Evaluation of healing at molar extraction sites with ridge preservation using a non-resorbable dense polytetrafluoroethylene membrane: A four-arm cohort prospective study

Objectives

To examine ridge dimensional changes and histologic parameters of healing when ridge preservation (RP) was performed at molar sites using dense polytetrafluoroethylene (dPTFE) membrane alone, without a bone graft.

Material and Methods

Eighteen patients had molar extraction and RP using dPTFE membrane alone. Ridge dimensions were measured using two standardized cone beam computerized tomography (CBCT) scans taken within 72 h and 3 months following extraction. Following a 3‐month healing period, an implant osteotomy was prepared using a trephine drill and bone cores were collected for histological analysis. Four‐arm analyses were performed using data from three previously published study arms of the same research group.

Results

There was a significant change in the buccal ridge height between the four groups at all aspects of the socket. Alveolar ridge width reduction at 3 mm from crest for all aspects (mesial, midpoint, distal) of the socket showed statistically significant difference for dPTFE alone group compared to the other three groups. Percentage of vital bone formation (62.10%) was significantly greater in dPTFE alone group compared to the other groups.

Conclusions

RP using dPTFE membrane alone in molar sites with intact socket walls showed successful outcomes in maintaining ridge dimensions and in histologic wound healing.

Impact of different surgical protocols on dimensional changes of free soft tissue autografts: A randomized controlled trial

BACKGROUND

To determine if there is a difference in the amount of shrinkage during healing of free soft tissue autografts (FSTAs) using different surgical techniques-suturing the vestibular flap margin apically to the base of the recipient bed versus leaving the flap margin free and unsutured.

METHODS

Twenty-eight patients with mucogingival defects requiring FSTAs were recruited and enrolled in the study. Patients were randomized into test and control groups (14 per group) and received ≥1 FSTAs on non-molar mandibular teeth. In the test group the mucosal flap margin was sutured apically to the periosteum at the base of the graft; whereas, the mucosal flap margin in the control group was left free. Graft dimensional measurements were taken at time of surgery, then at 1, 3, and 6 months post-surgery.

RESULTS

Thirty-five grafts were performed (15 test, 20 control). All FSTAs experienced vertical shrinkage after 6 months, but there was no significant difference (P = 0.51) in the mean amount of shrinkage after 6 months between the test (23.20% ± 20.88%) and control (21.10% ± 21.88%) groups. There was significantly greater horizontal shrinkage in the test (loss of 7.59% ± 10.20%) compared with the control (small gain of 0.32% ± 4.20%) group (P = 0.01).

CONCLUSIONS

The findings suggest that there is similar vertical shrinkage when performing FSTA surgery when the mucosal flap margin is left free and unsutured when compared with leaving the flap margin free.

Peri-implant diseases and conditions: Consensus report of workgroup 4 of the 2017 World Workshop on the Classification of Periodontal and Peri-Implant Diseases and Conditions

A classification for peri-implant diseases and conditions was presented. Focused questions on the characteristics of peri-implant health, peri-implant mucositis, peri-implantitis, and soft- and hard-tissue deficiencies were addressed. Peri-implant health is characterized by the absence of erythema, bleeding on probing, swelling, and suppuration. It is not possible to define a range of probing depths compatible with health; Peri-implant health can exist around implants with reduced bone support. The main clinical characteristic of peri-implant mucositis is bleeding on gentle probing. Erythema, swelling, and/or suppuration may also be present. An increase in probing depth is often observed in the presence of peri-implant mucositis due to swelling or decrease in probing resistance. There is strong evidence from animal and human experimental studies that plaque is the etiological factor for peri-implant mucositis. Peri-implantitis is a plaque-associated pathological condition occurring in tissues around dental implants, characterized by inflammation in the peri-implant mucosa and subsequent progressive loss of supporting bone. Peri-implantitis sites exhibit clinical signs of inflammation, bleeding on probing, and/or suppuration, increased probing depths and/or recession of the mucosal margin in addition to radiographic bone loss. The evidence is equivocal regarding the effect of keratinized mucosa on the long-term health of the peri-implant tissue. It appears, however, that keratinized mucosa may have advantages regarding patient comfort and ease of plaque removal. Case definitions in day-to-day clinical practice and in epidemiological or disease-surveillance studies for peri-implant health, peri-implant mucositis, and peri-implantitis were introduced. The proposed case definitions should be viewed within the context that there is no generic implant and that there are numerous implant designs with different surface characteristics, surgical and loading protocols. It is recommended that the clinician obtain baseline radiographic and probing measurements following the completion of the implant-supported prosthesis.

