Status of Tooth Loss and Denture Restoration in Chinese Adult Population: Findings from the 4th National Oral Health Survey

OBJECTIVE

To investigate the status of tooth loss and denture restoration in Chinese adults, analyse the changing trend and provide fundamental data for oral health policy.

METHODS

According to the protocol of the 4th National Oral Health Survey, a multistage stratified random cluster-sampling method was used to enrol adult subjects aged 35 to 44, 55 to 64 and 65 to 74 years in all 31 provinces, municipalities and autonomous regions of the mainland of China. The status of tooth loss and denture restoration was investigated. SPSS20.0 software was used for statistics analysis.

RESULTS

Among the 13,464 subjects investigated, 13.8% had complete dentition, 84.4% had dentition defects, and 1.8% was edentulous. Urban subjects showed a significantly higher proportion of complete dentition than those in rural (P = 0.02), and males showed the statistically higher proportion of complete dentition than females (P = 0.01). The mean of remaining teeth was 26.1 ± 6.90, which in urban areas was significantly higher than in rural areas (P < 0.01). The means of remaining teeth were 29.6 ± 2.3, 26.3 ± 6.1, and 22.5 ± 8.7 in the 35 to 44, 55 to 64 and 65 to 74 age groups, respectively. The detection rate of fixed partial dentures (FPD) was statistically higher in urban than in rural areas and in males than that in females (P < 0.01). The detection rate of removable partial dentures (RPD) was statistically higher in urban areas than in rural locations (P < 0.01). However, the detection rates of irregular denture and unrepair of tooth loss were both significantly lower in urban than in rural areas (P < 0.01). The rate of restoration of tooth loss was 41.6% in Chinese adults.

CONCLUSION

Although the tooth loss and denture restoration status recorded in the survey was improved compared with the results of 10 years ago, more efforts need to be made on strengthening oral health promotion, particularly for elderly people and those living in rural areas.

Analysis of Vertical Marginal Adaptation of Zirconia Fixed Dental Prosthesis Frameworks Fabricated by the CAD/CAM System: A Randomized, Double-Blind Study

PURPOSE

The purpose of this study was to evaluate the marginal adaptation of fixed dental prosthesis frameworks fabricated by computer-aided design/computer-assisted manufacture (CAD/CAM) with three different systems of data acquisition.

MATERIALS AND METHODS

A total of 50 specimens were fabricated as follows: using the conventional method (Ni-Cr) (n=10); iTero/industrial milling (Group 1, n=10); Cerec Bluecam/industrial milling (Group 2, n=10); 3S/industrial milling (Group 3, n=10); and Cerec BlueCam/Sirona milling (Group 4, n=10). The specimens were numbered and randomized, and the vertical marginal discrepancy was analyzed.

RESULTS

Intraobserver analysis indicated no statistically significant difference (paired t test, P=.822) between periods before and after analysis. The conventional method (321 μm) showed greater discrepancy when compared with the CAD/CAM system (89 μm) (P<.001). The intraoral system showed a lower rate of marginal discrepancy when compared with the extraoral system (3S) (P<.001). The closed system presented a higher marginal discrepancy (114 μm) than the open intraoral system (iTero) at P<.001. In addition, the intraoral system when open showed statistically significant differences in mean marginal discrepancy values compared with the same system in closed condition (P>.05).

CONCLUSION

The CAD/CAM systems showed less marginal discrepancy than the conventional method for the fabrication of the frameworks.

Analysis of Vertical Marginal Adaptation of Zirconia Fixed Dental Prosthesis Frameworks Fabricated by the CAD/CAM System: A Randomized, Double-Blind Study

PURPOSE

The purpose of this study was to evaluate the marginal adaptation of fixed dental prosthesis frameworks fabricated by computer-aided design/computer-assisted manufacture (CAD/CAM) with three different systems of data acquisition.

MATERIALS AND METHODS

A total of 50 specimens were fabricated as follows: using the conventional method (Ni-Cr) (n=10); iTero/industrial milling (Group 1, n=10); Cerec Bluecam/industrial milling (Group 2, n=10); 3S/industrial milling (Group 3, n=10); and Cerec BlueCam/Sirona milling (Group 4, n=10). The specimens were numbered and randomized, and the vertical marginal discrepancy was analyzed.

RESULTS

Intraobserver analysis indicated no statistically significant difference (paired t test, P=.822) between periods before and after analysis. The conventional method (321 μm) showed greater discrepancy when compared with the CAD/CAM system (89 μm) (P<.001). The intraoral system showed a lower rate of marginal discrepancy when compared with the extraoral system (3S) (P<.001). The closed system presented a higher marginal discrepancy (114 μm) than the open intraoral system (iTero) at P<.001. In addition, the intraoral system when open showed statistically significant differences in mean marginal discrepancy values compared with the same system in closed condition (P>.05).

CONCLUSION

The CAD/CAM systems showed less marginal discrepancy than the conventional method for the fabrication of the frameworks.

Three-Year Analysis of Fixed and Removable Telescopic Attachment-Retained Implant-Supported Dental Prostheses: Survival and Need for Maintenance

PURPOSE

The purpose of this retrospective clinical study was to evaluate the clinical outcomes of fixed implant-supported dental prostheses (FISDPs) and removable ISDPs (RISDPs) retained by telescopic attachments, the factors influencing survival, and the type and number of maintenance treatments required during the observation period.

MATERIALS AND METHODS

This retrospective clinical study is based on patients who were provided with ISDPs between 2004 and 2010. Patient sex, type of prosthesis, location, opposing dentition, and the effect of continuous follow-up on the probability of a favorable outcome, as well as the number of maintenance treatments, were analyzed. A statistical analysis was performed using the Kaplan-Meier method.

RESULTS

A sample of 233 patients with 157 FISDPs and 76 RISDPs supported by a total of 567 implants was randomized and included in the analysis. The mean observation period was 15.9 ± 15.4 months (maximum, 66.0 months). During the observation period, 3.9% of prostheses (7/157 FISDPs and 2/76 RISDPs) ceased to function and 2.3% of implants (13 implants) were lost. The mean survival time was 59.7 ± 2.3 months, with a survival probability of 90.2% after 3 years. Prostheses in the mandible showed significantly higher survival rates than those in the maxilla. Maintenance treatments had to be performed at an earlier stage for patients with RISDPs than for patients with FISDPs. In patients with a conventional removable prosthesis in the opposing arch, the time until maintenance was needed was significantly shorter.

CONCLUSION

Within the limitations of a retrospective study, it can be concluded that the FISDPs and RISDPs show equally good survival rates after 3 years in function. RISDPs showed a greater and earlier need for maintenance treatments during the first years in function.

How long will it last? The expected longevity of prosthodontic and restorative treatment

With the Internet facilitating access to vast amounts of free information, dental practitioners face providing treatment for an increasingly informed public. However, the available content is not filtered, and it can be difficult for patients to discriminate between research-informed evidence and "glamorised" material of dubious origin. Patients reasonably expect a return for their investment and want to know how long their treatment will last. Clinicians have an obligation to inform their patients so that they can make reasoned decisions about treatment options. Longevity data are also informative for health agencies setting service schedules for publicly funded treatment, and for determining settlements by insurers such as ACC. Historically, much of the prosthodontic treatment performed in practice has relied heavily on dogma, low-level anecdotal evidence, and clinical case reports. This paper considers the literature on fixed and removable prosthodontic restorations and provides a critical review which can be used practically as the basis for informing patients, and to assist decision-makers in making fair and appropriate judgements.

Does a case completion curriculum influence dental students' clinical productivity?

The purpose of this study was to evaluate the effects of a new clinical curriculum on dental student productivity as measured by number of procedures performed in the student teaching practice. Harvard School of Dental Medicine adopted a new clinical education model for the predoctoral program in summer 2009 based upon a Case Completion Curriculum (CCC) rather than a discipline-based numeric threshold system. The two study groups (threshold group and case completion group) consisted of students who graduated in 2009 and 2010. Clinical performance was assessed by clinical productivity across five major discipline areas: periodontics, operative dentistry, removable prosthodontics, fixed prosthodontics, and endodontics. The relationships between the two study groups with regard to number of procedures performed by category revealed that the case completion group performed a significantly higher number of operative and removable prosthodontic procedures, but fewer periodontal and endodontic procedures (p≤0.03). No statistically significant difference in number of procedures was observed with fixed prosthodontic procedures between the two groups. Clinical productivity as a result of redesigning the clinical component of the curriculum varied in selected disciplines. The CCC, in which the comprehensive management of the patient was the priority, contributed to achieving a patient-based comprehensive care practice.

