Tokyo Dental College Chiba Hospital Research Articles

Clinical evaluation of periodontal pathogen levels by real-time polymerase chain reaction in peri-implantitis patients

ObjectiveThe mechanisms underlying the onset and progression of peri-implantitis are similar to those of periodontitis, and the causative bacteria are believed to similar. Previous studies support an association between peri-implantitis and periodontal pathogen. Thus, we investigated the bacterial flora of peri-implantitis patients in comparison to those of healthy implant and periodontitis patients.Materials and methodsIn total, 70 patients visiting Tokyo Dental College Chiba Hospital were divided into four groups: healthy, periodontitis, healthy implant, and peri-implantitis. For each group, the following five periodontal pathogens were detected using real-time polymerase chain reaction: Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, Tannerella forsythia, Treponema denticola, and Prevotella intermedia.ResultsThe average copy number of total bacteria was significantly higher in the periodontitis group than in the other groups. P. gingivalis was detected in the periodontitis and peri-implantitis groups at levels as high as 18.92% and 12.29%, respectively, and P. intermedia was found in the peri-implantitis group at a rate of 2.06%. Nevertheless, periodontal pathogens were generally detected at lower levels in the peri-implantitis group than in the periodontitis group.ConclusionWe found lower bacterial counts in the peri-implantitis group relative to the periodontitis group. Our results suggest that the peri-implant tissue is less resistant to bacteria, so even a small number of bacteria can be a risk factor for peri-implantitis and the causative agent of peri-implantitis can be bacteria other than periodontal pathogen.

A Case of Fibrolipoma of the Hard Palate

An extremely rare case of fibrolipoma in the hard palate is presented and discussed with reference to the literature. An 85-year-old woman visited the Tokyo Dental College Chiba hospital in September 2016 with the chief complaint of a mass in the hard palate. The patient had first become aware of this mass several years earlier. An examination at another hospital in June 2009 resulted in a clinical diagnosis of lipoma. Regular examinations followed every 6 months until September 2014, at which time she stopped attending these appointments because there was no change. In August 2016, however, the patient realized that the tumor was increasing in size. Although there was no pain, awareness of a foreign body in the oral cavity when eating or talking was increasing, so she decided to visit our clinic for detailed examination and treatment. At this point, the mass extended from the center to the left side of the hard palate. It measured 15 mm along the major axis, and had a clear border; nearly spherical, its surface was smooth and glossy, and was of a slightly yellowish color. The mass was painless, elastic, and soft. Computed tomography and magnetic resonance imaging revealed a tumorous lesion. Based on a clinical diagnosis of lipoma, it was subsequently excised under general anesthesia in January 2017. The tumor lay under the palatal mucosa, extending from the center to the left side of the hard palate. It was surrounded by a single-layered membranous structure, and had not adhered to the surrounding tissues. Healthy palatal mucosa and periosteum were also removed en bloc with the tumor within a safety margin of approximately 5 mm. No pressure absorption of palatine bone was seen. Histopathologically, proliferation of mature adipose tissue was observed. This was surrounded by a thin, single-layer membrane within the subepithelial connective tissue, which was covered by stratified squamous epithelium. Proliferation of fibrotic connective tissue was seen between the adipocytes. The final diagnosis was fibrolipoma. To date, at 18 months postoperatively, no recurrence has been observed and progress has been satisfactory.

Mandibular Reconstruction with Free Vascularized Fibular Graft.

An iliac block graft is the most commonly used biomaterial for reconstruction following resection of the mandible. Its use has some disadvantages, however, including limitations on the amount of bone that may be harvested, and the subsequent increase in burden on the iliac bone. Therefore, recently, free vascularized fibular grafts have been used as an alternative in some cases. Here, we report the advantages of, and issues related to reconstruction using free vascularized fibular grafts observed at Tokyo Dental College Chiba Hospital. Eight patients undergoing mandibular reconstruction using free vascularized fibular grafts between January 2003 and January 2017 were investigated. Of these, 6 were men, and 2 were women. Age ranged from 38 to 74 years (average, 54 years). Primary diseases comprised malignant tumor in 3 patients, benign tumor in 3, and radiation osteomyelitis of the mandible in 2. The defects were classified as follows according to the CAT system (Condylar Head, Mandibular Angle, Mental Tubercle): 3 cases of Body, 2 of AT, and 1 case each of TT, ATTA, and CATT. The resection range of the mandible was 5-16 cm (average, 10 cm). The single barrel technique was used in 7 cases, and the double barrel technique in 1. In terms of the flap survival ratio, complete engraftment was achieved in 6 out of the 8 cases. Two cases of radiation osteomyelitis of the mandible, with necrosis caused by vascular breakdown after wound infection, were observed, however. While the advantages of mandibular reconstruction by this method include comparatively safe conditions and functional recovery, there were also some problems. It was inappropriate for cases of radiation osteomyelitis of the mandible; those where anti-inflammatory therapy was ineffective; and those where greater resection of the soft tissue was required. Further study is needed to clarify the criteria for selecting this procedure.

