Complication and failure rates of fixed dental prostheses in patients treated for periodontal disease

Effect of laser etching on surface characteristics of and porcelain bond to soft milled and direct metal laser sintered cobalt chromium alloys

STATEMENT OF PROBLEM

The surface topography of metal substrate can affect its bond to porcelain. A neodynium-doped yttrium aluminum garnet (Nd:YAG) laser has been introduced to modify the metal surface topography and improve porcelain bond strength. However, studies on the effect of laser etching on metal to porcelain bond strength are lacking.

PURPOSE

The purpose of this in vitro study was to determine the effect of Nd:YAG laser etching on the surface roughness and wettability of and the porcelain bond strength to cobalt chromium (Co-Cr) substrate fabricated by milling and direct metal laser sintering (DMLS).

MATERIAL AND METHODS

Thirty-two 0.5×3×25-mm Co-Cr specimens were fabricated by milling soft Co-Cr (M group) and DMLS Co-Cr metal powder (DML group). The surface topography of representative specimens from each study group was assessed under a scanning electron microscope (SEM) and an atomic force microscope (AFM). All specimens were assessed for surface roughness using a contact profilometer, and for wettability with a contact angle goniometer. Half of the specimens of each study group (n=8) were subjected to surface laser etching by using a Nd:YAG laser. The specimens subjected to etching were assessed again for surface topography and wettability. All specimens in both study groups were veneered with porcelain. The porcelain bond strength was tested with a 3-point bend test in a universal testing machine. The results were statistically analyzed with 2-way ANOVA test followed by the post hoc Tukey test for pairwise comparisons (α=.05).

RESULTS

After etching, the M group had a higher mean ±standard deviation Ra and Rz of 2.9 ±0.6 and 17.7 ±3.2 µm and significantly better wettability and bond strength of 79 ±6 and 52 ±13 MPa. In contrast, after etching, the DMLS group had a significantly lower Ra and Rz of 7.9 ±2.4 and 41.8 ±9.3 µm and significantly lower wettability and bond strength of 87 ±4 and 70 ±10 MPa. The DMLS group had a significantly higher roughness and bond strength than the M group before and after laser etching. The SEM and AFM showed different surface topography in the study groups.

CONCLUSIONS

The manufacturing process of Co-Cr substrate had a significant effect on surface characteristics and porcelain bond strength. Laser etching improved the surface topography and bond strength of milled Co-Cr but not of DMLS Co-Cr.

Survival of tooth-implant connections: A systematic review and meta-analysis

Implant-supported prostheses have considerable biomechanical advantages in partially edentulous patients when compared to other prosthetic options. Given the steady drop in the frequency of patients reporting with complete edentulism, it is not unusual to see situations where teeth and implants can be splinted to provide support for fixed prostheses. A tooth implant prosthesis differs majorly from an implant-supported prosthesis in terms of force dissipation and design. The aim of this systematic review was to compare the survival rates of tooth-implant-supported prostheses with fully implant-supported and fully tooth-supported prostheses. Using the appropriate search terms, PubMed, Google Scholar, and other indexed journals were used to search the English-language literature. According to the review protocols and the PICOS inclusion criteria, the pertinent studies were chosen. The screening of appropriate studies, evaluation of study quality, and data extraction were carried out independently by two reviewers. The pooling of survival data by prostheses failure, implant failure, and marginal bone loss was used in the meta-analysis. The cumulative data of all included studies indicated that tooth-implant-supported prostheses showed a 5-year survival rate of 77%-84% and a 10-year survival rate of 72%. The pooled risk ratio for prostheses failure and implant failure was 0.99 and 1.76, respectively. These results were not statistically significant (P > 0.05). The pooled standard mean difference for marginal bone loss was 0.59, and the results were statistically significant (P < 0.05). A tooth-implant-supported fixed partial denture (FPD) has a similar survival rate when compared to implant-supported FPD or T-FPD.

Treatment alternatives for the rehabilitation of the posterior edentulous maxilla

Rehabilitation of the edentulous maxilla with implant-supported fixed dental prostheses can represent a significant clinical challenge due to limited bone availability and surgical access, among other factors. This review addresses several treatment options to replace missing teeth in posterior maxillary segments, namely the placement of standard implants in conjunction with maxillary sinus floor augmentation, short implants, tilted implants, and distal cantilever extensions. Pertinent technical information and a concise summary of relevant evidence on the reported outcomes of these different therapeutic approaches are presented, along with a set of clinical guidelines to facilitate decision-making processes and optimize the outcomes of therapy.

Satisfaction and preferences among patients with both implant-supported single crown and tooth-supported fixed dental prosthesis: a pilot study

OBJECTIVE

The objective of the study was to assess patient-reported preferences and outcomes in patients rehabilitated with both an implant-supported single crown (ISC) and a tooth-supported fixed dental prosthesis (FDP).