Tooth loss and oral rehabilitation in Greek middle-aged adults and senior citizens

PURPOSE

The aims of this study were to investigate the prevalence of tooth loss in Greek individuals aged 35 to 44 and 65 to 74 years in relation to sociodemographic parameters and to describe their prosthetic status and needs.

MATERIALS AND METHODS

A stratified cluster sample of 1,188 middle-aged adults and 1,093 senior citizens was selected according to World Health Organization (WHO) guidelines for national pathfinder surveys. Tooth loss and prosthetic status and needs were recorded according to WHO criteria. Sociodemographic data were collected through face-to-face interviews.

RESULTS

Complete edentulism affected 0.3% of individuals aged 35 to 44 years and 31.5% of those aged 65 to 74 years. Most middle-aged adults (92.1%) had ≥ 21 natural teeth, while the corresponding percentage for the senior citizens was 23.1%. The mean number of missing teeth was 5.2 in middle-aged adults and 21.6 in senior citizens. The multivariate analysis showed that education level was the only predictor of tooth loss in both age groups. Approximately 38% of those aged 35 to 44 years and 80% of those aged 65 to 74 years had dental prostheses, while 47.6% of middle-aged adults and 66.3% of senior citizens did not need any prosthetic treatment. The need for complete dentures was relatively low in both age groups. Comparisons of the present results with those of 1985 indicate that the dentate status of Greek adults aged 35 to 44 years has not improved. Furthermore, the prevalence of tooth loss in the elderly population was high compared with internationally reported findings.

CONCLUSION

The replacement of missing teeth with fixed or removable prostheses will continue to be common in Greece for the foreseeable future.

[Dental treatment strategies for elderly patients]

The elderly are influenced from a various and complex combination of factors, such us individual genetic predispositions, lifestyle, society and environment, the sum of all the individual life experiences concerning the dental care, the caries, the periodontal and iatrogenic diseases.

AIM

This paper evaluates the dental treatment in the elderly.

MATERIAL AND METHODS

The study was performed on 112 patients, aged over 65, at the Clinical Department of Dental Semiology und Geriatric Dentistry, Iaşi, Romania.

RESULTS

The treatment interventions were dental hygiene procedures (in 97 patients), restaurations (in 29 patients), removable partial and total denture preocedures (in 50 patients), fixed prosthetic procedures (in 18 patients), rebasing of dentures (in 25 patients) and teeth extractions (in 26 patients). There were 36 endodontic emergencies and 15 periodontal emergencies and 8 emergencies that resulted from other causes.

CONCLUSIONS

The periodical dental examinations and the proper daily oral hygiene routine are still important in the old age and they should not be neglected, because the prosthetical components request also treatment interventions.

Dental alloys used for crown and bridge restorations by dental technicians in New Zealand

OBJECTIVE

To determine the range and elemental composition of alloys used for PFM and crown-and-bridge restorations by New Zealand dental laboratories, and to understand the reasons for their selection.

MATERIALS AND METHODS

Two waves of data collection were carried out via post and telephone interview. The source population was dental laboratories advertised with the Yellow Pages Group in 2007/2008.

RESULTS

A total of 83 out of 109 laboratories (76.1%) responded. Of those, 35 laboratories (42.1%) reported producing fixed-prosthodontic restorations. The range of alloy types (consisting of high noble, noble and base-metal alloys), brand names (55 products) and manufacturers was determined, along with the reasons for their selection. Ten international dental alloy manufacturers were identified as being used, with the leading manufacturer being Ivoclar-Vivadent (40.9%), followed by Argen (25.3%). Most laboratories select their alloys based on price and physical properties. The average laboratory carries three to four alloy products.

CONCLUSION

Alloy selection by dentists and dental technicians is strongly influenced by economic factors. While the study identified the range of alloys being used for fixed restorations in terms of alloy type and brand name, further research is needed to determine the proportions of fixed restorations produced from high noble, noble and base metal alloys, together with dental practitioners' attitudes to, and preferences in, alloy selection.

Demographics of implant placement and complications of a patient subgroup in a dental hospital population

STATEMENT OF PROBLEM

Little has been reported about the demographics of implant placement in the Irish population and the complications that occur. This is important in terms of service planning and providing patient information.

PURPOSE

The purpose of this study was to construct a database of patients who had implants placed in the Dublin Dental School et Hospital from 2000 to 2006. Also, we wanted to compare the complications that occurred in patients who had overdentures to those with a fixed prosthesis.

METHODS

Hospital records were searched for all patients who had implants placed over a seven-year period and we recorded demographic information, as well as details of the implant site, implant type and restoration. Patients who had four or more implants placed for an implant-supported overdenture or fixed prosthesis were invited to attend for a clinical examination.

RESULTS

A total of 1,111 implants were placed in 452 patients over the study period--half of the implants supported single crowns, while the other half supported mainly overdentures and full arch fixed prostheses, with few fixed partial dentures. The 40- to 60-year-olds had the greatest number of implants placed of any age group and most implants were placed in the anterior region. Patients with implant-supported overdentures recorded more complications (52%) compared to those with fixed prostheses (32%). The most common complications associated with both treatments were gingival inflammation and peri-implant mucositis. Overdentures additionally had a significant number of retentive clip fractures.

CONCLUSIONS

Implant-supported overdentures and fixed prostheses were both clinically successful. However, patients and clinicians should be aware that soft tissue and mechanical complications are common.

Prospective evaluation of zirconia posterior fixed partial dentures: four-year clinical results

PURPOSE

In this prospective clinical study, the performance of three- and four-unit fixed partial dentures (FPDs) with frameworks fabricated of yttria partially stabilized zirconia was determined after a mean observation period of 50 months. The study focused on the survival of the restoration (in situ criterion) and the success of the ceramic veneers (no defect).

MATERIALS AND METHODS

Seventy-five patients with a maximum of two missing teeth and an antagonistic dentition were treated at the Department of Prosthodontics, University of Goettigen, with 99 posterior FPDs. Fifty-one specimens (experimental group) were veneered with an experimental ceramic suitable for titanium and zirconia frameworks (thermal expansion coefficient [TEC]: 8.5 microm/m*K); 48 restorations (Ceram-S group) were veneered with a commercially available low-fusing ceramic optimized for zirconia frameworks (TEC: 9.5 microm/m*K). All restorations were luted with zinc-phosphate cement. Statistical analysis was performed according to the Kaplan-Meier method; time-dependent success rates of the different types of ceramic veneers were analyzed using the log-rank test.

RESULTS

Seven restorations were lost: 4 due to technical complications and 3 due to biologic complications. The overall survival rate after 48 months was 94% (Kaplan-Meier analysis). Twenty-three events required clinical intervention for restoration maintenance: 13 ceramic veneer chippings (polishing), 6 losses of retention (recementation), 3 caries lesions (filling therapy), and 1 loss of vitality (endodontic treatment). Between the two groups of veneering materials, no significant difference in the probability for success was determined (log-rank test, P=.81).

CONCLUSIONS

Within a mean observation period of 4 years, sufficient survival rates for zirconia-based posterior FPDs could be verified. The main complications included fracture of the ceramic veneering material and decementation, which occurred mainly in the mandible.

Outcomes of root canal treatment in Dental Practice-Based Research Network practices

This study sought to quantify the incidence of root canal treatment (RCT) failure and identify its predictors in root canals that were performed or referred by general dentistry practices in a practice-based research network (PBRN). This retrospective cohort study involved 174 endodontically treated teeth. Mean duration from initial therapy to follow-up was 8.6 years. Permanent restorations were ultimately placed in 89% of teeth, although 18% of teeth were ultimately extracted anyway. Receiving a permanent restoration was a significant predictor of treatment failure (in other words, patients who did not receive a permanent restoration were more likely to experience RCT failure), whether failure was determined clinically or radiographically. This study of PBRN practices suggests a higher failure rate compared with studies that utilized highly controlled environments or populations with high levels of dental insurance.

Replacement of missing teeth in a southern region of Vietnam--a descriptive dental laboratory study

AIM

To explore whether tooth replacement in a southern region of Vietnam is in line with the primary health care approach, aiming at health services for all people at affordable costs.

METHODS

Tooth replacement was investigated by means of prostheses as delivered by four dental laboratories of which the output was considered representative. Information was based on dental casts related to the prostheses.