Postoperative Conversion Disorder in Elderly Oral Cancer Patient.

Conversion disorder is a condition in which psychological stress in response to difficult situations manifests as physical symptoms. Here, we report a case of postoperative coma due to conversion disorder in an elderly oral cancer patient. An 82-year-old woman was referred to Tokyo Dental College Chiba Hospital with a mass lesion on the tongue. A biopsy revealed a well-differentiated squamous cell carcinoma. Surgical treatment was performed for the tongue carcinoma and tracheotomy for management of the airway. On postoperative day 5, the patient exhibited loss of consciousness (Glasgow Coma Scale: E1, VT, M1; Japan Coma Scale: III-300). The patient's vital signs were all normal, as were the results of a full blood count, brain-CT, MRI, and MRA. Only the arm dropping test was positive. Therefore, the cause of the coma was diagnosed as conversion disorder. Seven hours later, the patient showed a complete recovery.

Connective Tissue Graft for Gingival Recession in Mandibular Incisor Area: A Case Report.

We report a case of gingival recession in the mandibular incisor region requiring a connective tissue graft. The patient was a 17-year-old girl who visited the Tokyo Dental College Chiba Hospital in 2014 with the chief complaint of gingival recession in the lower incisor region. She had received orthodontic treatment for 5 years and noticed the gingival recession on completion of active orthodontic treatment in 2013. Gingival recession in tooth #31 extended 3 mm beyond the muco-gingival junction (MGJ) and was clinically diagnosed as Miller Class II recession; probing depth was 6 mm. Following initial periodontal therapy, a connective tissue graft procedure was implemented. The connective tissue was harvested from the left palate. Healing was uneventful, and the grafted site showed a favorable outcome at 6 months postoperatively. We are continuing to carefully monitor the condition of periodontal tissue.

Analysis of Needlestick and Similar Injuries over 10 Years from April 2004 at Tokyo Dental College Chiba Hospital.

Here we investigated needlestick and similar injuries reported over a 10-year period between April 2004 and March 2014. The purpose of this study was to prevent recurrence and reduce the incidence of such injuries at Tokyo Dental College Chiba Hospital. The Division of Medical Risk Management at Chiba Hospital anonymized the data to protect personal information prior to analysis. A total of 213 injuries occurred over the 10-year period investigated, but the number of cases decreased yearly. Many cases involved dental undergraduate students and dentists, followed by trainee dentists, students at the school of dental hygiene, nurses, dental hygienists, and cleaners. Suture needles, followed by injection needles, were the top two most common injury-causing instruments, contributing to approximately 50% of the total number of such cases. Many injection needle injuries occurred during tidying up, while those caused by suture needles occurred during dental treatment. Taken together, these findings suggest the importance of strict adherence to guidelines provided in safety manuals on error-free procedures and handling of instruments. Improvement in the ability to sense potential risk is essential if such injuries are to be avoided.

A study on the intrapapillary capillary loop detected by narrow band imaging system in early oral squamous cell carcinoma

