Alveolar ridge preservation: Complications and cost-effectiveness.

Alveolar ridge preservation is routinely indicated in clinical practice with the purpose of attenuating postextraction ridge atrophy. Over the past two decades numerous clinical studies and reviews on this topic have populated the literature. In recent years the focus has primarily been on analyzing efficacy outcomes pertaining to postextraction dimensional changes, whereas other relevant facets of alveolar ridge preservation therapy have remained unexplored. With this premise, we carried out a comprehensive evidence-based assessment of the complications associated with different modalities of alveolar ridge preservation and modeled the cost-effectiveness of different therapeutic modalities as a function of changes in ridge width and height. We conclude that, among allogeneic and xenogeneic bone graft materials, increased expenditure does not translate into increased effectiveness of alveolar ridge preservation therapy. On the other hand, a significant association between expenditure on a barrier membrane and reduced horizontal and vertical ridge resorption was observed, though only to a certain degree, beyond which the return on investment was significantly diminished.

Assessment of soft and hard tissue characteristics of ridge preservation at molar extraction sites with severe periodontitis: a randomized controlled trial.

BACKGROUND: Changes in alveolar bone dimension after tooth extraction may affect placement of the subsequent implant, resulting in ridge deficiency that can adversely impact long-term implant stability or aesthetics. Alveolar ridge preservation (ARP) was effective in reducing the amount of ridge resorption following tooth extraction. There is sparse evidence regarding the benefit of ARP at periodontally compromised molar extraction sockets. This study will be a randomized trial to assess the soft tissue contour, radiographical, and histological changes of ARP at molar extraction sites in order to compare severe periodontitis cases with natural healing results and determine the most beneficial and least traumatic clinical treatment for such patients. METHODS: This research is designed as a two-group parallel randomized controlled trial. The total number of tooth extraction sites will be 70 after calculation with power analysis. Teeth will be randomly assigned to two groups with the test group conducting ridge preservation and the control group healing naturally. Periodontal examination, cone beam-computed tomography (CBCT) data, and stereolithographic (STL) files obtained by intraoral scanning will be collected through the follow-up period, and bone biopsy samples would be obtained during implant surgery. The primary outcomes are the vertical and horizontal change of alveolar ridge measured on CBCT images, soft tissue contour changes evaluated by superimposing the digital impressions, alterations of mucosa thickness (as measured by superimposing the CBCT data and STL files), histological features of implant sites and periodontal parameter changes. The secondary outcomes are patient-reported post-operative reaction and conditions of simultaneous bone graft or sinus lifting procedures during implantation. DISCUSSION: This study will provide information about hard and soft tissue dimension changes and histomorphology evaluation following ARP and natural healing in periodontally compromised molar sites, which may contribute to complement the missing information of ARP at periodontally compromised molar extraction sockets. TRIAL REGISTRATION: Chinese Clinical Trial Register (ChiCTR) ChiCTR2200056335. Registered on February 4, 2022, Version 1.0.

Comparing the histological assessment following ridge preservation using a composite bovine-derived xenograft versus an alloplast hydroxyapatite-sugar cross-linked collagen matrix.

BACKGROUND: This randomized controlled trial was designed to evaluate the histological wound healing and alveolar ridge dimensional changes following ridge preservation using two different xenograft/collagen matrices. METHODS: Fifty-four patients each with non-molar teeth that required extraction and replacement with dental implants were enrolled. Teeth extractions were completed with minimal flap reflection and were randomized to receive ridge preservation with either 90% bovine-derived xenograft granules in a 10% porcine collagen matrix (Group A) or a sponge-like matrix of 80% microparticulate hydroxyapatite alloplast graft with 20% sugar cross-linked porcine type 1 collagen (Group B). After 16 weeks of healing and at the time of implant placement, a bone core biopsy was harvested followed by dental implant placement. The primary histological outcome evaluated were percentage of vital bone formation and connective tissue/other (fibrous tissue and marrow space). Secondary outcomes included the change in alveolar ridge width and the buccal and lingual ridge height. Statistical analysis was completed with two-sample t-test and Fisher exact test. RESULTS: Forty-four patients completed the study, 23 in group A and 21 in group B. Group B presented with statistically significantly (p = 0.02) more percentage of vital bone (39.3 ± 17.8) than group A (26.8 ± 15.8). No statistically significant difference was observed for changes in alveolar ridge dimensions. CONCLUSIONS: Group B, when used for ridge preservation, yields statistically significantly more vital bone over a 4-month healing period. Ridge dimension changes were similar between the two groups and were adequate for implant placement.