RESULTS

Prostheses replaced almost all missing teeth, irrespective of the types (interrupted or shortened dental arches) and numbers of missing teeth in the dental arch they were made for. Acrylic removable partial dentures were the most common prostheses delivered (65% of removable partial dentures).

CONCLUSION

It cannot be stated that dental arch conditions in this study were representative for the southern Vietnamese population. However, it is concluded that dental practitioners tend to provide complete dental arches by tooth replacements. This morphologically based approach might introduce over treatment. In line with primary oral health care, a functionally oriented treatment management, including the shortened dental arch concept, should be implemented.

Changes in patient and FDP profiles following the introduction of osseointegrated implant dentistry in a prosthodontic practice

PURPOSE

This paper describes the effects of implant-related dentistry on patient profiles and the types of fixed dental prostheses provided in clinical practice.

MATERIALS AND METHODS

All implant- and tooth-supported prostheses provided in a prosthodontic practice between 1984 and 2007 were tabulated. Incidence was analyzed in relation to gender, age at time of prostheses insertion, and prostheses type.

RESULTS

Tooth-supported single crowns (TSCs) and tooth-supported fixed dental prostheses (TFDPs) were involved in 97% of treatments requiring fixed dental prostheses from 1984 to 1991. From 1991 to 2007, however, a marked increase in the number of implants restored directly corresponded with a decrease in the number of TFDPs so that by 2007, implant-supported fixed dental prostheses (IFDPs) accounted for 81% of all tooth replacements. Between 1984 and 2007 the incidence of TFDPs was 61% in females and 39% in males, whereas the incidence of IFDPs was 55% in females and 45% in males. IFDPs were also involved in 35% of restorations in patients under 31 years of age and TFDPs in 19%. In the under-21 years age group, IFDPs were more common in females (9%) than males (4%), but in the 21 to 30 years age group they were more common in males (21%) than females (13%). There was a decrease in three-unit TFDPs, in TFDPs with four or more pontics and those not satisfying Ante's Law, and in teeth used that had been subjectively assessed to have an unfavorable 10-year prognosis at the time of prosthesis insertion.

CONCLUSIONS

The incorporation of osseointegrated implant dentistry into a clinical practice has resulted in changes in the patient profile and type of fixed dental prostheses provided, including a decrease in the use of TFDPs; an increase in the referral of patients under 31 years of age; a decrease in three-unit, long-span, and complex TFDPs; and a decrease in tooth abutments assessed to be structurally or biologically compromised.

[Some characteristics of distal cantilever bridges on the basis of two representative studies (in Hungary)]

In Hungary a dental epidemiological study was performed by a team of calibrated dentists of the Department of Prosthetic Dentistry (Semmelweis University, Budapest) in 1985-89 for the first and in 2003-2004 for the second time. Probands were selected randomly from the population attending the compulsory lung screening examinations. Oral inspection was done under artificial light. Data were immediately entered into computer on the spot. In the first epidemiological study after the examination of 9991 people we have found 1625 cantilever bridges, in the second study we examined 4606 people, and we have found 878 cantilever bridges. In 1989 66.9% of the cantilever bridges replaced missing tooth on the mesial and 33.1% on the distal end. In 2004 44.5% of the cantilever bridges replaced missing tooth on the mesial and 55.5% on the distal end. In both investigations one pontic distal cantilevers were the majority of restorations. In the study of 1989 we have found the highest number of the bridges with one distal pontic supported by two abutments. In the 2004 study the most frequently found one pontic distal cantilever bridges were supported by more then two abutments. Both investigations found the most distal cantilever bridges in the upper jaw replacing the first molar (32%, 38%), then the second molar (20%, 28%), and first premolar (18%, 20%). On the lower jaw distal cantilever pontics were replacing first molars in most of the cases (61%, 59%), then second premolars (19%, 24%) and first premolars (8%, 9%). In both investigations most frequently free end saddle (74%, 83%), remaining teeth (19%, 16%), crowns and artificial teeth distally from the cantilever pontic have been found.

[Monitoring trends in fixed partial denture design based on national surveys]

To restore partially edentulous arches reasonable number of fixed partial dentures (FPD) are used in Hungary. This paper describes statistic parameters of these restorations based on analysis of a large sample size. Dentists of the Department of Prosthodontics performed oral health surveys according to WHO criteria, first survey in 1985-1989 and second in 2003-2004. The oral surveys were carried out at the lung cancer screening stations among those individuals originally referred to undergo x-ray lung screening examination. In the "first" survey data collected on 6224 FPD; in the "second" survey data collected on 3676 fixed restorations were analyzed. Besides time parameters, number of pontic teeth, abutment teeth to pontic teeth ratio (abutment saturation), position of pontic teeth in the arch, position of abutment teeth in the arch, main features of "tooth location" adjacent to restoration (remnant tooth, crown, artificial tooth, missing tooth), framework- and veneering materials were investigated. For interpreting data SPSS 10.0.5 for Windows was applied. Restorations' mean survival time was 9.34 +/- 8.47 years. Average number of FPD unit was: 6.34 for the maxillary and 4.62 for the mandibular jaw. Average number of abutment teeth was 3.58 in the upper and 2.82 in the lower jaw. Most frequent abutment teeth of both the maxillary and mandibular jaw were canines (23%) (20%). In order of frequency: pontics of the upper jaw replaced first premolars (27%) and second premolars (23%); lower jaw pontics replaced first molars (36%) and second premolars (21%). Findings of our survey demonstrated that results were much jaw dependent, while participants' sex and age influenced the outcome less. Comparison between left and right side of the arch revealed considerable symmetry. Recently collected data of 2004 have shown increased extension of fixed partial dentures with significantly higher number of abutment teeth involved. Statistical analysis of data collected on fixed partial dentures provide a sound basis for estimating the present oral health status of the population. Monitoring patterns of change have an important epidemiological relevance. Results of our present findings serve as a reliable source to plan future strategy of the dental care system and also helps to measure efficiency of the dental education system.

Dental state, prosthodontic treatment and chewing ability ? a study of five cohorts of 70-year-old subjects

The aim was to study the relationship between dental state, prosthetic rehabilitation and chewing ability in 70-year-old subjects examined between 1971 and 2001. Five birth cohorts born in 1901/1902 (I), 1906/1907 (II), 1911/1912(III), 1922 (V), and 1930 (VI) were examined at 70 years of age. The number of participants in the odontological cohorts varied between 386 and 583. The prevalence of total edentulism changed from 51% in cohort I to 7% in cohort VI. The proportion of subjects using removable dentures decreased from 76% to 17%, whereas those with >or=20 teeth increased from 13% to 65%. The prevalence of subjects with fixed partial dentures increased from 26% to 58%. Of the 70-year-old subjects examined in 2001, 5% had implant-supported restorations. The self-assessed chewing ability showed only weak associations with dental state, and there was no significant cohort trend. When all cohorts were pooled together, 80% considered their chewing ability good, 16% less good and 4% poor. Among the edentulous subjects, more individuals complained about poor chewing ability in the last two cohorts than in the first three. It was concluded that there were great differences in dental state between the five cohorts of 70-year-old subjects examined from 1971 to 2001. Edentulism and wearing of removable dentures decreased substantially, whereas the proportion of subjects with fixed partial dentures showed a marked increase. In spite of the improved dental state, the self-assessed chewing ability exhibited only minor variation over time.

The oral hygiene and denture status among residential home residents

The aim of this study was to investigate the oral hygiene practices and denture status of elderly people living in a residential home. One hundred one elderly people living in Gurcesme Zubeyde Hanim Residential Home, Izmir-52 women (mean age 75.5 +/- 7.8) and 49 men (mean age 75.3 +/- 8.8)-participated in an interview. Their oral hygiene practices, self-perceived oral health, denture status, and needs of denture were noted down. Self-perceived oral health was very bad in 9.9%, bad in 47.5%, good in 33.7%, and very good in 8.9%. From 69 people who reported maintaining oral hygiene, the incidence of oral hygiene practice was 36.2% once a day, 31.9% three times a day, 21.8% once a week, and 10.1% seldom. The majority, 60 people (59.4%), were dentate. Among the dentate, 47 people (78.3%) had full denture, 4 (6.6%) removable partial denture, 2 (3.3%) fixed/removable partial denture, 5 (8.3%) full/removable partial denture, and 2 (3.3%) one or more fixed partial dentures. By gender, 57.6% female and 61.2% male subjects were dentate. The relationship between having a social security and having a denture was significant (p = 0.02); having a denture and needing a denture was also significantly related (p = 0.00). The high prevalence of needs for denture pointed to the requirement for frequent dental check ups. The most important need within the residents of the residential home was daily oral hygiene. Nurses trained on this subject are required.