MATERIALS AND METHODS

The electronic journal system at the Faculty of Dentistry, University of Oslo, was searched to find patients presenting both an ISC and an FDP replacing no more than two teeth between abutments. Identified patients that agreed answered a questionnaire followed by a clinical examination. Descriptive statistics was calculated.

RESULTS

Thirty patients were included. The mean function time was 11.8 years for FDPs and 6.6 years for ISCs. All but three patients were satisfied with both rehabilitation modalities. No patients were unsatisfied with aesthetics or function of either rehabilitation. All patients reported satisfactory function of their restorations and reported chewing without problems. The self-reported post-operative complications were few, but less than observed in the clinical examinations.

CONCLUSIONS

More patients reported food impaction with their FDP as compared to their ISC. Function and aesthetics of FDPs and ISCs were rated similarly, but more patients found the ISC treatment more uncomfortable. Despite this finding, most patients would prefer to undergo ISC treatment if they were to replace another missing tooth.

Is the Diagnosis of Generalized Stage IV (Severe) Periodontitis Compatible with the Survival of Extended Stabilizing Prosthetic Restorations? A Medium-Term Retrospective Study

The aim of the study was to identify the most relevant patient-related factors directly involved (alone or in combinations) in the long-term survival and functionality of the abutment teeth of extensive stabilizing bridges and removable prosthesis, in patients treated for Stage IV periodontitis, adhering to SPT over a period of at least 5 years. Seventy-six patients treated between 2000-2022, rehabilitated with FDPs and RDPs, adhering to SPT for at least 5 years were included. Patient-related factors influencing retention of RDPs and FDP, survival rates in regular (RCs) and irregular compliers (ICs), and incidence of biological and technical complications were assessed. During a follow-up of 69 months, from 57 patients with FDPs and 19 patients with RDPs, 39 (51.32%) were ICs, while 37 (48.68%) were RCs. An overall statistically significant association (p = 0.04) was identified between biological complications and the type of prostheses. The RDP patients had more complications than FDP patients. In 5.26% of the RDP patients, root caries were identified, and 10.53% were diagnosed with a periapical (endodontic) lesion, while 3.51% of the FDPS patients presented root caries. In five (6.57%) cases, abutment loss resulted in the loss of the prosthesis. Statistically significant correlations were observed between systemic diseases and tooth loss, and between type of tooth lost and the reason for tooth loss, irrespective of the type of prosthesis. A total of 66.67% of the lost incisors, 85.71% of the lost premolars, and 88.89% of the lost molars occurred due to periodontal causes. Furthermore, 93% of the FDPs and RDPs were still in place and in function.

Survival and complications of implant-supported cantilever fixed dental prostheses with zirconia and metal frameworks: A retrospective cohort study

BACKGROUND

Current evidence about long-term survival of all-ceramic implant-supported cantilever fixed dental prostheses (cFDP) is limited.

PURPOSE

To evaluate the survival and complication rates of all-ceramic and metal-ceramic implant-supported cFDPs located in anterior and posterior sites, under consideration of risk factors.

METHODS OF STUDY

The retrospective analysis compared an experimental group (75 implant-supported cFDPs among 48 patients [mean age 60.47 ± 9.25 years; 21 men]; mean observation period 3.56 years) with a control group (300 implant-supported non-cantilever FDPs [ncFDP] among 241 patients [mean age 62.85 ± 10.72 years; 109 men]; mean observation period 7.25 years). Kaplan-Meier estimates were used to describe the long-term survival and success of both groups. Log-rank tests were used for group comparisons. Mixed-effects Cox proportional hazards regression models were used to examine the effects of restoration- and site-specific risk factors. A random intercept was included in the models to take multiple FDPs per patient into account.

RESULTS

Five-year cumulative survival until loss of restoration was 97.1% (95% confidence interval [CI] 0.93-1.00) for cFDPs and 97.0% (95% CI 0.95-0.99) for ncFDPs. Ten-year survival was 93.7% (95% CI 0.86-1.00) for cFDPs and 92.8% (95% CI 0.87-0.98) for ncFDPs, no difference between the survival curves of these groups was observed. Success differed between cFDPs and ncFDPs (p_Log  = 0.002), zirconia and metal frameworks (p_Log  < 0.001), and provisional and definitive cements (p_Log  = 0.025). The effects of the variables "framework material" and "attachment method" were confirmed in a mixed-effects Cox regression model. Loss of retention was the predominant complication for both cFDPs and ncFDPs and usually affected provisionally cemented FDPs.

CONCLUSIONS

cFDPs do not differ from ncFDPs with regard to long-term failure, whereas additional complications were higher for cFDPs. Fewer complications were observed for zirconia frameworks without occlusal veneers and definitive cemented FDPs.

