scaffold in fresh extraction sockets allowed for normal bone healing and better maintenance of ridge dimensions after 6 months as compared to extraction sockets without the scaffold. Thirteen patients were randomised to either the test group (N = 6) where a PCL scaffold was inserted in the tooth socket after extraction or the control group (N = 7) where no space filler was used. Alveolar ridge height and width measurements were made at baseline and 6 months post-extraction, for the evaluation of bone resorption. At 6 months, a core of bone was trephined out from the healed ridge for microcomputed tomographic (micro CT) and histological analyses, immediately before Stage I dental implant surgery. Stage II dental implant surgery was performed 4-6 months later. There was less vertical ridge resorption in the test group compared to the control group, and the difference was statistically significant in the mesio-buccal aspect (P = 0.008). Micro CT and histological observations showed mainly mineralised bone formation in both groups, except for one specimen in the test group. The insertion of a 3D bioresorbable PCL scaffold in fresh extraction sockets allowed for normal bone healing, and there was better maintenance of ridge height after 6 months as compared to extraction sockets without the scaffold.

PurposePrevious studies have solely focused on fresh extraction sockets, whereas in clinical settings, alveolar sockets are commonly associated with chronic inflammation. Because the extent of tissue destruction varies depending on the origin and the severity of inflammation, infected alveolar sockets may display various configurations of their remaining soft and hard tissues following tooth extraction. The aim of this study was to classify infected alveolar sockets and to provide the appropriate treatment approaches.MethodsA proposed classification of extraction sockets with chronic inflammation was developed based upon the morphology of the bone defect and soft tissue at the time of tooth extraction. The prevalence of each type of the suggested classification was determined retrospectively in a cohort of patients who underwent, between 2011 and 2015, immediate bone grafting procedures (ridge preservation/augmentation) after tooth extractions at Seoul National University Dental Hospital.ResultsThe extraction sockets were classified into 5 types: type I, type II, type III, type IV (A & B), and type V. In this system, the severity of bone and soft tissue breakdown increases from type I to type V, while the reconstruction potential and treatment predictability decrease according to the same sequence of socket types. The retrospective screening of the included extraction sites revealed that most of the sockets assigned to ridge preservation displayed features of type IV (86.87%).ConclusionsThe present article classified different types of commonly observed infected sockets based on diverse levels of ridge destruction. Type IV sockets, featuring an advanced breakdown of alveolar bone, appear to be more frequent than the other socket types.

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. 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. 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. 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.

The aim of the present study was to assess the efficacy of a ready-to-use injectable bone substitute on the prevention of alveolar ridge resorption after tooth extraction. Maxillary and mandibular premolars were extracted from 3 Beagle dogs with preservation of alveolar bone. Thereafter, distal sockets were filled with an injectable bone substitute (IBS), obtained by combining a polymer solution and granules of a biphasic calcium phosphate (BCP) ceramic. As a control, the mesial sockets were left unfilled. After a 3 months healing period, specimens were removed and prepared for histomorphometric evaluation with image analysis. Histomorphometric study allowed to measure the mean and the maximal heights of alveolar crest modifications. Results always showed an alveolar bone resorption in unfilled sockets. Resorption in filled maxillary sites was significantly lower than in control sites. Interestingly, an alveolar ridge augmentation was measured in mandibular filled sockets including 30% of newly-formed bone. It was concluded that an injectable bone substitute composed of a polymeric carrier and calcium phosphate can significantly increase alveolar ridge preservation after tooth extraction.