ObjectiveThe purpose of this study is to determine the effectiveness of narrow band imaging (NBI) by analyzing three-dimensional (3D) images of intrapapillary capillary loop (IPCL) and recording changes over time. MethodsThis study was conducted between April 2007 and October 2011 at the Department of Oral and Maxillofacial Surgery of Tokyo Dental College Chiba Hospital. A total of 119 cases and 40 healthy volunteers were observed with NBI. Within a total of 119 cases oral squamous cell carcinoma (OSCC) was diagnosed in 48 cases (40%), leukoplakia in 26 cases (22%), oral lichen planus in 18 cases (15%), gingivitis in 5 cases (4%), aphtha in 4 cases (3.5%), ulcer in 4 cases (3.5%), erythroplakia in 3 cases (2.5%), pigmentation in 3 cases (2.5%), and other diseases in 8 cases (7%). The 40 healthy volunteers were medically examined at the regions of the gingiva, lower lip, buccal mucosa, oral floor, lateral border of the tongue, and dorsal surface of the tongue. ResultsMorphological changes of IPCL were analyzed through the construction of 3D images. The dimension, volume and density of vascular vessel were compared between OSCC, dysplasia and normal mucosa. Abnormal vascular vessels were apparent in cases of dysplasia and OSCC when examined through magnifying endoscopy with NBI. Morphological changes of IPCL such as dilation, aggregation and thickness increasing observed by NBI were certified through 3D imaging. ConclusionsThese results suggest that NBI is an effective method for the early detection of OSCC.

Correlations between Perceived Oral Malodor Levels and Self-Reported Oral Complaints.

Objectives. Even though objective data indicating the absence of oral malodor are presented to patients, they may be skeptical about the results, possibly due to the presence of some discomfort in the oral cavity. The objective of this study was to investigate whether there is an association among self-perceptions of oral malodor, oral complaints, and the actual oral malodor test result. Materials and Methods. Questions concerning self-perceptions of oral malodor and subjective intraoral symptoms were extracted from a questionnaire on oral malodor completed by 363 subjects who visited the clinic for oral malodor of Tokyo Dental College Chiba Hospital and gave consent to this study. In addition, the association of self-perception of oral malodor with values obtained after organoleptic and OralChroma measurement was analyzed. Results. No correlation between 195 subjects (54%) who were judged “with oral malodor” (organoleptic score of ≥1) and 294 subjects (81.6%) who had a self-perceptions of oral malodor was observed. Self-perception of oral malodor was significantly correlated with tongue coating (p = 0.002) and a strange intraoral taste (p = 0.016). Conclusions. Subjects with a self-perception of oral malodor were not necessarily consistent with those actually having an oral malodor. In addition, it was suggested that patients became aware of oral malodor when they felt oral complaints.

Accidental Ingestion or Aspiration of Foreign Objects at Tokyo Dental College Chiba Hospital over Last 4 Years

The aim of this study was to investigate cases of accidental ingestion or aspiration occurring at Tokyo Dental College Chiba Hospital over the last 4 years in order to determine how the incidence of such events could be reduced. Forty cases of accidents occurring at our hospital over a 4-year period commencing in 2008 (representing 27% of the total number of accidents) included accidental ingestion in 39 patients and aspiration in one. Most of these accidents occurred during the removal or placement of restorations or prosthetics, and the ingested objects were mostly crowns and inlays. Accidental ingestion or aspiration occurred more frequently in the right molar region and when procedures were conducted by practitioners with less than 1 to 7 years of experience, and especially 1 to 3 years only. A higher rate of such accidents was observed in male patients in their 50s to 70s. The conventional safety procedures developed by the Medical Risk Management Team should be adhered to wherever possible. Furthermore, we propose the following measures based on the present results: accident prevention training for students and clinical trainees; improvement of the in-hospital manual; personal coaching for those breaching the guidelines of the safety manual; and raising awareness of the need for greater care in preventing incidents of accidental ingestion or aspiration at the Tokyo Dental College Chiba Hospital.

Survey on choice of intravenous sedative agent at department of dental anesthesiology, Tokyo Dental College Chiba Hospital between 2010 and 2011.

Use of intravenous sedation is increasing in the management of dental patients in consideration of accompanying diseases and patient demand for comfort and safety. We surveyed choice of sedative agent and dosage on the basis of accompanying diseases or conditions in patients receiving treatment at the Department of Dental Anesthesiology, Tokyo Dental College Chiba Hospital between 2010 and 2011. A total of 5,256 patients were reviewed and divided into the following categories: 1) medically compromised patients (MC); 2) minor oral surgery (OS); 3) cerebral palsy (CP); 4) mental retardation (MR); 5) mental disorder (MD); and 6) dental phobia with/without gag reflex. The investigated variables were sex, age, weight, duration of sedation, and dosage of agent. Dosage of midazolam (M), M plus propofol (MP), and P alone was investigated. A total of 2,336 patients were managed by intravenous sedation during the study period. The combination of MP was used in approximately 63-79% of patients in all categories, except MC. Midazolam was used in approximately 47% in the MC group. Propofol was used in approximately 32% of patients in the MR group. Other agents (minor tranquilizers, analgesics, and so on) were used in approximately 12% in the OS group. The dose of M was approximately 0.05-0.06 mg/kg. When MP was administered, the dose of M showed no difference among groups. The dose of P, however, tended to be lower in the MC and CP groups than in the other groups. These results suggest that MP is chosen for intravenous sedation in most types of dental treatment.