CLINICAL TRIAL REGISTRATION

the trial has no registration number because it commenced before January 31, 2017.

Influence of Digital Technologies and Framework Design on the Load to Fracture of Co-Cr Posterior Fixed Partial Denture Frameworks

PURPOSE

To compare the load to fracture of cobalt-chromium (Co-Cr) 3-unit posterior fixed partial denture (FPD) frameworks manufactured by conventional and digital techniques and to evaluate the influence of the framework design on the fracture load.

MATERIAL AND METHODS

Eighty 3-unit Co-Cr posterior FPD frameworks were fabricated with two designs: intermediate pontic (n = 40) and cantilever (n = 40). Each design was randomly divided into four groups (n = 10): casting, direct metal laser sintering, soft metal milling, and hard metal milling. After thermal cycling, all specimens were subjected to a 3-point bending test until fracture. Data were statistically analyzed using one-way ANOVA, Welch and Brown-Forsythe test, Ryan-Einot-Gabriel-Welsch F and Tamhane T2 post hoc test, Student's t test, and Weibull statistics (α = 0.05).

RESULTS

Significant differences (p < 0.001; F = 39.59) were found among intermediate pontic frameworks (except between laser sintering and hard metal milling), and cantilevered frameworks (F = 36.75) (except between laser sintering and hard metal milling, and casting and soft metal milling). The cantilever groups showed load to fracture values significantly lower than those of the intermediate pontic (p < 0.001; F = 28.29). The Weibull statistics corroborated the results.

CONCLUSIONS

Hard metal milling and laser sintered frameworks exhibited the highest load to fracture values. However, all tested frameworks demonstrated clinically acceptable load to fracture values. The framework design directly affected the fracture load, with drastically lower values in cantilevered frameworks.

Efficacy and risks of tooth-supported prostheses in the treatment of partially edentulous patients with stage IV periodontitis. A systematic review and meta-analysis

AIM

The aim was to evaluate the efficacy and effectiveness of tooth-supported fixed prostheses in partially edentulous patients with stage IV periodontitis.

MATERIAL AND METHODS

Randomized and controlled clinical trials (RCTs and CCTs) and prospective/retrospective cohort studies or case series were searched in three databases. Survival rate of abutment teeth was considered the primary outcome. Meta-analyses were performed whenever possible.

RESULTS

Twenty-four publications were included. No RCTs or CCTs compared the efficacy of tooth-supported fixed prostheses between patients with severe periodontitis or non-periodontitis patients. Most of the data retrieved were derived from case series. The incidence of abutment-tooth loss after a follow-up period from 2 to 35.4 years was low (n = 17 studies; weighted mean incidence (WMI) = 4.8%; confidence interval (CI) [3.2, 6.5]). The corresponding figure for prostheses failure was WMI = 6.9% (n = 18; 95% CI [4.1, 9.7]). Technical complications seemed to be more frequent than biological complications (caries, endodontic failure, root fracture, etc.). Periodontal outcomes tended to remain stable over time.

CONCLUSION

Tooth-supported fixed prostheses seemed to be a valid treatment approach to restore masticatory function in patients with stage IV periodontitis once periodontal therapy has been accomplished. However, the comparative efficacy of this treatment among periodontitis and non-periodontitis patients is unclear due to the absence of clinical trials.

Adhesion of veneering porcelain to cobalt-chromium dental alloys processed with casting, milling, and additive manufacturing methods: A systematic review and meta-analysis

STATEMENT OF PROBLEM

Selective laser melting (SLM) additive manufacturing (AM) technologies provide an alternative to conventional casting and milling procedures in fabricating metal-ceramic dental prostheses. However, the quality of porcelain bond strength to the SLM AM cobalt-chromium (Co-Cr) metal framework of a dental restoration is unclear.

PURPOSE

The purpose of this systematic review and meta-analysis was to identify in vitro studies that reported the porcelain bond strength to SLM AM Co-Cr dental metal alloys and compare the porcelain bond strength values to cast, milled, and additively manufactured Co-Cr dental alloys.

MATERIAL AND METHODS

An electronic systematic review was performed in different databases: MEDLINE/PubMed, EMBASE, World of Science, Cochrane, and Scopus. A manual search was also conducted. Studies that reported the porcelain bond strength to SLM Co-Cr metal alloys and in the English language were included. Two investigators evaluated the quality assessment of the studies by applying the JBI critical appraisal checklist for quasi-experimental studies (nonrandomized experimental studies). A third investigator was consulted to resolve lack of consensus. Two subgroups were created based on the test used, 3-point bend and shear bond strength tests. The porcelain bond strength of cast, milled, and AM Co-Cr dental alloys were compared. The I2 statistic and its associated P value were used to assess the heterogeneity between studies. The Eger test was used for determining significance of the funnel pots.