A 5-year retrospective study of fixed partial dentures: success, survival, and incidence of biological and technical complications

The aim of this retrospective study was to determine the probability of success and survival as well as the incidences of specific biological and technical complications associated with fixed partial dentures (FPDs). All patients fitted with FPDs at the National Dental Center, Singapore, in the previous 5-8 years were identified through electronic records and contacted to return for a clinical examination by a prosthodontist. Eighty-five patients with a total of 99 FPDs were examined, and a satisfaction survey was also conducted. Fifty-eight (58.6%) of the FPDs were successes requiring no intervention. Thirty-two (32.3%) remained in situ but suffered some complications, while nine (9.1%) were deemed failures as they had to be removed. Of the 32 complications, one (1%) showed increased mobility due to progressive periodontitis, four (4%) had lost vitality, two (2%) required recementation, two (2%) showed recurrent caries, and 23 (23.2%) exhibited partial ceramic fractures. The 5-year probability of success was between 62.5% (95% confidence interval [CI]: 52.7, 71.2) and 68% (95% CI: 59.5, 76.0), while the 5-year probability of survival was 92.3% (95% CI: 86.5, 96.6). The incidence of caries was 5.8% (95% CI: 2.5, 11.8), and the 5-year risk for loss of abutment vitality was 4.4% (95% CI: 1.5, 9.5). FPDs with non-vital abutments and those of a longer span (5 or more units) were more likely to suffer a complication or failure.

Dental technicians' experiences with all-ceramic extra-coronal restorations

The aim of this study was to identify the dental technicians' experiences with extra-coronal all-ceramic restorations. A questionnaire was mailed to all laboratories registered in The Norwegian Association of Dental Laboratory Owners (n=186). The response was 149 (80%). All-ceramic restorations were produced by 93 (62%) of the responding laboratories. A few of these (1 7%) produced the majority (67%) of the restorations. The dental technicians reported low rates of remakes (median 2%) for all-ceramic restorations. The low production and the limited number of laboratories that perform this work show that there is room for extended training and more expertise in this field.

A five-year life-table analysis on wide neck ITI implants with prosthetic evaluation and radiographic analysis: results from a private practice

This paper reports a 5-year life-table analysis on wide neck (WN) ITI implants placed in a private practice. In 212 patients, 263 implants were placed in the posterior region; 97% rehabilitated the molar area. Implants in the mandible and in the maxilla were 61.2% and 38.8%, respectively; the mean implant length was 9.7 and 8.9 mm, respectively. Eighty-nine percent sites had both vestibular and buccal bone lamellae > or =1 mm, 9.1% had one of them <1 mm and 1.9% had both lamellae <1 mm. Sinus perforation during surgery occurred in 52% of the maxillary implants. Prosthetic information was available for 249 implants; implants were involved in 157 single crowns (SC) and 80 fixed partial dentures (FPD). Radiographic analysis was performed on 102 implants that reached the 2-year control, and crestal bone loss (CBL) was measured. Results showed that five implants failed; the 5-year cumulative survival rate was 97.89%. The 1-year survival rate based on 259 implants was 98.8% and the 2-year survival rate based on 174 implants was 97.7%. In this 5-year timeframe, 94.3% of the SCs and 96.2% of the FPDs were free of complication. The mean CBL at the mesial and distal sides was 0.71 and 0.60 mm, respectively; bone losses >1 and >2 mm were recorded for 29.7% and 2.5% of the sides, respectively. This mid-term study showed that the WN ITI implants were highly predictable in private practice and that prosthetic complication in the molar area was an infrequent event.

Survival Rate of Endodontically Treated Teeth With Posts After Prosthetic Restoration

The purpose of this retrospective clinical study was to evaluate the survival rate of teeth that were endodontically treated and restored with endodontic posts and prosthodontic restorations. A total of 864 teeth in 360 patients were included in the study. Dental records and radiographs of the patients were evaluated and four parameters were documented. The parameters were type of post, type of prosthodontic restoration, observation time, and, in cases of failure, failure mode. Statistical survival analyses were performed according to Kaplan-Meier. The mean observation time was 22.5 +/- 14.9 months. The calculated survival rates of the abutments were statistically significant different for fixed partial dentures (FPDs) and for removable partial dentures (RPDs) with survival rates of 92.7% and 51.0% after 60 months, respectively. Most of the presumed factors influencing the survival rate of endodontically treated abutment teeth only affected the outcome in the RPD group. Teeth restored with post and cores present a high risk for failure when used as abutments for conical-double-crown-retained RPDs.

Fixed partial prostheses supported by 2 or 3 implants: a retrospective study up to 18 years

PURPOSE

The purpose of this study was to evaluate and compare the long-term performance of fixed partial prostheses supported by 2 or 3 implants.

MATERIALS AND METHODS

All patients treated with fixed partial prostheses supported by either 2 or 3 implants during the period 1985 to 1998 were included in this retrospective report. Annual clinical follow-up examinations were performed, with special attention to stability of the prostheses and peri-implant and occlusal conditions. Radiographic examination was performed when the prostheses were delivered (year 0) and subsequently at 1-year, 5-year, and 10-year examinations.

RESULTS

A total of 178 patients had received fixed partial prostheses (FPPs) during this period of whom 123 (77 women and 46 men) were available for follow-up (mean age = 65 years, range 32-91). These 123 patients received a total of 146 implant-supported FPPs (63 two-implant- and 83 three-implant-supported) supported by 375 implants. The mean observation periods for the 2- and 3-implant-supported restorations were 9.6 years and 9.4 years (range, 5 to 18 years), respectively. Survival rates for the 2- and 3-implant-supported prostheses were 96.8% and 97.6%, respectively. The implant survival rate after loading was 98.4% for both groups. The mean bone loss at the 5-year follow-up was 0.3 mm for the 2 groups. No significant differences in bone loss (P > .05), implant failure rate (P > .05), or incidence of mechanical complications (P > .05) were found between the 2 prosthesis designs. The complications differed, significantly, with more loose gold and abutment screws in the 2-implant-supported group (P < .05) and more porcelain fractures in the 3-implant-supported group (P < .05).

CONCLUSION

The 2-implant-supported partial prostheses exhibited long-term clinical performance comparable to prostheses supported by 3 implants.

Prevalence of subjects with progressive bone loss at implants

AIM

The aim of the present study was to assess the prevalence of subjects with progressive bone loss at implants with a function time of at least 5 years.

MATERIAL AND METHODS

Radiographs of 1346 patients who had attended annual follow-up visits at the Brånemark Clinic, Public Dental Services, Gothenburg, Sweden were retrieved. Six hundred and sixty-two subjects fulfilled the inclusion criteria. Thus, they all had been provided with implant-supported (Brånemark System) Nobel BioCare, Gothenburg, Sweden) fixed partial or complete dentures or single-tooth replacements with a documented function time in radiographs of at least 5 years. Implants that demonstrated progressive bone loss to a level of > or =3 threads of an implant were detected. The number of subjects who exhibited one or more implants with progressive bone loss to the threshold level was recorded.

RESULTS

Twenty-eight percent of 662 included subjects had one or more implants with progressive bone loss. A logistic regression analysis revealed that the individuals in this group carried a significantly larger number of implants than the subjects in whom no implants with progressive loss were detected (6 vs. 4.8). Furthermore, >30% of the subjects in the group with progressive bone loss had > or =3 identified implants and that about 33% of all such implants in this group exhibited extensive bone loss. Out of the total 3413 implants included in the study, 423 implants (12.4%) demonstrated progressive bone loss.

CONCLUSION

It is suggested that the prevalence of progressive bone loss at implants assessed from subject-based data is higher than that evaluated from implant-based data.