Clinical evaluation of salivary periodontal pathogen levels by real‐time polymerase chain reaction in patients before dental implant treatment

ObjectivePeriodontal pathogens in dental plaque are the main causative agents of periodontitis and peri-implantitis. Detection of the presence of such periodontal pathogens early would serve as a useful tool in the diagnosis and treatment of this disease. Therefore, the purpose of this study was to investigate whether the periodontal pathogen levels in saliva were correlated with the periodontal status of patients receiving implant treatment.Materials and MethodsA total of 291 patients visiting Tokyo Dental College Chiba Hospital were divided into four groups: a no-periodontitis (np) group, a mild-periodontitis (mip) group, a moderate-periodontitis (mop) group, and a severe-periodontitis (sp) group. The levels of the following five periodontal pathogens in saliva were evaluated using real-time polymerase chain reaction: Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, Tannerella forsythia, Treponema denticola, and Prevotella intermedia.ResultsThe levels of P. gingivalis and T. forsythia were significantly higher in mop group than in np group (P < 0.05). The levels of all periodontal pathogens tested except A. actinomycetemcomitans were significantly higher in sp group than in np group (P < 0.05).ConclusionThe detection levels of the periodontal pathogens targeted in saliva samples were correlated with the periodontal status. This suggests that using saliva to screen for periodontopathic bacteria offers an easier-to-use clinical tool than the paper point method in the diagnosis and treatment of periodontitis and peri-implantitis.

The combined effects of midazolam and propofol sedation on muscle power

We performed a randomised, crossover study to investigate the effects of intravenous sedation on grip strength and bite force. Twenty male volunteers received a bolus intravenous injection of midazolam (0.02 mg.kg(-1)) together with a 30-min propofol infusion designed to achieve an effect-site concentration of 1.0 μg.ml(-1). Observed variables included bispectral index, observer's assessment of alertness/sedation, correct answer rate of Stroop colour-word test, grip strength and bite force. Grip strength decreased from a median (IQR [range]) of 483 (443-517 [380-586]) N to 358 (280-405 [108-580]) N (p < 0.001) during sedation and recovered following flumazenil administration, while bite force increased from 818 (593-1026 [405-1406]) N to 1377 (1243-1585 [836-2357]) N (p < 0.001) during sedation. Although bite force gradually returned to baseline following flumazenil administration, it remained increased throughout the experimental period. We conclude that bite force increased during intravenous sedation and that this may have clinical implications.

Analysis of Dental Treatment Performed by Dental Residents at General Dentistry Department of Tokyo Dental College Chiba Hospital Over 6 Years Following Introduction of Mandatory Dental Clinical Training System

Six years have passed since the introduction of legislation mandating at least 1 year of clinical training for those who have passed the national dentist examination. To determine whether clinical training has been appropriately implemented at the General Dentistry Department of Tokyo Dental College Chiba Hospital, a managed-type clinical training facility, the number of patients treated and types of dental and dental technical work performed by dental residents trained by the department were summarized and analyzed. The number of patients treated per dental resident increased from 11 in 2006 to 15 in 2011. By treatment type, periodontic treatment was the most frequently performed throughout the study period, followed by endodontic treatment. Conservation treatment, prosthodontic treatment with crowns/bridges, and prosthodontic treatment with dentures were performed at a similar moderate frequency, while oral surgical treatment was performed least frequently throughout the study period. The frequency of periodontic treatment increased slightly, whereas that of endodontic treatment decreased slightly or remained almost unchanged after introduction of the mandatory clinical training system. When the distribution of dental treatment performed at our department was compared with that of dental treatment performed by general dentists across Japan in 2011, our department showed a slightly lower frequency of periodontic treatment and higher frequency of endodontic treatment than the national total, whereas the frequency of other types of treatment was similar between the two populations. These results demonstrated that appropriate clinical training has been provided by our department to meet the purpose of offering dentists the opportunity to acquire the basic diagnostic and treatment abilities that would enable them to provide appropriate treatment for injuries and diseases frequently encountered in daily practice. The study also revealed some problems, such as a decreasing number of residents engaging in dental technical work each year. For additional improvement in the quality of dental clinical training, more analyses are needed to further identify and address potential problems in the system.