RESULTS

A total of 216 studies were collected from the electronic and manual searches. After independently evaluating the titles and abstracts by the reviewers, 26 articles were identified. Three of these were excluded after full-text revision. The porcelain bond strength comparison between the cast and AM alloys for the 3-point bend subgroup revealed a significant result for overall effect (P<.001) favoring the SLM method with considerable heterogeneity (I2=83%, P<.001). Furthermore, the porcelain bond strength comparison between cast and milled alloys for the shear bond strength subgroup revealed a significant test for overall effect (P=.04) favoring milled procedures with a nonsignificant unimportant heterogeneity (I2= 0%, P<.47) and for the 3-point bend subgroup (P<.001) favoring milled specimens with a significant considerable heterogeneity (I2=79%, P<.001).

CONCLUSIONS

The metal manufacturing method had no effect on the porcelain bond strength to Co-Cr dental metal alloys.

Restoration of gingival recession with periodontal preformed composite veneers

Recovery from periodontal disease is not completed until the esthetic sequelae of the disease have been restored. This paper introduces a new technique to restore the natural appearance of the smile in a periodontal patient in a single appointment.

Survival and complication rates of tooth-implant versus freestanding implant supporting fixed partial prosthesis: a systematic review and meta-analysis

PURPOSE

This systematic review was performed to compare tooth, implant and prosthesis failures and biological and technical complications in toothimplant vs freestanding implant supported fixed partial prostheses, in order to evaluate the effectiveness and predictability in combining teeth and implants in the same fixed partial prosthesis.

STUDY SELECTION

A comprehensive and systematic literature research was conducted, according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) statement, to identify human trials, with a minimum sample size of 10 patients, comparing tooth-implant to freestanding implant supported fixed partial prostheses. Four groups of meta-analyses were performed based on the patients treated with toothimplant vs freestanding implant-supported fixed partial prostheses: abutment failures, biological and mechanical complications, prosthesis failures, and prosthetic (technical) complications.

RESULTS

The search yielded 749 records, after removal of duplicates. Based on the title assessment, the abstracts reading and the full-texts evaluation, 8 articles, published between 1999 and 2013, fulfilled the inclusion criteria and were included in the meta-analysis. The studies included were: 4 controlled clinical trials, 2 prospective and 2 retrospective cohort studies. The meta-analysis revealed no significant difference between tooth-implant and implant-implant supported fixed in the number of abutment (implant or tooth) failures, biological complications, prosthesis lost, and prosthetic complications.

CONCLUSIONS

Within the limitations of the present systematic review, although the freestanding implant supported fixed partial prosthesis remains the first choice, joining teeth and implants to support fixed prosthesis in partially edentulous patients becomes a valid alternative with an acceptable success rate.

Chemical composition, surface roughness, and ceramic bond strength of additively manufactured cobalt-chromium dental alloys

STATEMENT OF PROBLEM

Selective laser melting (SLM) additive manufacturing (AM) technology is a current option to fabricate cobalt-chromium (Co-Cr) metal frameworks for dental prostheses. However, the Co-Cr alloy composition, surface roughness, and ceramic bond strength values that SLM metals can obtain are not well-defined.

PURPOSE

The purpose of this in vitro study was to compare the chemical composition, surface roughness, and ceramic shear bond strength of the milled and SLM Co-Cr dental alloys.

MATERIAL AND METHODS

A total of 50 disks of 5 mm in diameter and 1 mm in thickness were fabricated by using subtractive (control group) and AM with each of following SLM providers: SLM-1 (EOS), SLM-2 (3D systems), and SLM-3 (Concept Laser). The milled disks were airborne-particle abraded with 100-μm aluminum oxide particles. All the specimens were cleaned before surface roughness (Ra), weight (Wt%), and atomic (At%) percentages were analyzed. Three-dimensional profilometry was used to analyze the topographical properties of the surface parameters Ra (mean surface roughness). The chemical composition of Co-Cr alloy specimens was determined by using energy dispersive X-ray (EDAX) elemental analysis in a scanning electron microscope (SEM). Thereafter, the specimens were bonded to a ceramic (Dentine A3 and Enamel S-59; Creation CC) interface. Specimens were stored for 24 hours at 23 °C. The bond strength of the SLM-ceramic interface was measured by using the macroshear test (SBT) method (n=10). Adhesion tests were performed in a universal testing machine (1 mm/min). The Shapiro-Wilk test revealed that the chemical composition data were not normally distributed. Therefore, the atomic (At%) and weight percentages (Wt%) were analyzed by using the Kruskal-Wallis test, followed by pairwise Mann-Whitney U tests between the control and AM groups (AM-1 to AM-4). However, the Shapiro-Wilk test revealed that the surface roughness (Ra) and ceramic bond strength data were normally distributed. Therefore, data were analyzed by using 1-way ANOVA, followed by the post hoc Sidak test (α=.05).