Factors Associated with Implant Recommendation for Single-Tooth Replacement

The use of dental implants for single-tooth replacement has been established as a predictable treatment option; yet, limited data are available as to how frequently this option is recommended to patients. The aim of the present study was to examine the frequency of implant recommendation by general dental practitioners after single-tooth extraction and factors influencing their decision to recommend an implant. All single-tooth extractions performed in 26 general dental practice clinics in Kuwait over a 30-day period were examined. Dentists in these centers used the study form to record demographic data, the type of tooth extracted, reason for extraction, and replacement options presented to the patients. Univariate and logistic regression analyses were used to examine associations between background factors and decisions to recommend implant therapy. A total of 1367 patients (mean age, 37.9 +/- 11.8 years) had an extraction of one tooth during the study period. Forty-three patients were offered implants as a replacement option (3.3% of the total sample; 8.6% of patients who were offered tooth replacement options). Factors associated significantly with the recommendation of an implant by Kuwaiti dentists to their patients included younger age, regular dental maintenance visits, and adequate oral hygiene practices (P < 0.05; binary logistic regression). Dental implant recommendation for single-tooth replacement in the present sample of dentists was low. Factors associated significantly with dentist recommendation of an implant for single-tooth replacement included age, history of dental maintenance, and oral hygiene practices.

A systematic review of the survival and complication rates of fixed partial dentures (FPDs) after an observation period of at least 5 years. IV. Cantilever or extension FPDs

OBJECTIVES

The objective of this systematic review was to assess the survival of cantilever fixed partial dentures (FPDs) and the incidence of biological and technical complications.

METHODS

An electronic MEDLINE search supplemented by manual searching was conducted to identify prospective and retrospective cohort studies on FPDs with a mean follow-up time of at least 5 years. Patients had to have been examined clinically at the follow-up visit. Assessment of the identified studies and data abstraction was performed independently by two reviewers. Failure and complication rates were analyzed using random-effects Poisson regression to obtain summary estimates of 10-year survival proportions.

RESULTS

From a yield of 3658 titles and 211 abstracts, 81 articles were selected for full-text analysis, finally resulting in 13 studies that met the inclusion criteria. Meta-analysis of these studies resulted in an estimated survival rate of cantilever FPDs of 81.8% (95 percent confidence interval (95% CI): 78.2-84.9%) and success rate (free of all complications) of 63% (95% CI: 54.7-70.2%) after 10 years. The most common biological complication was loss of pulp vitality (32.6%) followed by caries at abutment teeth (9.1%). After a 10-year observation period 2.6% of the FPDs were lost as a result of dental caries and 1% due to recurrent periodontitis. The most frequent technical complication was loss of retention (16.1%) followed by material fractures (5.9%). The cumulative incidence of fractures of abutment teeth was 2.9% and 2.4% of the FPDs were lost as a result of abutment tooth fracture after an observation period of 10 years.

CONCLUSION

This systematic review on cantilever fixed partial dentures indicated that survival and success rates of cantilever fixed partial dentures were lower than those of conventional end-abutment supported FPDs described in a review by Tan et al. (2004) and biological and technical complications were frequent.

A systematic review of the survival and complication rates of fixed partial dentures (FPDs) after an observation period of at least 5 years. III. Conventional FPDs

The present study was done to determine the long-term success and survival of fixed partial dentures (FPDs) and to evaluate the risks for failures due to specific biological and technical complications. A MEDLINE search (PubMed) from 1966 up to March 2004 was conducted, as well as hand searching of bibliographies from relevant articles. Nineteen studies from an initial yield of 3658 titles were finally selected and data were extracted independently by three reviewers. Prospective and retrospective cohort studies with a mean follow-up time of at least 5 years in which patients had been examined clinically at the follow-up visits were included in the meta-analysis. Publications only based on patients records, questionnaires or interviews were excluded. Survival of the FPDs was analyzed according to in situ and intact failure risks. Specific biological and technical complications such as caries, loss of vitality and periodontal disease recurrence as well as loss of retention, loss of vitality, tooth and material fractures were also analyzed. The 10-year probability of survival for fixed partial dentures was 89.1% (95% confidence interval (CI): 81-93.8%) while the probability of success was 71.1% (95% CI: 47.7-85.2%). The 10-year risk for caries and periodontitis leading to FPD loss was 2.6% and 0.7%, respectively. The 10-year risk for loss of retention was 6.4%, for abutment fracture 2.1% and for material fractures 3.2%.

A systematic review of the survival and complication rates of fixed partial dentures (FPDs) after an observation period of at least 5 years. II. Combined tooth-implant-supported FPDs

OBJECTIVES

The objective of this systematic review was to assess the 5- and 10-year survival of combined tooth-implant-supported fixed partial dentures (FPDs) and the incidence of biological and technical complications.

METHODS

An electronic MEDLINE search supplemented by manual searching was conducted to identify prospective and retrospective cohort studies on FPDs with a mean follow-up time of at least 5 years. Patients had to have been examined clinically at the follow-up visit. Assessment of the identified studies and data abstraction was performed independently by two reviewers. Failure and complication rates were analyzed using random-effects Poisson regression models to obtain summary estimates of 5- and 10-year survival proportions.

RESULTS

From a total of 3844 titles and 560 abstracts, 176 articles were selected for full-text analysis, and 13 studies met the inclusion criteria. Meta-analysis of these studies indicated an estimated survival of implants in combined tooth-implant-supported FPDs of 90.1% (95 percent confidence interval (95% CI): 82.4-94.5%) after 5 and 82.1% (95% CI: 55.8-93.6%) after 10 years. The survival rate of FPDs was 94.1% (95% CI: 90.2-96.5%) after 5 and 77.8% (95% CI: 66.4-85.7%) after 10 years of function. There was no significant difference in survival of tooth and implant abutments in combined tooth-implant FPDs. After an observation period of 5 years, 3.2% (95% CI: 1.5-7.2%) of the abutment teeth and 3.4% (95% CI: 2.2-5.3%) of the functionally loaded implants were lost. After 10 years, the corresponding proportions were 10.6% (95% CI: 3.5-23.1%) for the abutment teeth and 15.6% (95% CI: 6.5-29.5%) for the implants. After a 5 year observation period, intrusion was detected in 5.2% (95% CI: 2-13.3%) of the abutment teeth. Intrusion of abutment teeth were almost exclusively detected among non-rigid connections.

CONCLUSION

Survival rates of both implants and reconstructions in combined tooth-implant-supported FPDs were lower than those reported for solely implant-supported FPDs (Pjetursson et al. 2004). Hence, planning of prosthetic rehabilitation may preferentially include solely implant-supported FPDs. However, anatomical aspects, patient centered issues and risk assessments of the residual dentition may still justify combined tooth-implant-supported reconstructions. It was evident from the present search that tooth-implant-supported FPDs have not been studied to any great extent and hence, there is a definitive need for more longitudinal studies examining these reconstructions.

A systematic review of the survival and complication rates of fixed partial dentures (FPDs) after an observation period of at least 5 years. I. Implant-supported FPDs

OBJECTIVES

The objective of this systematic review was to assess the 5- and 10-year survival of implant supported fixed partial dentures (FPDs) and to describe the incidence of biological and technical complications.

METHODS

An electronic MEDLINE search complemented by manual searching was conducted to identify prospective and retrospective cohort studies on FPDs with a mean follow-up time of at least 5 years. Patients had to have been examined clinically at the follow-up visit. Assessment of the identified studies and data abstraction was performed independently by two reviewers. Failure and complication rates were analyzed using random-effects Poisson regression models to obtain summary estimates of 5- and 10-year survival proportions.

RESULTS

The search provided 3844 titles and 560 abstracts. Full-text analysis was performed for 176 articles resulting in 21 studies that met the inclusion criteria. Meta-analysis of these studies indicated an estimated survival of implants in implant-supported FPDs of 95.4% (95 percent confidence interval (95% CI): 93.9-96.5%) after 5 and 92.8% (95% CI: 90-94.8%) after 10 years. The survival rate of FPDs supported by implants was 95% (95% CI: 92.2-96.8%) after 5 and 86.7% (95% CI: 82.8-89.8%) after 10 years of function. Only 61.3% (95% CI: 55.3-66.8%) of the patients were free of any complications after 5 years. Peri-implantitis and soft tissue complications occurred in 8.6% (95% CI: 5.1-14.1%) of FPDs after 5 years. Technical complications included implant fractures, connection-related and suprastructure-related complications. The cumulative incidence of implant fractures after 5 years was 0.4% (95% CI: 0.1-1.2%). After 5 years, the cumulative incidence of connection-related complications (screw loosening or fracture) was 7.3% and 14% for suprastructure-related complications (veneer and framework fracture).

CONCLUSION

Despite a high survival of FPDs, biological and technical complications are frequent. This, in turn, means that substantial amounts of chair time have to be accepted by the clinician following the incorporation of implant-supported FPDs. More studies with follow-up times of 10 and more years are needed as only few studies have described the long-term outcomes.