Transferring subgingival contours around implants and the intaglio surface of the pontic to definitive digital casts by using an intraoral scanner: A technique

The accurate transfer of the subgingival contours of implant-supported restorations and pontics is essential for providing the dental technician with the necessary information to fabricate an optimal definitive fixed dental prosthesis. However, once the interim restoration is removed to make an impression, the subgingival tissue, which is no longer physically supported, tends to collapse. This digital intraoral and extraoral scanning technique offers a way to transfer the subgingival contours and intaglio surface of the interim restoration to the definitive restoration. In addition, this technique can reduce clinical and laboratory time, as well as the necessity of storing gypsum casts.

Immediate loading vs. early/conventional loading of immediately placed implants in partially edentulous patients from the patients' perspective: A systematic review

OBJECTIVES

This systematic review aimed at answering the following PICO question: In patients receiving immediate (Type 1) implant placement, how does immediate compare to early or conventional loading in terms of Patient-Reported Outcome Measures (PROMs)?

MATERIAL AND METHODS

Following search strategy development, the OVID, PubMed, EMBASE, and Cochrane Database of Systematic Reviews databases were search for the relevant literature. All levels of evidence including randomized controlled trials, prospective and retrospective cohort studies, and case series of at least five patients were considered for possible inclusion. An additional manual search was performed by screening the reference lists of relevant studies and systematic reviews published up to May 2017. The intervention considered was the placement of immediate implant. Study selection and data extraction were performed independently by two reviewers.

RESULTS

The search yielded a list of 1,102 references, of which nine were included in this systematic review. The limited number of studies included and the heterogeneity of the data identified prevented the performance of a meta-analysis. Three studies, one of which was a randomized controlled trial, allowed the extraction of comparative data specific to the aim of the present systematic review. The remaining studies allowed only data extraction for one single treatment modality and were viewed as single cohort studies. Overall, irrespective of the PROMs chosen, patients' satisfaction was overall high with little difference between the two loading protocols. Moreover, studies indicated a positive impact on oral health-related quality of life following immediate implant placement and loading.

CONCLUSIONS

Within the limitations of the present systematic review, immediate implant placement and loading in single tooth edentulous space seems to be a well-accepted treatment modality from the patients' perspective and is worthy of consideration in clinical practice. However, the paucity of comparative data limits any definitive conclusions as to which loading protocol; immediate or early/conventional, should be given preference based on PROMs.

Peri-implant diseases and conditions: Consensus report of workgroup 4 of the 2017 World Workshop on the Classification of Periodontal and Peri-Implant Diseases and Conditions

A classification for peri-implant diseases and conditions was presented. Focused questions on the characteristics of peri-implant health, peri-implant mucositis, peri-implantitis, and soft- and hard-tissue deficiencies were addressed. Peri-implant health is characterized by the absence of erythema, bleeding on probing, swelling, and suppuration. It is not possible to define a range of probing depths compatible with health; Peri-implant health can exist around implants with reduced bone support. The main clinical characteristic of peri-implant mucositis is bleeding on gentle probing. Erythema, swelling, and/or suppuration may also be present. An increase in probing depth is often observed in the presence of peri-implant mucositis due to swelling or decrease in probing resistance. There is strong evidence from animal and human experimental studies that plaque is the etiological factor for peri-implant mucositis. Peri-implantitis is a plaque-associated pathological condition occurring in tissues around dental implants, characterized by inflammation in the peri-implant mucosa and subsequent progressive loss of supporting bone. Peri-implantitis sites exhibit clinical signs of inflammation, bleeding on probing, and/or suppuration, increased probing depths and/or recession of the mucosal margin in addition to radiographic bone loss. The evidence is equivocal regarding the effect of keratinized mucosa on the long-term health of the peri-implant tissue. It appears, however, that keratinized mucosa may have advantages regarding patient comfort and ease of plaque removal. Case definitions in day-to-day clinical practice and in epidemiological or disease-surveillance studies for peri-implant health, peri-implant mucositis, and peri-implantitis were introduced. The proposed case definitions should be viewed within the context that there is no generic implant and that there are numerous implant designs with different surface characteristics, surgical and loading protocols. It is recommended that the clinician obtain baseline radiographic and probing measurements following the completion of the implant-supported prosthesis.