RESULTS

Significant differences were obtained in Wt%, At%, and Ra values among the Co-Cr alloys evaluated (P<.05). Furthermore, the control group revealed significantly lower mean ±standard deviation Ra values (0.79 ±0.11 μm), followed by AM-3 (1.57 ±0.15 μm), AM-2 (1.80 ±0.43 μm), AM-1 (2.43 ±0.34 μm), and AM-4 (2.84 ±0.27 μm). However, no significant differences were obtained in the metal-ceramic shear bond strength among the different groups evaluated, ranging from mean ±standard deviation 75.77 ±11.92 MPa to 83.65 ±12.21 MPa.

CONCLUSIONS

Co-Cr dental alloys demonstrated a significant difference in their chemical compositions. Subtractive and additive manufacturing procedures demonstrated a significant influence on the surface roughness of the Co-Cr alloy specimens. However, the metal-ceramic shear bond strength of Co-Cr alloys was found to be independent of the manufacturing process.

Clinical performance of zirconia-ceramic cantilever fixed partial dentures-Longitudinal nine-year results from a prospective, randomized, controlled pilot study

PURPOSE

The aim of this study was to prospectively compare the clinical performance of veneered zirconia cantilever fixed partial dentures (Z-CFPDs) and metal-ceramic CFPDs (MC-CFPDs) over 9 years of follow-up in terms of survival.

METHODS

Twenty-one participants were assigned by simple randomization to receive either 1 Z-CFPD (n=11) or 1 MC-CFPD (n=10). CFPDs were retained by 2 full crowns and replaced a missing premolar or a central or lateral incisor. Modified USPHS (United States Public Health Service) criteria were used to classify material chipping, retention, marginal integrity, secondary caries, and color of the restorations. The satisfaction of the study participants with the esthetics of their restorations was surveyed; pocket probing depths (PPD), plaque index (PI), and gingival index (GI) were also measured. Study groups were compared by use of U tests (continuous variables), or by use of Fisher exact probability tests (categorical variables) with α=0.05.

RESULTS

Sixteen participants (n=8 with a Z-CFPD and n=8 with an MC-CFPD) attended the 9-year follow-up examination (response rate: 76.2%). Over the 9-year study period, survival of 50% for Z-CFPDs and 75% for MC-CFPDs was recorded (p=0.608). No framework fractures occurred, and no statistically significant differences were observed between the groups regarding changes in PPD, PI, GI, or participant satisfaction (p>0.05). USPHS criteria revealed statistically significantly poorer marginal quality for Z-CFPDs than for MC-CFPDs (p=0.009).

CONCLUSION

Within the limitations of this study, Z and MC-CFPDs demonstrated no statistically significant difference in terms of survival.

Factors affecting the complexity of dental implant restoration - what is the current evidence and guidance?

Objectives The aim of this paper is to identify the factors that affect the complexity of implant restoration and to explore the indices that help us to assess it. With this knowledge the growing number of clinicians restoring dental implants will have a better understanding of the available guidance and evidence base, and the differing levels of competence required.Study design A literature review was conducted. The selection of publications reporting on complexity was based on predetermined criteria and was agreed upon by the authors. After title and abstract screening 17 articles were reviewed. The articles that were utilised to form the ITI SAC tool and Cologne Risk Assessment we also included.Assessing complexity Two key guides are available: International Team for Implantology's Straight-forward Advanced Complex tool and the Cologne ABC risk score. While these guides help identify treatment complexity they do not provide a strong enough evidence base from which to solely base clinical decisions. The key patient factors are expectation, communication, the oral environment, aesthetic outcome, occlusion, soft tissue profile and the intra-arch distance, whereas the key technical factors are impression taking, type of retention, loading protocol and the need for provisional restorations. Human factors also have a significant effect on complexity, specifically, the experience and training of the clinician, team communication and the work environment.Conclusions There are many interconnecting factors that affect the complexity of dental implant restoration. Furthermore the two widely used indices for the assessment of complexity have been investigated, and although these offer a good guideline as to the level of complexity, there is a lack evidence to support their use. The development of evidence-based treatment and protocols is necessary to develop the current indices further, and these need to be expanded to include other critical areas, such as human factors. A practical guide to aid practitioners in reducing complexity has been proposed.

Effect of history of periodontitis on implant success: meta-analysis and systematic review

PURPOSE

To determine if there is a relationship between history of periodontitis and dental implant success (used marginal bone loss [MBL] as the assessment criteria) and survival rates.

MATERIALS AND METHODS

PubMed search was performed in the period between 2002 and 2012. Studies qualified for the inclusion should have ≥5 years followed-up and reported the incidence of peri-implantitis and/or implant survival and/or MBL in patients with and without a history of periodontitis. A meta-analysis was performed using the random-effects model on the selected qualified articles.