[The survey of prosthetic treatment in the elderly]

OBJECTIVE

To acquire teeth and prosthetic conditions of the elderly.

METHODS

1166 patients of over 60 years old had been given prosthetic treatment, and the teeth conditions were analyzed.

RESULTS

The average number of missing teeth was 10.25. The maxillary missing teeth were more than mandibular ones. The rate of missing teeth were as follows: maxillary teeth > mandibular teeth; molars > bicuspids > incisors > cuspid. 1120 cases were treated with removable dentures. 59% of the removable partial dentures had free-end saddles. 46 cases were treated with fixed bridges.

CONCLUSION

The characteristics of prosthetic patients in the elderly were as follows: a large number of missing teeth and free-end missing teeth, attrition of resident teeth, food impaction, existing-residual root and loosen teeth. Removable denture was the main method of the prosthetic therapy for the elderly patients. Fixed bridge was used when the patient condition was good. The cuspid, treated residual root and the third molar should be used for the retention and support of the prosthesis.

Fixed partial denture or single-tooth implant restoration? Statistical considerations for sequencing and treatment

The choice to replace a single missing tooth can be based on the primary decision that the restorability of the tooth is in doubt. Many teeth are decimated by incipient or recurrent caries, trauma, endodontic complications, or periodontal disease which requires extraction. It is our objective to familiarize the participant with literature comparing success rates of fixed partial dentures and single-tooth implant restorations and a repertoire of prosthodontic techniques used in replacement of single missing teeth with osseointegrated dental implants. The fixed partial denture (FPD) has been regarded as the standard of care for some time in replacement of single and multiple missing teeth. Many studies surveying long term survival have been compiled and analyzed to arrive at a generalized outcome. Most of these studies arrive at common conclusions. Studies surveying success of single-tooth implant-supported restorations are not comparably abundant nor survey for comparable time as those for FPDs. Although, many of the outcomes are statistical survival estimates such as Kaplan-Meier survival tables, implant restorations in partially dentate patients are a predictable means of tooth replacement. There are certain factors which make FPD more appropriate and conversely factors which make an implant restoration more appropriate. Indications and contraindications for each treatment scenario will also be reviewed based on the literature and clinical experience. It is hoped that the practitioner will be able to appropriately identify those cases in which either an FPD or an implant restoration is the appropriate treatment option.

[Statistical analysis of the fabrication of fixed and removable partial dentures (in 2002)]

A statistical survey based on laboratory records was performed on the number of fixed partial dentures and removable partial dentures fabricated at the dental hospital of Tokyo Medical and Dental University from April 1 to September 30, 2002. A comparison was also performed with a previous survey that had been carried out in 1997 to detect any change and possible alternations in the near future. From the findings of this statistical survey, the conclusions were as follows: 1. A total of 2,656 fixed and removable partial dentures were fabricated during the six-month period in 2002. 2. The 3-unit fixed partial denture was most common (64.0%), and the number of fixed partial dentures decreased as the number of units increased. 3. For a single missing tooth, a fixed partial denture was more popular (80.8%) than a removable partial denture. 4. For two missing teeth, there was little difference between the number of fixed and removable partial dentures. In the anterior region, fixed partial denture was more common, while in contrast, in the posterior region, removable partial denture was more common.

A 5-year follow-up study on the prosthetic rehabilitation of the elderly in Helsinki, Finland

In 1990, 364 elderly (76-86 years) inhabitants of Helsinki, Finland, attended a dental and oral examination study that was conducted as part of the Helsinki Aging Study. In spring 1996, these subjects were recalled for a 5-year follow-up. Between the baseline and follow-up examinations, 114 (31%) subjects had deceased (86 women and 28 men), whereas 134 had either moved, were too ill, or refused to participate in the follow-up. Follow-up examination was conducted for 113 subjects (79 women and 34 men), with the participating rate being 46%. Five subjects became edentulous during the follow-up. Of the subjects, 61% had 1-32 teeth at follow-up. In these subjects, the mean number of teeth decreased from 14.9 (+/-8.3) to 13.5 (+/-8.6) (P < 0.0001). Prosthetic status changed in 40% of the elderly dentate people: 25% received new prostheses whereas 15% lost prostheses that were not replaced. New fixed partial dentures were made in five maxillae and in nine mandibles during the follow-up. Acrylic removable partial dentures (ARPD) were most frequently used: 35% of dentate subjects had an ARPD. Subjects with removable prostheses had higher levels of salivary microbes and higher root caries incidence than those with natural teeth. Furthermore, the presence of removable prostheses at baseline, together with the male gender, was clearly associated with tooth loss during follow-up. This study indicates that fixed rather than removable prostheses should be used in elderly patients. The need for a removable denture ought to be carefully considered.

Alginate impressions for fixed prosthodontics. A 20 year follow up study

The aim of this study was to estimate whether the survival ratios after 20 years of fixed prosthodontics made of alginate impressions was higher, equivalent or lower, compared to the survival ratios, shown in studies, where different impression materials were used. 151 females and 104 males were screened regarding the condition and age of the restorations at the annual check-up in one of the author's surgeries. Average ages were 55 and 54 years respectively, when the fixed prosthodontics were seated. A total of 1.271 units were produced during the twenty years, 911 abutment teeth and 360 pontics. The type of prosthetic work was divided into three groups: 1) larger fixed prosthodontics 6-14 units (469), 2) smaller fixed prosthodontics 2-5 units (541) and 3) single crowns (261). The results show that alginate impressions can produce fixed prosthodontics with survival ratios similar to those presented in other studies, after 5 years (99%), 1o years (93-96%) and 15 years (74-96%). After 20 years the survival ratio was 61-63%. In conclusion, fixed prosthodontics made according to the syringe-tray alginate impression method may have the same success rates after 20 years compared to that of fixed prosthodontics presented in previous longitudinal clinical studies where other impression materials had been used. In this study, caries and root fractures were the main reasons for removing abutment teeth and pontics.

Use of mandibular implant overdentures: treatment policy in prosthodontic specialist clinics in Sweden

The aim was to examine the use of mandibular implant overdentures in Swedish prosthodontic specialist clinics. Questionnaires related to treatment with mandibular implant overdentures during 2001 were sent to the heads of the 30 prosthodontic specialist clinics of the Public Dental Health Service in Sweden. Completed questionnaires were received from 28 (93%). The number of treatments with mandibular implant overdentures varied much among the clinics (0 to 22). Seven clinics had not performed any such treatment, and the median number was 2. The number of fixed implant-supported prostheses was much higher (median value 17, range 4 to 100). The correlation between the number of implant overdentures and fixed implant-supported prostheses in edentulous mandibles was weak (r = 0.33; P = 0.10). The most common anchorage system was ball attachments on two unsplinted implants. The most common reason for the choice of the overdenture treatment was the reduced cost, whereas the patient's main wish to improve denture retention came next. The question whether the demand for implant overdentures had increased during the last few years, was answered with "no" by 19, with "yes" by 5 and with "don't know" by 4 clinics. All but one responded that their attitude to implant overdentures had not changed after the introduction of free pricing in Swedish dentistry. It can be concluded that compared to the rapidly increasing international use of mandibular implant overdentures, this treatment of edentulous patients is rare in Sweden, where fixed implant-supported prostheses still are predominant.

Prosthodontic status among old adults in Pomerania, related to income, education level, and general health (results of the Study of Health in Pomerania, SHIP)

PURPOSE

The aim of the study was to evaluate associations among prosthetic status, socioeconomic factors, and general health of subjects aged 55 to 79 years. The data were taken from the Study of Health in Pomerania (SHIP).

MATERIALS AND METHODS

Socioeconomic information (age, sex, education level), medical information (number of diseases), and details on smoking and alcohol consumption were obtained. Prosthetic status in the maxilla and mandible was classified into complete denture (CD), removable partial denture (RPD), > or = 10 natural teeth or teeth replaced with fixed prosthodontics (10T+), and < or = nine natural teeth including fixed prosthodontics (9T-).