A systematic review and meta-analysis of the survival rate of implants placed in previously failed sites

The aim of this study was to conduct a systematic review and meta-analysis to assess the clinical outcomes of dental implants placed in previously early and late implant failed sites. An electronic literature search was conducted in several databases for articles published up to February 2018. Human clinical trials that received at least one implant in a previously failed site were included. Hence, the PICO question that was aimed to be addressed was: Do patients undergoing implant replacement (second and third attempts) in previous failed sites have survival rates similar to implants placed at first attempts? A random effects model was used to calculate survival weighted means and corresponding 95% Confidence Intervals (CI) among studies. Eleven studies of low to moderate methodological quality were included in this review. Implants placed in sites with history of one and two implant failures had a weighted survival rate (SR) of 88.7% (95%CI 81.7-93.3) and 67.1% (95%CI 51.1-79.9), respectively. Implants placed in sites with a previous early failure revealed a weighted SR of 91.8% (95%CI 85.1-95.6). First implants presented higher SR than implants placed in sites with one or two previous implant failures. In contrast, implants placed in sites with one and two implant failures had similar SR. Within its limitations, this review suggests that replacement implants have moderate SR. Larger prospective studies with well-defined criteria for early and late implant failure are necessary to confirm and expand on these results.

Osseous Healing Around Immediate Implants Placed Using Contour Augmentation: A Prospective Case Series

The purpose of this study was to prospectively evaluate the dimensional bone changes around implants placed immediately with buccal contour augmentation. Patients with hopeless maxillary anterior teeth were treated with extraction, immediate implant placement, and simultaneous buccal contour augmentation. Hard tissue measurements were recorded at the time of implant placement and after 3 months of healing. All implants (N = 18) successfully osseointegrated with a mean buccal bone thickness of 2.94 ± 0.21 mm (mean ± SE) at the implant platform. This was significantly greater compared to previous data on immediate implants placed without contour augmentation (2.32 ± 0.17 mm). Buccal contour augmentation in conjunction with immediate implant placement significantly increased peri-implant buccal bone thickness after 3 months of healing.

Evaluation of Healing at Molar Extraction Sites With and Without Ridge Preservation: A Randomized Controlled Clinical Trial

BACKGROUND

To date, limited evidence is available specifically evaluating ridge preservation (RP) and implant placement in molar sites. The primary aim of this study is to radiographically compare alveolar ridge changes with and without RP with cone-beam computed tomography (CBCT).

METHODS

This parallel, two-arm randomized clinical trial included 40 patients evenly distributed between two treatment groups. After molar extraction, sites were allowed to heal naturally or received RP with freeze-dried bone allograft covered by a non-resorbable dense polytetrafluoroethylene membrane. CBCT scans were taken immediately and 3 months postextraction, and then a dental implant was placed. Width and height measurements were made radiographically.

RESULTS

Significantly greater loss in alveolar ridge height was found in molar sites allowed to heal without RP on the buccal aspect of the socket (RP: -1.12 ± 1.60 mm versus no RP: -2.60 ± 2.06 mm, P = 0.01). No significant difference in ridge width loss was found between groups. Two-thirds ridge width reduction was experienced on the buccal aspect in sites without RP, but width loss was evenly distributed between buccal and lingual aspects when RP was performed. Bone grafting at time of placement was required in 25% of implants in the group without RP versus 10% of implants in the RP group.

CONCLUSIONS

In molar extraction sites without RP, significantly more reduction in ridge height occurred, and the majority of ridge width loss was localized to the buccal aspect. When RP was performed, ridge width loss was not significantly decreased, but the loss was evenly distributed between facial and lingual aspects of the extraction site.

A cone beam computed tomography (CBCT) study of buccal plate thickness of the maxillary and mandibular posterior dentition

BACKGROUND

Buccal plate thickness is of clinical importance in treatment planning for implants. The purpose of this study was to evaluate the buccal plate thickness in posterior dentate areas of both the maxilla and mandible using cone beam computed tomography in order to estimate the approximate distributions of this anatomic variable.