Assessment of a Novel Alveolar Ridge Preservation Concept in Dehiscence Sockets: A Pilot Study.

In this prospective pilot study on ridge preservation (RP), a collagen sponge was placed to fill the bottom half of the socket, followed by a sequence of bone graft, collagen membrane, and a sponge placed on top. Twelve patients with 13 hopeless posterior teeth were included. Changes in bone dimension (including variations of horizontal ridge width [HRW] and bone height [BH]) between the time immediately postextraction (T0) and 6 months later (T6M) were evaluated through CBCT. The soft tissue was assessed using a wound healing index (WHI) at 2 weeks (T2W), 2 months (T2M), and 6 months (T6M) postsurgery. Measured at three parallel levels (1, 3, and 5 mm apical to the crest of the palatal plate), the mean HRW changes (T0 to T6M) ranged from 0.47 to 1.05 mm. Statistically significant negative correlations were observed between WHI (T6M) and midcrestal BH change. This proposed RP technique showed favorable outcomes regarding HRW and BH, even in periodontally compromised dehiscence sockets.

Simultaneous Assessment of Soft and Hard Tissue Behaviors After Alveolar Ridge Preservation Using Bone Substitutes.

This study aimed to simultaneously assess hard and soft tissues alterations and their proportions after alveolar ridge preservation (ARP). Participants (n = 65) who were previously enrolled in a clinical trial investigating ARP healing were selected. The CBCT DICOM (Digital Imaging and Communications in Medicine) and the cast STL (stereolithographic) files of each subject were imported, segmented, and superimposed. A cross-section view of the superimposed image presented the outlines from each DICOM and STL file. The center of preserved ridge was selected in the superimposed image and used to draw the reference lines to realize the measurements. Horizontal linear measurements determined ridge width (RW) and its respective hard/soft tissue proportion (H:S) at 1, 3, 5, and 7 mm below the buccal bone crest immediately after ARP and at the 4-month follow-up. At 1 mm, the baseline RW was 11.6 mm and reduced to 10 mm after 4 months. The baseline H:S was 65%:35% and was 43%:57% at the 4-month follow-up. Considering only the buccal half of the ridge, baseline H:S was 77%:23%, while after 4 months it shifted to 58%:42%. A similar pattern was observed at 3, 5, and 7 mm but with decreased resorption degree. The present study showed that hard tissue is mostly responsible for RW loss after healing, especially in the first 3 mm below the buccal bone crest. Soft tissue partially compensated for the hard tissue shrinkage, gaining thickness in the analyzed areas.

Three-Dimensional Radiological Assessment of Alveolar Bone Volume Preservation Using Bovine Bone Xenograft.