RESULTS

The data of 1,877 subjects were evaluated. CDs in the maxilla were more frequent than in the mandible. RPDs were more frequent in the mandible and in the group aged 65 to 74 years. Of the individuals with a low education level, 47% had a CD in the maxilla, and only 21% had 10T+. However, of subjects with a high education level, 22% had a CD in the maxilla, and 54% had 10T+. The odds ratio of having a CD in the maxilla increased to 11.9 at the age of 75 to 79 years, compared to 0.6 at the age of 55 to 59 years. Logistic regression analyses showed that the risk of wearing a CD was significantly associated with old age, low education level, low income, smoking, and alcohol abuse, whereas the number of diseases (used as an indicator of general health) was not.

CONCLUSION

Alcohol abuse, smoking, low education level, low income, and old age were significant predictors of wearing CDs.

Subjective need for implant treatment among middle-aged people in Sweden and Denmark

BACKGROUND

The use of oral implants in prosthodontics has become widespread and regarded as a predictable treatment modality. However, there is a lack of knowledge among the general population about the prevalence and need for implant treatments.

PURPOSE

This study was undertaken to register and compare the prevalence of dental implants and the subjective need for implant treatment among people in Sweden and Denmark.

MATERIALS AND METHODS

Random samples taken from the national population registers in Sweden and Denmark comprised 1001 Swedish subjects aged 55 to 79 years and 1175 Danish subjects aged 45 to 69 years. Subjects were requested to fill out questionnaires regarding dental conditions, subjective need for implant treatment, whether they had received treatment with dental implants during the previous 10 years, and so on.

RESULTS

Of the Swedes, 4.8% reported that they had dental implants, compared with 2.5% of the Danes. In the Swedish sample, age was significantly associated with subjective need for implant treatment. In the Danish sample, women showed a significantly higher subjective need for implant treatment than did men.

CONCLUSIONS

Compared with the Swedish sample, the subjective need for treatment with dental implants was higher in the Danish sample, although the patient fees were substantially higher in Denmark.

Prosthetic treatment need in a representative German sample

Regarding declining resources epidemiological data on needs for oral rehabilitation are required. Within the framework of an oral health survey a non-stratified two-stage random sample was taken to represent the over 14-year-old population of Saxony/Germany. The participation rate was 55%. Normative need was determined by dental assessment and guidelines developed in a consensus process, subjective prosthetic treatment need by self-complete questionnaire. About 97% of the realized sample could be planned within the guidelines. About 81% had normative prosthetic treatment need. Compared with the rate of normative need the rate of subjective need (13%) was considerably lower (chi(2) P < 0;01). Different predictive parameters of subjective need were identified by logistic regression. Besides other factors subjective need was associated with giving dentist's recommendation as significant reason for prosthetic restorations [odds ratio (OR)=5;43], not believing that the own teeth were all right (OR=0;17), and the existence of prosthetic restorations (OR=3;87 for fixed restorations; OR=4;05 for removable dentures). The guidelines proved their suitability to assess normative prosthetic treatment need in oral health surveys. Further research is necessary to find adequate options for including patients' preferences in an adequate need definition.

Fixed prosthodontics in adults in Jönköping, Sweden in 1983 and 1993. An epidemiological study of prevalence and choice of material

The aim of the study was to assess the prevalence of fixed prostheses, i.e. single crowns and fixed partial dentures, in adults 20-80 years old in two cross-sectional studies carried out in 1983 and 1993 and to analyse whether the choice of material for fixed prostheses had changed during this time period. The material comprised 586 and 593 individuals. A descriptive analysis of number of individuals with fixed prostheses was made concerning the number of crowns and pontics, the distribution in the jaws, and the materials used. The prevalence of individuals with fixed prostheses was shown to increase with age both in 1983 and 1993. In 1993 the number of individuals with fixed prostheses was slightly lower than in 1983 (44 and 48 percent respectively). There was no difference according to gender. The proportion of individuals with fixed prostheses was lower or almost unchanged in the 20-, 30-, 40-, 50-, 60-, and 80-year-olds in 1993 compared to 1983. In the 70-year-olds, however, the proportion of individuals with fixed prostheses was considerably higher in 1993 compared to 1983. Most individuals with fixed prostheses had a small number of crowned teeth, and about half of the individuals had not more than four crowned teeth. Likewise most individuals with pontics had a small number of pontics. The distributions of crowned teeth and pontics in the jaws were similar in 1983 and 1993. Pontics and crowns were more frequent in the upper than in the lower jaw. Crowns made of porcelain or metal ceramic had increased by 1993 in the 30-80 year age groups, and the study thus confirms general clinical experience that porcelain and metal ceramic are more often the materials of choice in fixed prosthodontics in adults today.

Influence of dental care systems on dental status. A comparison between two countries with different systems but similar living standards

OBJECTIVE

To evaluate the influence of two different dental care systems on dental status, taking into account relevant socio-economic factors.

BASIC RESEARCH DESIGN

Questionnaire studies on randomly sampled subjects in Denmark and Sweden using questionnaire forms as identical as possible with regard to the different languages.

SETTING

The studies were performed late in 1998 in both countries.

PARTICIPANTS

Questionnaires were sent to 1,175 subjects aged 45-69 years in Denmark (response rate 73%) and to 1,001 subjects aged 55-79 years in Sweden (response rate 67%).

MAIN OUTCOME MEASURES

Questions about dental status and about socioeconomic factors and attitudes toward dental care were included. In logistic regression models, various dichotomies of dental conditions were used as dependent variables. State (Denmark vs. Sweden) was used as an independent variable together with socioeconomic factors and attitudes.

RESULTS

There were great differences between the countries in dental status. In the regression model with 'wearing removable denture(s)' as the dependent variable, state was the strongest predictor with an OR of above 4.1 for Denmark compared to Sweden. much stronger than variables such as age, income, education and residence.

CONCLUSION

The results indicate that the Swedish dental care system has been superior to the Danish one regarding dental status in middle aged and older populations in these two countries.

Prospective clinical 5-year study of ceramic-veneered titanium restorations with the Procera system

STATEMENT OF PROBLEM

The biocompatibility of titanium has been well documented, but clinical outcomes of ceramic-veneered titanium restorations were not conclusive.

PURPOSE

The study presents the results of a 5-year clinical study of individual crowns and fixed partial dentures (FPDs) veneered with a low-fusing ceramic of the Procera system.

MATERIAL AND METHODS

All patients at one clinic who required crowns or FPDs during a 2-year period were invited to participate. A total of 260 patients received 333 ceramic-veneered Procera restorations (242 single crowns and 91 FPDs). Clinical registrations were performed annually, and the restorations were evaluated according to the California Dental Association rating system. At the 5-year follow-up, 198 (76%) patients were examined. Most of the loss of patients could be explained.

RESULTS

Practically all Procera restorations were judged as satisfactory both at baseline and follow-up examinations. One artificial crown and 1 FPD were remade because of extensive fractures of ceramic veneers. Two FPDs had fractures of a soldered joint, but only 1 FPD was replaced. Some minor complications occurred, such as small porcelain fractures that could be polished (6% of single crowns, 13% of FPDs) and or loosened restorations that were recemented. Other recorded complications were not related to the Procera system but to dental caries, loosened posts and cores, and root fractures.

CONCLUSION

Clinical outcomes over a 5-year period for ceramic-veneered titanium restorations with the Procera system were favorable.

[Cantilever bridges--a cross-sectional study]

Life expectancy and functional performance of the cantilever bridges is determined by the length of the cantilever pontic(s) and by the number and localisation of the abutment teeth. No overall epidemiological survey covering this topic was found in the literature. 529 distally cantilevered bridges were evaluated by the authors. There were 310 upper and lower cases. The following parameters were recorded: length of the cantilever part (number of units), the relationship of the cantilevered pontics and the bridge, and the position of the fixed restoration in the dental arch. Previously the cantilevered bridge design was not accepted in Hungary but in spite of this fact a large number of distally cantilevered bridges were made in the country. Most of the examined cantilever bridges are properly designed: two abutments are supporting one pontic (342 cases, 65.56%). However some of the solutions are too risky: one abutment, one cantilevered pontic (110 cases, 20.45%), or two abutments, two cantilevered pontics (53 cases, 9.85%).

Implant-retained cantilever fixed prosthesis: where and when

STATEMENT OF PROBLEM

Many clinical situations are suitably treated with cantilevered implant-supported cemented fixed restorations.

PURPOSE

This article details the indications for the restorative dentist to use a cantilever fixed prosthesis after insertion of ITI dental implants.

CONCLUSION

The use of implants to support cantilevered fixed partial dentures has been successful in selected clinical situations.