METHODS

Two hundred and sixty-five subjects were included for a total of nine hundred and thirty-four roots assessed by cone beam computed tomography. CBCT scans were taken and evaluated at the ideal buccolingual cross-sections of each root at 1 mm, 3 mm, and 5 mm apical to the alveolar crest to measure buccal plate thickness. Data are reported by geometric means and 95% confidence intervals.

RESULTS

Both arches demonstrated increasing buccal plate thickness from anterior to posterior. Maxillary teeth had a significant decrease in thickness from coronal to apical along the tooth root (P < 0.001), except at second molars. The first premolar and mesial root of the first molar were significantly thinner than all other roots in the maxilla. Conversely, the mandible demonstrated a significant increase in buccal plate thickness from coronal to apical (P < 0.001). The premolars were significantly thinner than all other roots. Age and sex were found to have limited impact on buccal plate thickness in both arches.

CONCLUSIONS

Buccal plate thickness is highly dependent upon the arch position, tooth location, and measurement point, but age and sex have limited impact.

Biologic width around different implant-abutment interface configurations. A radiographic evaluation of the effect of horizontal offset and concave abutment profile in the canine mandible

PURPOSE

The purpose of this experimental study was to analyze radiographically in a dog model how different implant-abutment interface configurations influence alveolar crestal bone changes.

MATERIALS AND METHODS

Six different experimental implant-abutment connections were evaluated in six mixed-breed dogs. The following parameters were tested: absence of microgap, microgap proximal to bone crest, and microgap distant from bone crest. In addition, two different cervical abutment profiles, one straight and one featuring a supracrestal concavity, were evaluated. Implants were based on a cylindrical full-body screw design and made from cold-worked grade IV commercially pure titanium. The diameter (at thread tips) measured 4.1 mm, whereas the inner diameter was 3.5 mm. Standardized periapical digital radiographs were obtained for comparative analysis at baseline and at 3, 4, 5, 6, 7, 8, and 9 months after implant placement. Radiographs were randomized and calibrated for linear measurements. For statistical analysis, mixed-model repeated-measures analysis of variance was used.

RESULTS

All implants integrated successfully and remained stable during the entire period of the study. Radiographically, when comparing groups with straight profiles, crestal bone remodeling in group C (one-piece design) was significantly less than in group A (matching diameters) and B (nonmatching diameters). In fact, implant group C showed the least crestal bone remodeling of all groups. When comparing groups with a concave profile but different microgap configurations, all three designs demonstrated bone loss with no significant differences among the three groups.

CONCLUSION

A nonsubmerged one-piece implant design demonstrated the least amount of bone remodeling of all groups. Implant-abutment connections with a concave profile established crestal bone levels immediately apical to the concavity regardless of the microgap variable.

Formulating a global prognosis and treatment plan for the periodontally compromised patient: a reconstructive vs. an adaptive approach

The clinician faces treatment planning challenges when patients present with generalized severe chronic periodontitis that may result in tooth loss. This article provides a treatment planning discussion along with approaches for treating such patients. It presents the clinical question: What is the best means for approaching treatment planning in a patient with severe periodontitis requiring extraction and replacement of some teeth? Two treatment approaches are discussed—a reconstructive approach versus an adaptive one—both of which have an end goal of achieving periodontal health and occlusal stability, and each has its own advantages and disadvantages. In conclusion, utilizing a global prognostic approach will assist clinicians anticipate the eventual restorative needs of patients and prescribe customized periodontal and restorative therapies that best address those needs.

Buccal bone formation after flapless extraction: a randomized, controlled clinical trial comparing recombinant human bone morphogenetic protein 2/absorbable collagen carrier and collagen sponge alone

BACKGROUND

Flapless extraction of teeth allows for undisturbed preservation of the nearby periosteum and a source of osteoprogenitor cells. Recombinant human bone morphogenetic protein 2 (rhBMP-2) has been used for different bone augmentation purposes with great osteoinductive capacity. The aim of this study is to compare the bone regenerative ability of rhBMP-2 on an absorbable collagen sponge (ACS) carrier to a collagen sponge (CS) alone in extraction sites with ≥50% buccal dehiscence.