INTRODUCTION: Alveolar bone is critical in supporting natural teeth, dental implants as well as a removable and fixed prosthesis. Alveolar bone volume diminishes when its associated natural tooth is lost. OBJECTIVE: The aim of this study is to evaluate the effectiveness of bovine bone granules on alveolar bone socket augmentation for ridge preservation following atraumatic tooth extraction. MATERIALS AND METHODS: Twenty medically fit patients (12 males and 8 females aged between 18 and 40 years) who needed noncomplicated tooth extraction of 1 mandibular premolar tooth were divided randomly and equally into 2 groups. In control group I, the empty extraction socket was left untreated and allowed to heal in a conventional way. In group II, the empty extraction socket wound was filled with lyophilized bovine bone xenograft granules 0.25 to 1 mm of size, 1 mL/vial. A resorbable pericardium membrane was placed to cover the defect. Clinical and 3-dimensional radiological assessments were performed at day 0, 3 months, and 9 months postoperative. RESULTS: There were no clinical differences in general wound healing between the groups. Comparisons within the groups showed a significant difference of bone resorption of 1.49 mm (95% confidence interval, 0.63-2.35) at 3 months, and further resorption of 1.84 mm (P ≤ 0.05) at 9 months in the control group. No significant changes of bone resorption were observed in group II during the same time interval. Comparison between groups showed a significant difference of bone resorption at 3 and 9 months (2.40 and 2.88 mm, respectively). CONCLUSION: The use of lyophilized demineralized bovine bone granules in socket preservation to fill in the extraction socket seems essential in preserving the alveolar bone dimension as it showed excellent soft and hard tissue healing. This study concludes that the alveolar bone socket exhibited a dynamic process of resorption from the first day of tooth extraction. Evidence shows the possibility of using bovine bone granules routinely in socket volume preservation techniques following tooth extraction.

A Prospective Clinical and Radiographic Assessment of Platform-Switched Laser-Microchannel Implants Placed in Limited Interimplant Spaces.

This multicenter clinical trial of platform-switched laser-microchannel implants supports findings from a previous preclinical trial. Previous information indicated that an interimplant distance narrower than 3 mm would result in decrease in the crestal bone level, but the results of this investigation suggest that a more optimistic clinical result can be anticipated for implants and abutments with a laser-microchannel surface.

Assessment of vascular endothelial growth factor and matrix metalloproteinase-9 in the periodontium of rats treated with atorvastatin.

BACKGROUND: The aim of this study is to examine, for the first time, the role of systemic and local atorvastatin application on periodontium using histomorphometric and immunohistochemical analysis during and after experimental periodontitis induction with or without the presence of microbial dental biofilm. METHODS: One hundred ten male Wistar rats were used. Silk ligatures were placed around the cervical area of the mandibular first molars; rats in the healthy control group received no ligatures (n = 10). In experimental periodontitis groups (n = 90), systemic and local atorvastatin and saline were administered in three different periods; the control periodontitis group (n = 10) received no treatment. Histomorphometric analysis, which included alveolar bone area, alveolar bone level, and attachment loss, and immunohistochemical analysis, which included immunoreactivity of vascular endothelial growth factor (VEGF) and matrix metalloproteinase (MMP)-9, were performed after the rats were sacrificed at the end of the experimental procedure. RESULTS: There was a greater increase in alveolar bone area and VEGF immunoreactivity, as well as a greater decrease in alveolar bone and attachment loss and MMP-9 immunoreactivity, with systemic and local atorvastatin application during and after induction of experimental periodontitis. Local atorvastatin application showed better results on periodontium with regard to alveolar bone findings. CONCLUSIONS: Systemic and local atorvastatin application showed beneficial effects on periodontium during and after induction of experimental periodontitis. Within the limits of this study, it can be concluded that atorvastatin, which is used for hypercholesterolemia treatment, can also be used as a protective and therapeutic agent for periodontal disease.

Quality assessment of systematic reviews on alveolar ridge preservation.

BACKGROUND: The authors conducted a study to assess the quality of systematic reviews (SRs) published on the topic of alveolar ridge preservation (ARP). TYPES OF STUDIES REVIEWED: The authors conducted a search for SRs on ARP on the basis of a set of eligibility criteria (only SRs involving ARP, with or without meta-analyses, written in English). The authors assessed the quality of the SRs independently of one another by using two established checklists. RESULTS: The authors selected eight SRs. The results of all of the SRs indicated that ARP was effective in preserving the ridge volume as compared with extraction alone, but it did not fully prevent bone-resorptive events. None of the SRs, however, received the highest possible score in either of the checklists. One SR that had a score of 5 (of a possible 11) using one checklist and 5 (of a possible 14) using the other checklist had the lowest overall score. The results of this assessment revealed that a significant proportion of the investigators in the SRs did not include non-English language articles, perform hand searching of published literature or evaluate the gray literature. Assessment of publication bias and reporting of conflicts of interest also was lacking in some studies. Practical Implications. Although ARP appears to be an effective approach to preventing resorption after tooth extraction, significant structural and methodological variability exists among SRs on this topic. Future SRs on ARP should consider the use of quality assessment checklists to minimize methodological shortcomings for better dissemination of scientific evidence.