Focused Clinical Question: How should the extraction socket be managed after tooth removal?Summary: Resorptive changes that take place after tooth extraction can result in a significant reduction in alveolar ridge width and height. This may create a problem for proper implant placement and fabrication of esthetic restorations. Ridge preservation has been shown to be effective in decreasing alveolar bone resorption after tooth removal. During ridge preservation, the extraction socket is filled with graft material, and a barrier is generally used to contain the graft. Flap reflection is usually not recommended if the socket walls are intact and the ridge width is sufficient after tooth removal. However, if significant breakdown of the buccal bony plate is present, mucoperiosteal flap elevation may be required to allow proper placement of the bone graft and membrane. Different types of bone grafts (autograft, allograft, and xenograft) and barrier membranes (resorbable and non‐resorbable) have been evaluated in clinical studies. They all are shown to be effective regardless of the material or technique used.Conclusions: Ridge preservation is an effective procedure for minimizing horizontal and vertical alveolar ridge resorption after tooth extraction. Current evidence does not support one technique as being superior to another. The selection of the technique to be used should be based on the clinical situation.

Background: Damage to bone tissue resulting from tooth extraction will cause alveolar bone resorption. Therefore, a material for preserving alveolar sockets capable of maintaining bone is required. Hydroxyapatite Gypsum Puger (HAGP) is a bio-ceramic material that can be used as an alternative material for alveolar socket preservation. The porous and rough surface of HAGP renders it a good medium for osteoblast cells to penetrate and attach themselves to. In general, bone mass is regulated through a remodeling process consisting of two phases, namely; bone formation by osteoblasts and bone resorption by osteoclasts. Purpose: This research aims to identify the effects of HAGP scaffold application on the number of osteoblasts and osteoclasts, as well as on the width of trabecular bone area in the alveolar sockets of rats. Methods: This research used Posttest Only Control Group Design. There were three research groups, namely: a group with 2.5% HAGP scaffold, a group with 5% HAGP scaffold and a group with 10% HAGP scaffold. The number of samples in each group was six. HAGP scaffold at concentrations of 2.5%, 5% and 10% was then mixed with PEG (Polyethylene Glycol). The Wistar rats were anesthetized intra-muscularly with 100 mg/ml of ketamine and 20 mg/ml of xylazine base at a ratio of 1:1 with a dose of 0.08-0.2 ml/kgBB. Extraction of the left mandibular incisor was performed before 0.1 ml preservation of HAGP scaffold + PEG material was introduced into the extraction sockets and suturing was performed. 7 days after preparation of the rat bone tissue, an Hematoxilin Eosin staining process was conducted in order that observation under a microscope could be performed. Results: There were significant differences in both the number of osteoclasts and osteoblasts between the 2.5% HAGP group, the 5% HAGP group and the 10% HAGP group (p = 0.000). Similarly, significant differences in the width of the trabecular bone area existed between the 5% HAGP group and the 10% HAGP group, as well as between the 2.5% HAGP group and the 10% HAGP group (p=0.000). In contrast, there was no significant difference in the width of the trabecular bone area between the 2.5% HAGP group and the 5% HAGP group. Conclusion: The application of HAGP scaffold can reduce osteoclasts, increase osteoblasts and extend the trabecular area in the alveolar bone sockets of rats.

To evaluate the influence of the presence or absence of adjacent teeth on the level of the mesial and distal alveolar bony crest following healing at sites where implants were installed immediately into extraction sockets. Six Labrador dogs were used. In the right side of the mandible, full-thickness flaps were elevated, and the second, third, and fourth premolars and first molars were extracted. In the left side of the mandible, endodontic treatments of the mesial roots of the third and fourth premolars as well as of the first molars were performed. Full-thickness flaps were elevated, the teeth were hemi-sected, and the distal roots were removed. The second premolars were extracted as well. Subsequently, implants were bilaterally installed with the implant shoulder flush with the buccal bony crest. Implants were placed in the center of the alveoli, but at the fourth premolars, they were placed toward the lingual bony plate of the alveoli. After 3months of healing, the animals were euthanized and histological sections of the sites prepared. Larger bony crest resorption was observed at the test compared with the control sites, both at the bucco-lingual and mesio-distal aspects. The differences between test and controls for the coronal level of osseointegration were smaller than those for resorption. When data from all mesial and distal sites facing an adjacent tooth were collapsed and compared with those opposing an edentulous zone, lower bony crest resorption and deeper residual marginal defects were found at the sites with neighboring teeth. The extraction of teeth adjacent to a socket into which implants were installed immediately after tooth extraction caused more alveolar bone resorption both for the bucco-lingual and at the mesio-distal aspects compared with sites adjacent to a maintained tooth.