METHODS

Thirty-nine patients requiring extraction of a hopeless tooth with ≥50% buccal dehiscence were enrolled. After flapless extraction and randomization, either rhBMP-2/ACS carrier or CS alone was placed in the extraction site. After extraction, a baseline cone beam computed tomography (CBCT) scan was obtained of the site, and a similar scan was obtained 5 months postoperatively. Medical imaging and viewing software were used to compare the baseline and 5-month postoperative images of the study site and assess ridge width measurements, vertical height changes, and buccal plate regeneration.

RESULTS

Radiographically, CBCT analysis showed that with ≥50% of buccal bone destruction, rhBMP-2/ACS was able to regenerate a portion of the lost buccal plate, maintain theoretical ridge dimensions, and allow for implant placement 5 months after extraction. The test group performed significantly (P <0.05) better in regard to clinical buccal plate regeneration (4.75 versus 1.85 mm), clinical ridge width at 5 months (6.0 versus 4.62 mm), and radiographic ridge width at 3 mm from the alveolar crest (6.17 versus 4.48 mm) after molar exclusion. There was also significantly (P <0.05) less remaining buccal dehiscence, both clinically (6.81 versus 10.0 mm) and radiographically (3.42 versus 5.16 mm), at 5 months in the test group. Significantly (P <0.05) more implants were placed in the test group without the need for additional augmentation. The mean loss in vertical ridge height (lingual/palatal) was less in the test sites but was not significantly (P = 0.514) different between the test and control groups (0.39 versus 0.64 mm).

CONCLUSIONS

rhBMP-2/ACS compared to CS alone used in flapless extraction sites with a buccal dehiscence is able to regenerate lost buccal plate, maintain theoretical ridge dimensions, and allow for implant placement 5 months later.

Induction of apoptosis in oral epithelial cells by Candida albicans

During infection, interactions between Candida albicans and oral epithelial cells result in oral epithelial cell death. This is clinically manifested by the development of oral mucosal ulcerations generally associated with discomfort. In vitro studies have shown that C. albicans induces early apoptotic alterations in oral epithelial cells; however, these studies have also shown that treatment of infected cells with caspase inhibitors does not prevent their death. The reasons for these contradictory results are unknown and it is still not clear if C. albicans stimulates oral epithelial signaling pathways that promote apoptotic cell death. Activation of specific death pathways in response to microbial organisms plays an essential role in modulating the pathogenesis of a variety of infectious diseases. The aim of this study was to (i) characterize C. albicans-induced apoptotic morphological alterations in oral epithelial cells, and (ii) investigate the activation of apoptotic signaling pathways and expression of apoptotic genes during infection. Candida albicans induced early apoptotic changes in over 50% of oral epithelial cells. However, only 15% of those showed mid-late apoptotic alterations. At the molecular level, C. albicans caused a loss of the mitochondrial transmembrane potential and translocation of mitochondrial cytochrome c. Caspase-3/9 activities increased only during the first hours of infection. Moreover, poly[ADP ribose] polymerase 1 was cleaved into apoptotic and necrotic-like fragments. Finally, five anti-apoptotic genes were significantly upregulated and two pro-apoptotic genes were downregulated during infection. Altogether, these findings indicate that epithelial apoptotic pathways are activated in response to C. albicans, but fail to progress and promote apoptotic cell death.

Matrix metalloproteinases, tissue inhibitors of matrix metalloproteinases, and inflammation in cyclosporine A-induced gingival enlargement: a pilot in vitro study using a three-dimensional model of the human oral mucosa

BACKGROUND

It has been suggested that cyclosporine A (CsA) induces gingival enlargement by promoting an increase in the gingival extracellular matrix (ECM). Nonetheless, the variable occurrence of CsA-induced gingival enlargement in patients receiving this medication indicates a multifactorial pathogenesis. Clinical observations suggest that local inflammation is associated with the development and severity of CsA-induced gingival enlargement. Therefore, the purpose of this study is to investigate the effects of CsA and inflammation on the production of ECM homeostatic mediators.