RESULTS

All the 14 studies showed better implant survival rates for non-periodontitis patients' group. Six of 10 studies reported statistically significantly higher MBL and prevalence of peri-implantitis among periodontitis patients. Our meta-analysis did not find implant survival rates to be significantly lower among periodontitis patients (P = 0.99) but revealed a history of periodontitis to be significantly related to the higher prevalence of peri-implantitis (P < 0.001).

CONCLUSIONS

There is no difference, in terms of implant survival rate, between periodontitis and non-periodontitis patients. However, patients with history of periodontitis had lower implant success rate (more MBL and incidence of peri-implantitis) when compared with non-periodontitis patients.

Periodontal and peri-implant microbiota in patients with healthy and inflamed periodontal and peri-implant tissues

OBJECTIVE

To compare the prevalence and levels of six bacterial pathogens within the subgingival/submucosal microbiota at teeth versus implants with various clinical conditions.

MATERIAL AND METHODS

Twenty-two Chinese were included. Four subgingival/submucosal sites were selected for microbiological sampling within each subject, that is, (1) healthy peri-implant tissues; (2) peri-implantitis [PPD ≥ 5 mm, presence of bleeding on probing (BOP) and confirmed radiographic bone loss]; (3) healthy gingiva; and (4) periodontitis (PPD ≥4 mm). Subgingival/submucosal plaque was sampled using paper points. Quantitative real-time polymerase chain reaction (q-PCR) was used to quantify six pathogens, including Porphyromonas gingivalis (P.g.), Treponema denticola (T.d.), Aggregatibacter actinomycetemcomitans (A.a.), Fusobacterium nucleatum (F.n.), Prevotella intermedia (P.i.), and Staphylococcus aureus (S.a.). Counts were log10-transformed.

RESULTS

The most commonly detected species were S. a. and F. n., while A. a. and. P. i. had the lowest detection frequency. The detection frequencies of diseased tooth or implant sites for each of the six target species were either equal to or higher than the respective frequencies at the corresponding healthy sites. There were no statistically significant differences for any of the species or clinical sites (P > 0.05, Cochran's Q test). No statistically significant differences in the bacterial loads were found among the four clinical sites; with the exception of F. nucleatum. This was more abundant in periodontitis sites (P = 0.023, Friedman's 2-way anova). Both periodontal and peri-implant sites, irrespective of their health status, were revealed to harbor S. aureus cells. The log10-transformed loads of S. aureus were approximately 3.5 within each of the clinical sites (P = 0.232). This was the highest of the six species analyzed.

CONCLUSIONS

Within the same subjects, putative periodontal pathogens were common to both periodontal and peri-implant sites irrespective of health status. The prevalence and levels of P. gingivalis and F. nucleatum were significantly associated with periodontitis, but not with peri-implantitis. A. actinomycetemcomitans was associated with both disease conditions, periodontitis and peri-implantitis, but not with either gingival or mucosal health.

A systematic review of outcome measurements and quality of studies evaluating fixed tooth-supported restorations

PURPOSE

The purpose of this systematic review was to review clinical studies of fixed tooth-supported prostheses, and to assess the quality of evidence with an emphasis on the assessment of the reporting of outcome measurements. Multiple hypotheses were generated to compare the effect of study type on different outcome modifiers and to compare the quality of publications before and after January 2005.

MATERIALS AND METHODS

An electronic search was conducted using specific databases (MEDLINE via Ovid, EMBASE via Ovid, Cochrane Library) through July 2012. This was complemented by hand searching the past 10 years of issues of the Journal of Oral Rehabilitation, Journal of Prosthetic Dentistry, Journal of Prosthodontics, and the International Journal of Prosthodontics. All experimental and observational clinical studies evaluating survival, success, failure, and complications of tooth-supported extracoronal fixed partial dentures, crowns, and onlays were included. No restrictions on age or follow-up time were placed.

RESULTS

The electronic search generated 14,869 papers, of which 206 papers were included for full-text review. Hand-searching added 23 papers. Inclusion criteria were met by 182 papers and were included for the review. The majority were retrospective studies. Only 8 (4.4%) were randomized controlled trials. The majority of the studies measured survival and failure, and few studies recorded data on success; however, more than 60% of the studies failed to define survival, success, and failure. Many studies did not use any standardized criteria for assessment of the quality of the restorations and, when standardized criteria were used, they were modified, thereby not allowing for comparisons with other studies. There was an increase of 21.8% in the number of studies evaluating outcome measurements of all-ceramic restorations in past 8 years.

CONCLUSIONS

Prosthodontic literature presents with a reduced percentage of RCTs compared to other disciplines in dentistry. The overall quality of recording prosthodontic outcome measurements has not improved greatly in the past 8 years.