To study the influence on the healing of soft and hard peri-implant tissues when implants of different sizes and configurations were installed into sockets immediately after tooth extraction. Transmucosal cylindrical implants, 3.3mm in diameter in the control sites, and conical 5mm in diameter in the test sites, were installed into the distal socket of the fourth mandibular premolars in dogs immediately after tooth extraction. After 4months, the hard and soft tissue healing was evaluated histologically. All implants were integrated in mineralized mature bone. Both at the test and control sites, the alveolar crest underwent resorption. The buccal bony surface at the implant test sites (conical; 3.8mm) was more resorbed compared with the control sites (cylindrical; 1.6mm). The soft tissue dimensions were similar in both groups. However, in relation to the implant shoulder, the peri-implant mucosa was located more apically at the test compared with the control sites. The present study confirmed that the distance between the implant surface and the outer contour of the buccal alveolar bony crest influenced the degree of resorption of the buccal bone plate. Consequently, in relation to the implant shoulder, the peri-implant mucosa will be established at a more apical level, if the distance between the implant surface and the outer contour of the alveolar crest is small.

'Immediate' implants are placed in dental sockets just after tooth extraction. 'Immediate-delayed' implants are those implants inserted after weeks up to about a couple of months to allow for soft tissue healing. 'Delayed' implants are those placed thereafter in partially or completely healed bone. The potential advantages of immediate implants are that treatment time can be shortened and that bone volumes might be partially maintained thus possibly providing good aesthetic results. The potential disadvantages are an increased risk of infection and failures. After implant placement in postextractive sites, gaps can be present between the implant and the bony walls. It is possible to fill these gaps and to augment bone simultaneously to implant placement. There are many techniques to achieve this but it is unclear when augmentation is needed and which could be the best augmentation technique. To evaluate success, complications, aesthetics and patient satisfaction between 'immediate', 'immediate-delayed' and 'delayed' implants.To evaluate whether and when augmentation procedures are necessary and which is the most effective technique. The Cochrane Oral Health Group's Trials Register (to 2 June 2010), CENTRAL (The Cochrane Library 2010, Issue 2), MEDLINE via OVID (1950 - 2 June 2010) and EMBASE via OVID (1980 - 2 June 2010) were searched. Several dental journals were handsearched. Randomised controlled trials (RCTs) comparing immediate, immediate-delayed, and delayed implants, or comparing various bone augmentation procedures around the inserted implants, reporting the outcome of the interventions to at least 1 year after functional loading. Screening of eligible studies, assessment of the methodological quality of the trials and data extraction were conducted independently and in duplicate. Trial authors were contacted for any missing information. Results were expressed as random-effects models using mean differences for continuous outcomes and risk ratios (RR) for dichotomous outcomes with 95% confidence intervals (CIs). The statistical unit of the analysis was the patient. Fourteen eligible RCTs were identified but only seven trials could be included. Four RCTs evaluated implant placement timing. Two RCTs compared immediate versus delayed implants in 126 patients and found no statistically significant differences. One RCT compared immediate-delayed versus delayed implants in 46 patients. After 2 years patients in the immediate-delayed group perceived the time to functional loading significantly shorter, were more satisfied and independent blinded assessor judged the level of the perimplant marginal mucosa in relation to that of the adjacent teeth as more appropriate (RR = 1.68; 95% CI 1.04 to 2.72). These differences disappeared 5 years after loading but significantly more complications occurred in the immediate-delayed group (RR = 4.20; 95% CI 1.01 to 17.43). One RCT compared immediate with immediately delayed implants in 16 patients for 2 years and found no differences. Three RCTs evaluated different techniques of bone grafting for implants immediately placed in extraction sockets. No statistically significant difference was observed when evaluating whether autogenous bone is needed in postextractive sites (1 trial with 26 patients) or which was the most effective augmentation technique (2 trials with 56 patients). There is insufficient evidence to determine possible advantages or disadvantages of immediate, immediate-delayed or delayed implants, therefore these preliminary conclusions are based on few underpowered trials often judged to be at high risk of bias. There is a suggestion that immediate and immediate-delayed implants 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. There is not enough reliable evidence supporting or refuting the need for augmentation procedures at immediate implants placed in fresh extraction sockets or whether any of the augmentation techniques is superior to the others.