METHODS

The effects of CsA and inflammation (as assessed using interleukin [IL]-1β) on the secretion of mediators involved in ECM homeostasis were determined using fibroblast monolayers and three-dimensional (3D) models of the human oral mucosa. Fibroblast monolayers and 3D cultures were treated with CsA alone or in combination with IL-1β for up to 72 hours, and the secretion of matrix metalloproteinases (MMPs) 1, 2, 3, 8, 9, 10, and 13 and tissue inhibitors of MMPs (TIMPs) 1, 2, and 4 into the culture medium was assessed using enzyme-linked immunoassay-based antibody arrays.

RESULTS

Fibroblast monolayers responded to CsA with no changes in the secretion of ECM mediators. Conversely, 3D cultures responded to CsA treatment with a reduction in MMP-10 secretion. IL-1β alone triggered higher secretory levels of MMPs in both fibroblast monolayers (MMP-3 and MMP-10) and 3D cultures (MMP-9 and MMP-10). Importantly, fibroblast monolayers and 3D cultures treated with a combination of IL-1β and CsA showed a decrease in the MMP-1/TIMP-1 ratio.

CONCLUSIONS

These data support the hypothesis that inflammation may alter the pathogenesis of CsA-induced gingival enlargement by promoting a synergistic decrease in the MMP-1/TIMP-1 ratio.

Diabetes Effects on Dental Implant Survival

The goal of this review is to critically appraise the clinical evidence guiding our application of dental implant therapy relative to glycemic control for patients with diabetes. Our initial searches of the literature identified 129 publications relevant to both dental implants and diabetes. These were reduced to 17 clinical studies for inclusion. Reported implant failure rates in these 17 reports ranged from 0 to 14.3% for patients with diabetes. Unfortunately, the majority of these reports lacked sufficient information relative to glycemic control to allow the application of the findings toward clinical care. However, clinical evidence is emerging from several investigations that diabetes and glycemic control are important considerations that may require modifications to therapeutic protocols, but may not be contraindications to implant therapy in diabetes patients. Also, a potentially important role for implant therapy to support oral function in diabetes dietary management remains to be determined.

A critical review of diabetes, glycemic control, and dental implant therapy

OBJECTIVES

To systematically examine the evidence guiding the use of implant therapy relative to glycemic control for patients with diabetes and to consider the potential for both implant therapy to support diabetes management and hyperglycemia to compromise implant integration.

MATERIAL AND METHODS

A systematic approach was used to identify and review clinical investigations directly assessing implant survival or failure for patients with diabetes. A MEDLINE (PubMED) database search identified potential articles for inclusion using the search strategy: (dental implants OR oral implants) AND (diabetes OR diabetic). Inclusion in this review required longitudinal assessments including at least 10 patients, with included articles assessed relative to documentation of glycemic status for patients.

RESULTS

Although the initial search identified 129 publications, this was reduced to 16, for inclusion. Reported implant failure rates for diabetic patients ranged from 0% to 14.3%. The identification and reporting of glycemic control was insufficient or lacking in 13 of the 16 studies with 11 of these enrolling only patients deemed as having acceptable glycemic control, limiting interpretation of findings relative to glycemic control. Three of the 16 studies having interpretable information on glycemic control failed to demonstrate a significant relationship between glycemic control and implant failure, with failure rates ranging from 0% to 2.9%.

CONCLUSIONS

Clinical evidence is lacking for the association of glycemic control with implant failure while support is emerging for implant therapy in diabetes patients with appropriate accommodations for delays in implant integration based on glycemic control. The role for implants to improve oral function in diabetes management and the effects of hyperglycemia on implant integration remain to be determined.

Analysis of the socket bone wall dimensions in the upper maxilla in relation to immediate implant placement

BACKGROUND

Animal and human researches have shown that immediate implant placement into extraction sockets failed to prevent socket dimensional changes following tooth extraction. It has been suggested that a minimal width of 1-2 mm of buccal bone is necessary to maintain a stable vertical dimension of the alveolar crest.

AIM

To determine the dimensions of the bony wall at extraction sites in the esthetic zone (anterior teeth and premolars in the maxilla) and relate it to immediate implant placement.

METHODS

As part of an ongoing prospective randomized-controlled multicenter clinical study on immediate implant placement, the width of the buccal and palatal bony walls was recorded at 93 extraction sites.