New attempts to modify periodontal risk assessment for generalized aggressive periodontitis: a retrospective study.

BACKGROUND: Periodontal risk assessment (PRA) model was designed for risk evaluation of treated patients with periodontal disease. However, its use on generalized aggressive periodontitis (GAgP) had been scarcely reported. This study aims to investigate the association of original PRA/modified PRA (MPRA) and compliance of periodontal maintenance with long-term treatment outcomes of Chinese patients with GAgP. METHODS: Eighty-eight patients from a GAgP cohort, who completed active periodontal treatment (APT) and accepted reevaluation 3 to 11 years (mean of 5.5 years) afterward, were enrolled. PRA was modified (three strategies involving replacement of bleeding on probing with bleeding index >2, counting sites with probing depth ≥6 mm and changing method of bone loss [BL] calculation) to classify patients into different risk groups based on data at the first recall after APT. PRA and three MPRA models were investigated regarding long-term association with tooth loss (TL) and alteration of bone level (∆BL). RESULTS: Based on original PRA, 87 patients (98.8%) had a high-risk profile. According to three MPRA models, annual TL per patient values were greater in high-risk groups than in low-to-moderate risk groups (MPRA-1, 0.20 ± 0.33 versus 0.04 ± 0.14; MPRA-2, 0.18 ± 0.32 versus 0.05 ± 0.14; MPRA-3, 0.17 ± 0.32 versus 0.05 ± 0.15; P <0.05). By MPRA-1, irregular compliers with low-to-moderate risk profile had greater ∆BL (0.027 ± 0.031, indicating bone increment) than those with high risk (-0.012 ± 0.064, tendency for BL). For regular compliers, no significant differences of annual TL or ∆BL were found between risk groups. CONCLUSIONS: MPRA models could be used for evaluating the long-term outcomes of Chinese patients with severe GAgP, especially irregular compliers. High-risk patients of MPRAs exhibited more TL and less bone fill than low-to-moderate risk ones.

Periodontal risk assessment model in a sample of regular and irregular compliers under maintenance therapy: a 3-year prospective study.

BACKGROUND: The purpose of this study is to investigate the association of the periodontal risk assessment (PRA) model with the recurrence of periodontitis and tooth loss during periodontal maintenance therapy (PMT). METHODS: In a prospective PMT program, 75 regular complier (RC) and 89 erratic complier (EC) patients were selected. A periodontal examination and PRA were performed after active periodontal therapy and after 3 years of PMT. Risk profiles (low, moderate, or high) of participants were evaluated, and the recurrence of periodontitis and tooth loss were analyzed using univariate and multivariate analyses. RESULTS: RCs showed less recurrence of periodontitis and tooth loss than ECs (P <0.05). Rates of periodontitis recurrence in RCs and ECs were 2.7% and 3.4%, respectively, for the moderate-risk profile and 6.7% and 11.2%, respectively, for the high-risk profile. During PMT, 49 teeth (0.65 ± 1.4 teeth per participant) were lost in the RC group, and 70 teeth (0.78 ± 2.1 teeth per participant) were lost in the EC group. High-risk profile participants showed more recurrence of periodontitis and lost significantly more teeth than did participants with moderate- or low-risk profiles in RC and EC groups (P <0.05). CONCLUSION: The risk profile influenced the recurrence of periodontitis and tooth loss. RCs had less recurrence of periodontitis and less tooth loss. The PRA model can be useful in particularizing the risk of patients and adjusting recall intervals.

Endodontic prognosis assessment.