Background: ‘Immediate’ implants are placed in dental sockets just after tooth extraction. ‘Immediate‐delayed’ implants are those implants inserted after weeks up to about a couple of months to allow for soft tissue healing. ‘Delayed’ implants are those placed thereafter in partially or completely healed bone. The potential advantages of immediate implants are that treatment time can be shortened and that bone volumes might be partially maintained thus possibly providing good aesthetic results. The potential disadvantages are an increased risk of infection and failures. After implant placement in postextractive sites, gaps can be present between the implant and the bony walls. It is possible to fill these gaps and to augment bone simultaneously to implant placement. There are many techniques to achieve this but it is unclear when augmentation is needed and which could be the best augmentation technique.Objectives: To evaluate success, complications, aesthetics and patient satisfaction between ‘immediate’, ‘immediate‐delayed’ and ‘delayed’ implants. To evaluate whether and when augmentation procedures are necessary and which is the most effective technique.Search strategy: The Cochrane Oral Health Group’s Trials Register (to 2 June 2010), CENTRAL (The Cochrane Library 2010, Issue 2), MEDLINE via OVID (1950 – 2 June 2010) and EMBASE via OVID (1980 – 2 June 2010) were searched. Several dental journals were handsearched.Selection criteria: Randomized controlled trials (RCTs) comparing immediate, immediate‐delayed and delayed implants, or comparing various bone augmentation procedures around the inserted implants, reporting the outcome of the interventions to at least 1 year after functional loading.Data collection and analysis: Screening of eligible studies, assessment of the methodological quality of the trials and data extraction were conducted independently and in duplicate. Trial authors were contacted for any missing information. Results were expressed as random‐effects models using mean differences for continuous outcomes and risk ratios (RR) for dichotomous outcomes with 95% confidence intervals (CIs). The statistical unit of the analysis was the patient.Main results: Fourteen eligible RCTs were identified but only 7 trials could be included. Four RCTs evaluated implant placement timing. Two RCTs compared immediate versus delayed implants in 126 patients and found no statistically significant differences. One RCT compared immediate‐delayed versus delayed implants in 46 patients. After 2 years patients in the immediate‐delayed group perceived the time to functional loading significantly shorter, were more satisfied and an independent blinded assessor judged the level of the peri‐implant marginal mucosa in relation to that of the adjacent teeth as more appropriate (RR = 1.68; 95% CI 1.04 to 2.72). These differences disappeared 5 years after loading but significantly more complications occurred in the immediate‐delayed group (RR = 4.20; 95% CI 1.01 to 17.43). One RCT compared immediate with immediately delayed implants in 16 patients for 2 years and found no differences. Three RCTs evaluated different techniques of bone grafting for implants immediately placed in extraction sockets. No statistically significant difference was observed when evaluating whether autogenous bone is needed in postextractive sites (1 trial with 26 patients) or which was the most effective augmentation technique (2 trials with 56 patients).Authors’ conclusions: There is insufficient evidence to determine possible advantages or disadvantages of immediate, immediate‐delayed or delayed implants, therefore these preliminary conclusions are based on a few underpowered trials often judged to be at high risk of bias. There is a suggestion that immediate and immediate‐delayed implants 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. There is not enough reliable evidence supporting or refuting the need for augmentation procedures at immediate implants placed in fresh extraction sockets or whether any of the augmentation techniques are superior to the others.