RESULTS

The mean width of the buccal and palatal bony walls was 1 and 1.2 mm, respectively (P<0.05). For the anterior sites (canine to canine), the mean width of the buccal bony wall was 0.8 mm. For the posterior (premolar) sites, it was 1.1 mm (P<0.05). In the anterior sites, 87% of the buccal bony walls had a width < or = 1 mm and 3% of the walls were 2 mm wide. In the posterior sites, the corresponding values were 59% and 9%, respectively.

CONCLUSIONS

If the criterion of a minimal buccal bone width of 2 mm to maintain a stable buccal bony wall is valid, only a limited number of sites in the anterior maxilla display such a clinical situation. The data suggested that in the majority of extraction sites in the anterior maxilla, thin (< or = 1 mm) buccal walls were present. This, in turn, means that in most clinical situations encountered, augmentation procedures are needed to achieve adequate bony contours around the implant.

Implant failure predictors in the posterior maxilla: a retrospective study of 273 consecutive implants

BACKGROUND

The goal of this study was to retrospectively analyze a cohort of 136 patients who underwent dental implant placement in the posterior maxilla at the University of Connecticut Health Center to assess and identify predictors for implant failure in the posterior maxilla.

METHODS

Data were retrieved from patient charts to identify subjects older than 21 years of age who received dental implant(s) in the posterior maxilla. Patients without a postoperative baseline radiograph were excluded. A recall radiograph was taken 3 to 6 months after implant placement. If there was no recall radiograph, the subject was contacted for a recall visit that included a clinical evaluation and radiographs to determine the implant status. Based on a univariate screening, variables considered potential implant failure predictors included gender, diabetes, smoking, implant length, implant diameter, membrane use, sinus-elevation technique, and surgical complications. These parameters were further assessed, and a multivariable logistic regression was performed with implant failure as a dependant variable. All tests of significance were evaluated at the 0.05 error level.

RESULTS

Two hundred seventy-three implants were placed in the posterior maxilla. Fourteen implants failed (early and late failures combined), resulting in a 94.9% overall survival rate. The survival rates for the sinus-elevation group and native bone group were 92.2% and 96.7%, respectively (P = 0.090). Based on the multivariable analysis, sinus floor-elevation procedures were not associated with increased risk for implant failure (P = 0.702). In contrast, smoking and surgical complications had a statistically significant effect on implant failure; the odds ratios for implant failure were 6.4 (P = 0.025) and 8.2 (P = 0.004), respectively.

CONCLUSION

Sinus-elevation procedures with simultaneous or staged implant placement do not increase the risk for implant failure, whereas smoking and surgical complications markedly increase the risk for implant failure.

Association of the composite IL-1 genotype with peri-implantitis: a systematic review

OBJECTIVE

Cytokine gene polymorphisms may modulate the host response to the bacterial challenge and influence susceptibility to peri-implantitis.

OBJECTIVE

To systematically review the evidence of an association between the interleukin-1 (IL-1) composite genotype, i.e. presence of the allele 2 in the gene clusters IL-1A (-889) and in IL-1B (+3953), and peri-implantitis.

MATERIAL AND METHODS

An electronic search in the National Library of Medicine-computerized bibliographic database MEDLINE and a manual search were performed. The search was conducted for longitudinal clinical trials comparing progression of peri-implantitis in IL-1 genotype positive (carrying allele 2) with IL-1 genotype negative (not carrying allele 2) subjects. Selection of publications, extraction of data and validity assessment were made independently by two reviewers.

RESULTS

The search provided 44 titles of which two longitudinal publications were included.

CONCLUSION

Based on the findings from this study, there is not enough evidence to support or refute an association between the IL-1 genotype status and peri-implantitis. Systematic genetic testing for the assessment of the risk of peri-implantitis cannot be recommended as a standard of care at this time.

History of treated periodontitis and smoking as risks for implant therapy

PURPOSE

The aim of this review was to evaluate a history of treated periodontitis and smoking, both alone and combined, as risk factors for adverse dental implant outcomes.

MATERIALS AND METHODS

A literature search of MEDLINE (Ovid) and EMBASE from January 1, 1966, to June 30, 2008, was performed, and the outcome variables implant survival, implant success, occurrence of peri-implantitis and marginal bone loss were evaluated.