Effect of Swallowing Exercises in Independent Elderly

The aim of this study was to investigate the effects of swallowing exercises on oral function in independent elderly patients visiting the Department of Prosthodontics at Tokyo Dental College Chiba Hospital. Twenty-nine patients aged over 65 years (15 men and 14 women; mean age, 75.0 years) in whom treatment was completed at this college were enrolled in the study. The patients were instructed on how to perform swallowing exercises monthly (including at baseline) for the first 2 months from the start of the study and asked to perform those exercises at least once daily. At the beginning and end of the study (a 3-month study period), the Repetitive Saliva Swallowing Test was conducted and occlusal force, oral diadochokinesis, unstimulated whole saliva flow rate, stimulated whole saliva flow rate, salivary pH at rest, and salivary buffering capacity measured to determine the effects of the exercises on oral function. Analyses demonstrated significant increases in diadochokinesis rate (/ta/ and /ka/) and unstimulated whole saliva flow rate (p<0.05), suggesting that the swallowing exercises promote the maintenance and improvement of oral function in the independent elderly.

東京歯科大学千葉病院口臭外来受診患者の最近 3 年間の臨床統計

本研究では，口臭外来を受診した患者の実態，口臭質問票の回答および客観的評価である臭気測定器（オーラルクロマTM）による口臭診断との関連性を分析し，心理的口臭症患者の不安障害の傾向を捉えることができるか検討することを目的とした。対象者は，2009 年 1 月から 2011 年 12 月までに東京歯科大学千葉病院口臭外来を受診した患者 363 名とした。口臭質問票の項目の一部（性別，年齢，口臭の自覚の有無，口臭を意識した時期，口臭を意識するようになった契機，口臭による社会生活や家庭生活への影響，口臭について相談できる人の有無）とオーラルクロマTMによる検査結果の関連性を分析した。臭気測定器による分析は，臭気物質の中で口臭の強弱と強い相関が認められるCH3SH 濃度を指標とし，対象者を臭気レベルを下げるための治療が必要か否かにより，口臭なし群と口臭あり群に分けた。その結果，対象者のうち口臭を自覚する者は 8 割を超えていたが，そのうち約半数は口臭なしと診断され，口臭の自覚と口臭の有無との明確な関連性は認められなかった。口臭の診断，治療には心理的側面も含めた様々な面からのアプローチが必要であると思われた。特に心理的口臭症患者への対応では，エゴグラム等の分析を待たずに，口臭質問票の一部の項目と口臭測定結果から，不安障害を有する患者の傾向をある程度捉えることが可能であると考えられた。 日本歯周病学会会誌（日歯周誌）55(1)：15-23, 2013

Periodontal Conditions in Patients Requesting Dental Implant Treatment

Periodontal disease is considered a risk factor in dental implant treatment. The purpose of this study was to investigate the periodontal conditions in patients requesting dental implant therapy. A total of 169 patients visiting Department of Oral and Maxillo-Facial Implantology at Tokyo Dental College Chiba Hospital were targeted. The following intraoral parameters were measured in each patient: Community Periodontal Index (CPI) score, probing pocket depth (PPD), clinical attachment level (CAL) and bleeding on probing (BOP). Prevalence of patients with periodontal pockets was high: 38% and 28% of patients had a CPI score of code 3 and 4, respectively. Prevalence of teeth with one or more sites with PPD≥4mm was 27%. Moreover, clinical signs suggestive of periodontitis (PPD, CAL≥4mm) were found in 10-15% of tooth sites. Prevalence rates at sites with severe periodontal breakdown (PPD, CAL≥7mm) were 2-5%. These results further emphasize the importance of thorough periodontal assessment in patients prior to dental implant treatment.