There are several variables which must be considered before initiating endodontic treatment, including assessing the feasibility of endodontic treatment, addressing past, present and future periodontal concerns, determining the restorability of the tooth, and detecting root fractures. If these parameters are not carefully evaluated, then short- or long-term endodontic success may be questionable. Endodontic prognosis assessment is often subjective, based on objective finding, but ultimately determined by the experience of the operator. Although dentists must rely upon evidence-based research to determine the best modality of treatment, good clinical judgment and experience may override the most objective findings. This article discusses the objective and subjective criteria which must be evaluated for determining the potential prognosis of endodontic treatment.

Risk management in clinical practice. Part 6a. Identifying and avoiding medico-legal risks in complete denture prosthetics.

The provision of complete dentures is often perceived as a clinical 'black art' as it relies on a blend of clinical skill, scientific evidence and no little artistic interpretation. Coupled to this is a heavy reliance on patient ability to control their dentures in a muscular environment while, hopefully, coping with the various oral functions in addition to appearance. This article deals with the potential problem areas in the provision of complete dentures, reinforcing the importance of practitioners obtaining appropriate informed consent and of maintaining clinical knowledge and skills.

[Usefulness of hydroxyapatite implants for the management of alveolar bone lesions at tooth hemisection sites]. / Badanie skutecznosci wszczepów hydroksyapatytowych w leczeniu zniszczen wyrostka zebodolowego w obrebie zebów leczonych metoda hemisekcji.

INTRODUCTION: Hemisection is a surgical method for treating lesions of two- and multi-rooted teeth. This procedure includes amputation of one or two lesioned roots together with the attached dental crown, leaving an endodontically treated root and the remaining dental crown prepared for future prosthetic restoration. The results of this study demonstrate that HA Biocer implants create optimal conditions for new bone growth. MATERIAL AND METHODS: The study was done in 51 patients after hemisection treated with HA Biocer in the form of granules implanted into the alveolus. The control group consisted of 45 patients without an alloplastic implant. The following indices were assessed: radiological index of alveolar bone atrophy in the maxilla and mandible according to Engelberger, Marthaler and Rateischak [EMR]; gingival pocket depth with WHO 621 probe; tooth mobility index according to Entin; root denudation index according to Cieszyfiski; bacterial plaque index (P1.1.) according to Silness and Löe. Measurements were done before hemisection and were repeated after 1.5, 6, 12, 24, 36, 48, and 60 months thereafter. It was found that hydroxyapatite implants improved the condition of the hemisected tooth and arrested the destruction process in the alveolar bone. RESULTS: (1) In the study group (HA Biocer), no bone atrophy was noted in the root region after hemisection, whereas bone loss in the control group reached 11%. (2) The depth of gingival pockets in the study group was half of the depth in the control group. (3) Significant tooth stabilization was achieved in the study group, mainly during the first two years after implantation. Improved tooth stability was noted three times less often in the control group during the same period. (4) Root denudation diminished in patients treated with HA Biocer and increased or remained unchanged in controls. (5) A steady decrease in mean P1.1. index values was observed in both groups over the five-year follow-up period. However, the mean P1.1. value in the study group was one-third of the value in the control group.

Analyzing excessive no changes in clinical trials with clustered data.

This article considers clinical trials in which the efficacy measure is taken from several sites within each patient, such as the alveolar bone height of the tooth sites, or bone mineral densities of the lumbar spine sites. Since usually only a small portion of these sites will exhibit changes, the conventional method using per patient average gives a diluted result due to excessive no changes in the data. Different methods have been proposed for this type of data in the case where the observations are mutually independent. This includes the popular "two-part model" (Lachenbruch, 2001, Statistics in Medicine 20, 1215-1234; 2002, Statistical Methods in Medical Research 11, 297-302), which is related to the "composite approach" for discrete and continuous data in Shih and Quan (1997, Statistics in Medicine16, 1225-1239; 2001, Statistica Sinica 11, 53-62). In this article, we model the data with excessive zeros (no changes) in clustered data using a mixture of distributions, and taking into account possible measurement errors. This mixture model includes the two-part model as a special case when one component of the mixture degenerates.