Clinical performance and periodontal outcome of temporary crowns and fixed partial dentures: A randomized clinical trial

STATEMENT OF PROBLEM

Different materials (autopolymerizing, dual curing, and light initiated) are used for fabricating provisional restorations during prosthetic treatment. Randomized clinical trials that have evaluated these provisional materials have not been published.

PURPOSE

This clinical trial compared the handling, fitting, plaque adherence, gingivitis, color stability, and the subjective assessment of the provisional materials by the patient and the dentist for 2 autopolymerizing (Protemp, Luxatemp), 1 dual-curing (Provipont), and 1 light-initiated (Triad-VLC) material for the manufacturing of temporary crowns and fixed partial dentures.

MATERIAL AND METHODS

Thirty subjects in need of 2 similar fixed prosthetic restorations (single crowns ¿20, three-quarter crowns ¿2, connected crowns ¿9, or fixed partial dentures ¿30) were treated with 1 temporary restoration of Protemp II (control) and one randomly selected from Luxatemp, Provipont, or Triad-VLC materials. The mean time of treatment was 37.5 days (minimum 2 days, maximum 156 days). All restorations were manufactured intraorally with a vacuum-formed template.

RESULTS

Mechanical and retentive characteristics revealed a high level of clinical reliability. Plaque adherence of the teeth with temporary restorations was significantly increased (P =.0039) compared with the untreated mesial reference teeth.

CONCLUSION

The advantageous mechanical properties of the light-curing and dual-curing materials reviewed in dental literature were clinically offset by disadvantages in handling.

Surface quality achieved by polishing and by varnishing of temporary crown and fixed partial denture resins

STATEMENT OF PROBLEM

Studies have suggested that coating a temporary restoration with varnish material could replace time-consuming polishing procedures needed for achieving an optimally smooth surface.

PURPOSE

This study examined the surface roughness of acrylic resins after having been polished or coated with different varnish materials.

MATERIAL AND METHODS

A total of 360 cylindrical specimens were fabricated from 9 brands of resin. One surface on each specimen was machined flat and subsequently either polished with rubber polishers or coated with 1 of 9 varnishes. Selected specimens were subjected to thermal cycling (5 degrees C to 55 degrees C, 2000 cycles). Surface quality was assessed by means of a profilometer and by SEM examination.

RESULTS

Polished specimens had average surface roughness values (Ra) of 0.8 microm; differences in roughness between materials were small, but statistically significant. Type of coating had a significant influence on surface quality. Depending on the combination of materials used, the coating produced both smoother and rougher surfaces than polishing (0.4 microm < Ra < 4.6 microm). Five coatings were deemed not to be clinically applicable because of poor wetting properties. Thermal cycling did not significantly influence surface quality, but caused minute cracks in the cyanoacrylate coating.

CONCLUSION

In regard to surface quality and applicability, the use of varnishes on temporary restorations is not advisable.

[Statistical analysis of fabrication of fixed and removable partial dentures]

A statistical survey based on laboratory records was performed on the number of fixed and removable partial dentures fabricated at the dental hospital of Tokyo Medical and Dental University from April 1 to September 30, 1997. A comparison was also performed with a previous survey, which had been carried out in 1986, in order to detect any change and possible alterations in the near future. From the findings of this statistical survey, the conclusions were as follows: 1. A total of 2,478 fixed and removable partial dentures were fabricated during the six month period in 1997. 2. The 3-unit fixed partial denture (bridge) was most common (63.1%) and the number of bridges decreased as the number of units increased. 3. For the single missing tooth, a fixed bridge was more popular (81.0%) than a removable partial denture. 4. For two missing teeth, there was no difference between the number of fixed bridges and removable partial dentures. 5. The percentage of fixed and removable partial dentures, which were not covered by health insurance, decreased to a large extent in comparison with the survey in 1986.

Evaluation of wear of selected prosthetic materials in contact with enamel and dentin

STATEMENT OF PROBLEM

The proper choice of prosthetic materials for restoration of occlusal surfaces is important for the protection of the hard tissue of the opposing teeth and for regular functioning of the stomatognathic system.

PURPOSE

This study evaluated the resistance to wear of gold, Palliag M, Dentacolor, Chromasit, and Stellon materials and the enamel and dentin of natural teeth during functional contacts in an artificial oral environment with and without an abrasion material (Al2 O3 ).

MATERIAL AND METHODS

The 5 nonceramic prosthetic materials used in the restoration of occlusal surfaces of fixed partial dentures were examined in contact with enamel and dentin during a simulated masticatory process in 2 environments (with and without abrasion). Wear was evaluated by means of a special device designed for wear examination.

RESULTS

The findings highlighted that the wear of nonceramic prosthetic materials in contact with enamel or dentin was similar. Dentin showed greater wear when in contact with these materials than with the enamel surface.

CONCLUSION

Artificial environmental factors significantly influenced the wear of the hard tissue of teeth, especially when in contact with materials having low microhardness.

Congruence between self-reported and actually provided prosthodontic services among Swedish dentists

The purpose of this study, comprising two parts, was to investigate the congruence between answers given by general dentists in questionnaires concerning prosthodontic services and the recorded information on the services actually performed by each dentist. In Part I it is investigated whether questionnaire reports of weekly working hours devoted to prosthodontics can be used as indicators of actual prosthodontic production. Part II deals with the dentists' self-reported numbers of single crowns, fixed partial dentures (FPDs), and removable dentures. These reported services are compared with the services actually provided. Part I: A regression analysis indicates a lacking precision for the individual dentist, indicated by a relatively low explained variance (R2 = 0.20). However, a highly significant association is seen between the two production measures (P = 0.000). Part II: The congruence between stated and actually provided services is higher for single crowns and removable dentures than for FPDs. Bivariate regression models are statistically significant for all three services. In Part II, the reported weekly working hours used for prosthodontics covaries significantly with prosthodontic production, but the association is not as strong as in Part I. Although the precision in both Part I and Part II is low for the individual dentist, the questionnaire measure is found to be useful as an indicator in a population of dentists. It is concluded that the questionnaire data can be used as reasonably valid expressions of prosthodontic activity in population-oriented analyses among general dentists.

[Evaluation of the dental status from he viewpoint of denture requirements in the adult population of Hungary]

Authors found a rather high number of missing teeth of the Hungarian population, whereas the claim of the patients to dentures is less than the capacity of the dental professionals. The percentage of the patients wearing fixed and/or removable dentures is only around 50% (mean value), in the aesthetically not disadvantageous cases (i.e.: classes 1/a; 2/a; Fábián-Fejérdy) only 30-40%, but in the aesthetically disadvantageous cases 70-80% (i.e.: classes 1/b; 2/a/1; 3; Fábián-Fejérdy). The percentage of the men wearing dentures is higher than the percentage of the men (61.9% and 44.9% respectively). Authors concluded that, the most important expectations of the patients to dentures are aesthetic. The injurious effects of not reconstructed missing teeth have minor effects on the patients motivation.

Thermal cycling distortion of porcelain fused to metal fixed partial dentures

STATEMENT OF PROBLEM

The initial fit of porcelain fused to metal restorations deteriorates during the firing cycle of porcelain.

PURPOSE

This study evaluated thermal cycling distortion of 3-unit porcelain fused to metal frameworks at different firing stages.

MATERIAL AND METHODS

A master model was designed to represent the 2 abutments of a 3-unit fixed partial denture replacing a missing mandibular molar. Standard techniques were used to fabricate 10 castings. Half of the copings were cast in a Ni-Cr alloy and the other half in a Pd-Cu alloy. Framework distortion was measured by means of inner fit changes, horizontal linear measurements of the framework length, and vertical fit changes of each retainer. Measurements were made (1) initially, (2) after degassing firing, and (3) after glaze firing. Differences between the firing cycles created distortion values of the retainers in 3 dimensions. Repeated measures ANOVA was used to analyze data statistically.

RESULTS

Measured differences between the 2 firing stages ranged from -47 to 81.7 micrometer. For both alloy groups, retainers showed increase in vertical gap that implied poorer vertical fit after porcelain application. Mean values of inner fit change recorded for porcelain application firing were higher in magnitude than the values of metal-conditioning firing. In addition, no statistically significant differences were found among alloy types.

CONCLUSIONS

A 3-dimensional distortion was observed both in Pd-Cu and Ni-Cr frameworks during porcelain firing cycle. The distortion seen after porcelain application firing was significantly greater than that seen after metal-conditioning firing. This result can be attributed to these factors, contamination of porcelain to the inner surface of metal coping and reduction in resilience of metal.