Character Traits of Malodor Patients

Many patients visit oral malodor clinics because of malodors which are brought to their attention by friends and family, or because they note the behavior of people around them, they suspect a problem and develop a fear of having an oral malodor. However, only around 30% of such patients actually have levels of malodor high enough to bother other people. Many patients exhibit halitophobia symptoms, which present as self-perception of malodor, and thus have a strong obsession about their smell which results in distress. Here, we carried out a study on 300 outpatients who visited the Tokyo Dental College Chiba Hospital Odor Clinic. We used the Tokyo University Egogram (TEG) to elucidate character traits of affected outpatients and compared the occurrence of TEG types in these patients with those of normal individuals. We discovered that 10.4% of patients were A-dominant type, which was 10.6% lower than the 21.0% of normal individuals. On the other hand, 18.4% of patients were N-type (NP high, FC low), which was 9.9% higher than the 8.5% of normal individuals. Results revealed that very few of the malodor outpatients exhibited the trait that shows intelligence, calm judgment, and self-affirmation, and as a result enjoy their life. Instead, many of these patients tended to show high levels of kindness and appeared to be holding themselves back and exercising patience.

Matching System within Clinical Training Facilities Group of Clinical Dental Training in Tokyo Dental College Chiba Hospital

Since clinical dental training became mandatory in April 2006, Tokyo Dental College Chiba Hospital has been offering the following two types of training system: 1. a single system, and 2. a clinical training facilities group system. The clinical training facilities group system consists of program B, in which residents are trained in a cooperation-type clinical training facility for 3-4 months, and program C, in which residents are trained in two cooperation-type clinical training facilities for 7-8 months. A matching system within the clinical training facilities group is applied to select and decide on the cooperation-type clinical training facility for residents. In this system, the ranking of resident candidates that a cooperation-type clinical training facility would like to accept, and the ranking of training facilities that candidates choose are matched. The present study investigated the matching system within the clinical training facilities group in 2006, 2007, and 2008. The rate of matching to their third choice was more than 90% in program B and about 80% in program C in each year, suggesting a high matching rate. The percentage of cooperation-type clinical training facilities accepting dental residents dropped due to a decrease in the number of such residents. The distribution of accepted cooperation-type clinical training facilities is concentrated in Chiba Prefecture where our hospital, the management-type clinical training facility, is located, and the neighboring prefectures.

Survey of Accidental Ingestion and Aspiration at Tokyo Dental College Chiba Hospital

The occurrence of accidental ingestion/aspiration and preventive measures were investigated at Tokyo Dental College Chiba Hospital. In addition, the characteristics of accidents at our hospital were analyzed by surveying the awareness of accidental ingestion/aspiration to utilize the data for prevention. Accidental ingestion accounted for about 30% of accidents that occurred at our hospital in fiscal 2008, but all ingested items were naturally excreted, and no accidental aspiration occurred. Accidental ingestion most frequently occurred when dental restorations were removed. Inlays and crowns were most frequently ingested, and dentists with 5 to less than 10 years of clinical experience tended to be involved in these accidents. According to the results of the questionnaire, removal of restorations was perceived as the treatment least likely to cause accidental ingestion/aspiration. Moreover, dentists who always took preventive measures against accidental ingestion/aspiration accounted for only 40% or less on average. To avoid accidental ingestion/aspiration, repeated courses and individual instruction for repeaters and the establishment of a surveillance system along with manuals to manage the violation should be emphasized.

Color Differences between Artificial and Natural Teeth in Removable Partial Denture Wearers

The purpose of this study was to investigate differences between natural tooth color and that selected for artificial teeth in partial dentures at our department with a view to establishing criteria for obtaining greater harmonization between colors. The participants in this study comprised partial denture wearers visiting the Department of Prosthodontics, Tokyo Dental College Chiba Hospital, in whom both artificial teeth and natural teeth were present in the maxillary anterior tooth area. Natural tooth color was measured according to VITA classical shade guide number using a dental color measurement apparatus. Artificial tooth color in partial dentures produced at our department was investigated by referring to medical records. Color of 28 participants' natural teeth and 345 participants' artificial teeth was investigated. Differences in color distribution between the natural and artificial tooth were analyzed using the Fisher exact test. The most frequent color of natural tooth was C-type, accounting for 39%, followed by D- at 32%, A-at 22% and B-type at 7%. In terms of artificial tooth color, A-type was the most common (97%). The color distribution of natural teeth differed significantly from that of artificial teeth in partial dentures. These results suggest that artificial tooth color did not harmonize with the color of the natural teeth in partial denture wearers.