Clinical, radiographic and biochemical assessment of IL-1/TNF-alpha antagonist inhibition of bone loss in experimental periodontitis.

OBJECTIVES: To assess clinical, radiographic, and biochemical markers as diagnostic indicators of disease activity by comparing ligature-induced bone loss in the presence or absence of IL-1/TNF-alpha antagonist inhibition of bone loss in a primate model. MATERIAL AND METHODS: 6 animals with a naturally-occurring gingivitis were evaluated over a 6-week time period following the placement of silk ligatures and initiation of a soft diet. Three animals received intrapapillary injections of soluble receptors (blockers), capable of blocking the biologic activity for both IL-1 and TNF-alpha, and 3 animals received vehicle (control) injections. Injections were given 3X per week over the course of the study. Clinical assessments included a gingival index and quantification of gingival crevicular fluid (GCF) levels. Collected GCF samples were then used in the biochemical assessment of pyridinoline (PYD) and bone alkaline phosphatase (BAP). Radiographic assessment was made using computer-assisted subtraction radiography to measure both bone density (CADIA) values and linear changes in crestal bone height. RESULTS: Significant (p<0.01) changes using both radiographic measures occurred between 2 and 4 weeks following initiation of disease in this model. The use of the blockers significantly (p<0.01) reduced the levels of radiographic bone loss by approximately 50% over that found in the control sites. Both biochemical markers showed the greatest increase during the first two weeks of the study with PYD levels increased 35-fold over baseline levels after 1 week. This difference in response was significantly (p<0.05) greater than the levels found in the non-ligated teeth or in the ligated teeth receiving blockers injections. BAP levels showed significant increases in ligated teeth compared to non-ligated teeth, but failed to show any significant differences between animals treated with vehicle and those treated with IL-1/TNF antagonists. In contrast to these radiographic and biochemical effects, there were no significant differences detected between animals treated with antagonists and the control group for any of the clinical measures. CONCLUSIONS: The results of this study demonstrate that both subtraction radiography and PYD crevicular fluid levels can detect relative differences in periodontal disease progression, while BAP crevicular fluid levels cannot.

Extraction sites--foundations for restorative excellence.

Preservation of the socket site architecture promotes better esthetics, easier prosthetic treatment, and restoration of the alveolar bone for implant or bridge replacement options. The purported simplicity of the simple extraction can be misleading if the bone housing or soft tissues have been ravaged by disease. This article provides guidelines for case selection, patient consultations, selection of appropriate materials, and a step-by-step methodology for completing successful extraction site therapy.

Osseoretention? Comparative assessment of particulate hydroxyapatite inserted beneath immediate dentures.

This paper presents the results of a study to observe the effect on bone resorption and residual alveolar ridge form, of placement of dense non-resorbable hydroxyapatite granules into fresh canine sockets, at the time of immediate denture provision. Thirty five subjects were randomly divided into two groups cross matched for age and sex. All subjects required bilateral extraction of at least a lower canine and an adjacent tooth. Results demonstrate that six months post-extraction the control group had lost four times more bone than the implant group. These results were highly significant (P=0.000, LHS and P=0.001, RHS).

Utilization of dental services as a risk factor for periodontitis.

The relation between utilization of dental services from community dentists and the extent and severity of alveolar bone loss is reported for a panel of men followed for over 6 years. Oral health data were collected by the Department of Veterans Affairs, Dental Longitudinal Study, which began in 1969 and still continues. Participants have received regular oral examinations approximately every 3 years. A variety of oral health conditions were assessed, including plaque, calculus, gingival inflammation, probing depth, tooth mobility, clinical attachment level, and alveolar bone loss. Utilization data were abstracted from the dental records of dental offices that participants attended from 1979 through 1988. Multivariate modeling as well as comparisons of high utilizers and non-utilizers indicate that utilization of routine diagnostic and preventive services was not predictive of the extent and severity of periodontitis.