Esthetic treatment of a periodontal patient with prefabricated composite veneers and fiber-reinforced composite: clinical considerations and technique

The advances in periodontal therapy and the clinical success of adhesive dentistry have changed the way dentists treat periodontal patients. As more teeth are saved, the demand for functional and esthetic restoration of periodontally involved teeth grows. Once, these teeth were restored with full-coverage splinted restorations, whereas today, adhesive techniques provide less invasive and less complicated treatment options. This paper presents a novel adhesive combination of fiber-reinforced composite and prefabricated composite veneers to restore function and esthetics in a periodontal patient with severe bone and attachment loss. After successful completion of the periodontal treatment, fiber-reinforced composite has been bonded to the buccal surface of the maxillary anterior teeth in order to control teeth mobility. At the same appointment, prefabricated composite veneers have been bonded to the splinted teeth in order to restore esthetics. The final result shows full integration of contemporary adhesive techniques for single-appointment, minimally invasive treatment of a periodontal patient.

CLINICAL SIGNIFICANCE

This paper describes the use of fiber-reinforced composite and prefabricated composite veneers for the treatment of severe periodontal patients with a minimally invasive, single-appointment technique.

Common Post-fitting Complications in Tooth-supported Fixed-Fixed Design Metal-Ceramic Fixed Dental Prostheses

Objectives: To report the frequency of common complications and their levels in metal-ceramic fixed dental prostheses (MC-FDPs).

Methods: A Descriptive Cross-sectional study was conducted at the Prosthodontics Department, Khyber College of Dentistry Peshawar from January 2011 to October 2012. Using a structured proforma, data from 139 subjects fulfilling the inclusion and exclusion criteria for the study and reporting complications in their MC- FDPs were collected using the method of interview, clinical & radiographic examination.

Results: Of 139 subjects (Mean age = 34+ 6.4 Years), 81 (58.3%) were males and 58 (41.7%) were females with a male to female ratio of 1.4:1. De-cementation was the most common complication (41.7%). Least common complication was secondary caries (6.5%). Level-1 complications were more prevalent (77.7%) than level-2 complications (22.3%). In 91.4% cases, complications occurred before the FDP completed their fifth-years’ service life with 25.2% of these occurring within the first years’ service life.

Conclusion: Irrespective of the type of complications, level-1 complications were more common with de-cementation being the most common complication. One-quarter of all the complications occurred within the first-year service life of the FDPs highlighting concern over the quality of the provided MC-FDPs. .

Evaluation of bacterial adhesion on machined titanium, Osseotite® and Nanotite® discs

PURPOSE

Bacterial adhesion and colonization play a crucial function in the pathogenesis of peri-implant tissue infection, which is considered the main cause of fixture loss. The aim of this study is to evaluate the differences in bacterial adhesion between a machined titanium surface, a double acid etched surface (Osseotite®) and an Osseotite surface with Nanometer-scale Discrete Crystalline Deposition (DCD™) of calcium phosphate (CaP)(Nanotite®).

METHODS

Surface roughness properties of each sample were determined by a laser profilometer and scanning electron microscopy (SEM) observation. Bacterial adhesion on machined, Osseotite®, and Nanotite® discs were performed using the following bacterial strains: Streptococcus mutans CCUG 35176, Streptococcus sanguis CCUG 17826, Streptococcus salivarius CCUG 11878, Actinobacillus actinomycetecomitans CCUG 37002, Porphyromonas gingivalis CCUG 2521. The assessment of bacterial adhesion was performed by comparing two methods: Total Viable Count (TVC) estimation and Confocal Laser Scanning Microscopic (CSLM) studies.

RESULTS

The surface roughness parameter increased as follows: machined<Nanotite®<Osseotite®. The attachment of all bacterial strains performed by both methods showed a significant reduction on Osseotite® and even higher on Nanotite® in comparison to machined surfaces (p<0.05). The reduction in bacterial attachment was more significant on Osseotite® and Nanotite® for A. actinomycetecomitans, S. mutans and S. sanguis than for P. gingivalis and S. salivarius strains.

CONCLUSIONS

Nanotite® samples showed the lowest amount of bacterial contamination in comparison to the smoother machined and rougher Osseotite® surfaces.

The impact of cantilevers on biological and technical success outcomes of implant-supported fixed partial dentures. A retrospective cohort study

OBJECTIVE

To investigate the biological and technical success outcomes of implant-supported fixed dental prostheses with and without cantilevers, after a minimum of one year loading.

MATERIAL AND METHODS

One hundred and seven subjects with 128 cantilever FDPs (cFDP) supported by 132 implants were compared with 99 individuals with 144 non-cantilever FPDs (ncFDPs) supported by 203 implants. Outcomes such as marginal bone loss from FDP insertion to final follow-up as well as frequency and extent of biological and technical complications were investigated and correlated with patient, site, implant and FDP design characteristics.