RESULTS

Considerable heterogeneity in study design was found, and few studies accounted for confounding variables. For patients with a history of treated periodontitis, the majority of studies reported implant survival rates > 90%. Three cohort studies showed a higher risk of peri-implantitis in patients with a history of treated periodontitis compared with those without a history of periodontitis (reported odds ratios from 3.1 to 4.7). In three of four systematic reviews, smoking was found to be a significant risk for adverse implant outcome. While the majority of studies reported implant survival rates ranging from 80% to 96% in smokers, most studies found statistically significantly lower survival rates than for nonsmokers.

CONCLUSIONS

There is an increased risk of peri-implantitis in smokers compared with nonsmokers (reported odds ratios from 3.6 to 4.6). The combination of a history of treated periodontitis and smoking increases the risk of implant failure and peri-implant bone loss.

Restoration margins in young adolescents: a clinical and radiographic study of Swiss Army recruits

PURPOSE

The aim of the present study was to report the radiographical prevalence of overhanging fillings in a group of Swiss Army recruits in 2006 and to relate the dimensions of the overhangs to clinical parameters.

MATERIALS AND METHODS

A total of 626 Swiss Army recruits were examined for their periodontal conditions, prevalence of caries, and stomatological and functional aspects of the masticatory system and halitosis. In particular, the present report deals with the presence or the absence of fillings, the presence or the absence of overhangs and their relation to clinical and radiographic parameters.

RESULTS

A total of 16,198 interdental sites were evaluated on bitewing radiographs. Of these sites, 15,516 (95.8%) were sound and 682 (4.2%) were filled. Amalgam restorations were found in 94.1% and resin composite fillings in 5.9% of the sites. Of these 682 sites, 96 (14.1%) yielded overhanging margins of various sizes. This low prevalence of fillings represents not only a substantial reduction when compared with a similar Swiss Army study (Lang et al, 1988), but also an improvement in the quality of dental care delivery to young Swiss males. Plaque Index and Gingival Index increased statistically significantly with the presence of fillings, when compared with healthy non-filled sites. Clinical parameters that were significantly associated with the presence of overhangs included clinical attachment loss. Moreover, between 1985 and 2006 the prevalence of fillings was significantly reduced from 20.0% to 4.2% of all surfaces. Furthermore, the marginal fit of the fillings improved from 33.0% with overhangs to 14.1%.

CONCLUSIONS

A significant improvement was observed in the periodontal and dental conditions of young Swiss males that was shown to have taken place within the previous two decades. From 1985 to 2006, the prevalence of fillings was reduced fourfold and that of overhanging margins twofold, documenting an improvement in the quality of restorative dentistry.

The association of the composite IL-1 genotype with periodontitis progression and/or treatment outcomes: a systematic review

BACKGROUND

Genetically transmitted traits such as cytokine gene polymorphisms may accentuate the host inflammatory response to the bacterial challenge and influence susceptibility to periodontitis.

OBJECTIVE

To systematically review the evidence of an association between the interleukin-1 (IL-1) composite genotype, i.e. presence of the allele 2 in the gene clusters IL-1A-889 and in IL-1B +3953, and periodontitis progression and/or treatment outcomes.

MATERIAL AND METHODS

Based on the focused question, a search was conducted for longitudinal clinical trials comparing progression of periodontitis and/or treatment outcomes in IL-1 genotype-positive (carrying allele 2) and IL-1 genotype-negative (not carrying allele 2) subjects. A search in the National Library of Medicine computerized bibliographic database MEDLINE and a manual search were performed. Selection of publications, extraction of data and validity assessment were made independently by two reviewers.

RESULTS

The search provided 122 titles of which 11 longitudinal publications were included. The heterogeneity of the data prevented the performance of a meta-analysis. While findings from some publications rejected a possible role of IL-1 composite genotype on progression of periodontitis after various therapies, other reported a prognostic value for disease progression of the positive IL-1 genotype status. When assessed on a multivariate risk assessment model, several publications concluded that the assessment of the IL-1 composite genotype in conjunction with other covariates (e.g. smoking and presence of specific bacteria) may provide additional information on disease progression. The small sample size of the available publications, however, requires caution in the interpretation of the results.

CONCLUSION

Based on these findings, (i) there is insufficient evidence to establish if a positive IL-1 genotype status contributes to progression of periodontitis and/or treatment outcomes. Therefore, (ii) results obtained with commercially available tests should be interpreted with caution.