RESULTS

The cFDPs were followed for average of 51 months (1551 days, SD ± 977), and ncFPDs for 49 months (1483 days, SD ± 809 days). Implant survival and success rates were 96.7% and 87.9% for implant supporting cFDPs, and 99.5% and 92.6% for ncFDPs. There was no significant difference in overall bone loss between cFDPs and ncFDPs (cantilever side: 0.58, SD ± 1.16 - non-cantilever side: 0.59, SD ± 0.99), but implants in the cantilever group lost significantly more bone in the posterior mandible (0.50 SD ± 1.3 mm for cFDPs and 0.24 SD ± 0.80 mm for ncFDPs). Within the cantilever group, cantilever arm length and implant location had an influence on bone loss. Regardless of the presence of cantilever, implants associated with technical complications had a higher rate of biological complications as well. Furthermore, the length of the cantilever arm was positively correlated with implant failure, technical complications and bone loss ≥1.5 mm (P = 0.011, <0.001, and 0.007).

CONCLUSION

Overall implants can be successfully used to support cantilever FDPs. However, there are technical and biological implications which appear inter-related.

Oral rehabilitation considerations for partially edentulous periodontal patients

Traditional tooth-supported and implant-supported fixed/removable restorations are currently used to replace teeth lost due to periodontal disease. This article reviews the existing literature for oral rehabilitation of partially edentulous periodontal patients with various designs of removable dental prosthesis (RDP), fixed dental prosthesis (FDP) and implant-supported single crown (SC), by addressing their (a) general features, (b) survival and complication rates, along with considerations for treatment planning in periodontal patients, and (c) preference by patients. To answer these issues, relevant articles were searched and critically analyzed, and their data were extracted. Data reviewed indicated that despite many advantages, implant-supported restorations have higher complication rates than tooth-supported restorations. Systematic reviews on conventional RDPs are lacking, but existing literature reviews provide limited evidence suggesting the use of RDPs with design modifications along with strict periodontal care in periodontal patients. Numerous systematic reviews on conventional FDPs and implant-supported restorations provide a moderate level of evidence favoring their survival in periodontal patients; however, for long-term success of these restorations, the patient's periodontal condition needs to be stabilized. In terms of patient preference, no restoration is superior, as they all are governed by their cost, advantages, and disadvantages. Thus, in the wake of existing weak evidence for prosthodontic rehabilitation of periodontal patients by these restorations (especially, conventional RDPs and for FDPs and SCs in implant-supported restorations), longitudinal studies with standardized treatment protocol and methodology are needed to evaluate and compare tooth-supported and implant-supported restorations in periodontal patients with regard to survival rates, cost, maintenance, and patient-centered outcomes.

Clinical and radiographic changes at implants supporting single-unit crowns (SCs) and fixed dental prostheses (FDPs) with one cantilever extension. A retrospective study

OBJECTIVES

To evaluate the clinical and radiographic changes at implants in posterior maxillary and mandibular areas supporting single-unit crowns (SCs) and fixed dental prostheses (FDPs) with one mesial or distal cantilever extension after an observation period of at least 3 years.

MATERIAL AND METHODS

Seventeen subjects with 19 implant-supported SCs and 21 subjects with 21 implant-supported FDPs fulfilled the inclusion criteria. All FDPs were supported by two implants and had a span of 3-4 units. All reconstructions were incorporated in the posterior maxilla or mandible. The mesial and distal radiographic marginal bone loss from baseline (i.e. delivery of the reconstruction) to the follow-up examination was averaged and compared between SCs supporting one cantilever extension with that of implants supporting FDPs adjacent to or distant from the cantilever extension. Changes in mean pocket probing depth (PPD) were calculated and compared between the three groups.

RESULTS

The mean observation period was 78.2 ± 34.5 months for SCs supported by one implant and 67.8 ± 29.8 months for FDPs supported by two implants. No implant loss occurred, yielding a 100% survival rate. At baseline, the mean radiographic bone levels ± SD were 2.6 ± 0.3 mm for implants supporting SCs, 2.6 ± 0.3 mm for implants of FDPs adjacent to the cantilever extension, and 2.4 ± 0.5 mm for implants of FDPs distant from the cantilever extension. At follow-up, the corresponding mean bone levels ± SD were 2.7 ± 0.4, 2.7 ± 0.5, and 2.8 ± 0.5 mm, respectively. No statistically significant differences (P > 0.05) were observed comparing the mean marginal bone loss between the three groups. Moreover, mean changes in PPD between baseline and follow-up were not statistically significantly different (P > 0.05) between the three groups.

CONCLUSION

The presence of one mesial or distal cantilever extension in the posterior maxilla or mandible does not jeopardize the marginal bone levels of implants supporting SCs or short-span FDPs after a mean observation period of at least 5 years.