How dental loan payments work: amortized vs interest-only

Why loan structure matters in dentistry

Dental school, residency, relocation, equipment, practice acquisition, and startup costs can all involve borrowing. The monthly payment is the visible part of the loan, but it is not the whole cost. A lower monthly payment can sometimes mean a longer repayment period, more interest, or a large balance waiting later.

For dental students and early-career dentists, the basic distinction is between an amortized loan and an interest-only period. The first gradually pays down the principal. The second keeps payments lower for a time but does not reduce the balance unless extra principal payments are made. This article explains the difference using general loan math. It is not borrowing, investment, tax, or legal advice.

For U.S. market context only, ADEA reported that indebted dental school graduates in the class of 2025 had average educational debt of $297,800, and its 2025 senior survey summary found that dental school loans accounted for most reported education debt among respondents with debt. That figure should not be treated as a Canadian benchmark, but it shows why repayment structure is a practical topic for dental graduates.

Key terms before you compare loans

Before comparing monthly payments, define the terms. Canada’s Financial Consumer Agency explains that personal loan cost depends on the amount borrowed, interest, fees, and term, and that a longer repayment term can make the total cost higher even when the monthly payment is lower. Federally regulated lenders in Canada must also disclose information such as principal, payment amount and frequency, term, amortization period, annual interest rate, APR, and other charges.

• Principal: the amount borrowed.
• Interest: the cost charged for borrowing the money.
• APR: the annual cost of borrowing expressed as a percentage when it differs from the stated interest rate.
• Term: the period covered by the loan agreement or rate arrangement.
• Amortization period: the time it takes to repay the loan in full if payments are made as scheduled.
• Fees: setup, administrative, appraisal, broker, prepayment, or other charges that can change total cost.

How an amortized loan works

An amortized loan is designed so each scheduled payment covers interest and some principal. Early in the schedule, a larger share of the payment goes to interest because the balance is still high. Later, as the balance falls, more of each payment goes to principal. The CFPB describes this shift in amortizing loans and notes that longer loan terms usually lower monthly payments but increase lifetime interest.

Example: a $100,000 loan at 8% annual interest amortized over 10 years has a monthly principal-and-interest payment of about $1,213. Over 120 payments, the total paid would be about $145,593, including about $45,593 in interest. This simplified example excludes fees, insurance, variable-rate changes, prepayment penalties, and lender-specific rules.

How an interest-only period works

An interest-only payment covers the interest for a period but does not reduce the principal. The CFPB explains that an interest-only loan requires scheduled payments of interest for a specified time, and that the amount owed does not go down during that period unless the borrower pays extra principal.

Example: on the same $100,000 loan at 8% annual interest, an interest-only payment would be about $667 per month. That feels much lighter than $1,213. But after 36 interest-only payments, the borrower would still owe the original $100,000 principal. If the remaining balance then had to be amortized over seven years at the same 8% rate, the monthly payment would rise to about $1,559. The lower early payment did not erase the debt. It delayed principal repayment.

Amortized vs interest-only: a worked example

The table below compares the two structures on the same simplified $100,000 loan at 8% annual interest. The interest-only column assumes 36 interest-only payments, after which the full principal is amortized over seven years.

Measure	Amortized (10 years)	Interest-only (36 months), then amortized
Early monthly payment	~$1,213	~$667
Principal after 36 payments	Reduced on schedule	Still $100,000
Payment after interest-only period	~$1,213 (unchanged)	~$1,559 (amortized over 7 years)
Total paid over 10 years	~$145,593	Higher once delayed interest is added
Total interest over 10 years	~$45,593	Higher once delayed interest is added

The lower early payment in the interest-only column does not erase the debt. It delays principal repayment, which is why the later payment is higher and the principal is unchanged after 36 payments.

When the lower payment is not the cheaper loan

A lower payment can be useful when cash flow is tight, but it should not be confused with a lower cost. A longer term, interest-only period, higher interest rate, or added fees can increase total cost. FCAC’s personal loan guidance gives a simple principle: understand total cost before deciding, including payment amount multiplied by number of payments, interest, fees, and term.

For a dental context, this matters when comparing a line of credit, student-loan repayment option, equipment financing quote, practice acquisition loan, or temporary interest-only bridge. The decision should model at least three numbers: monthly cash flow, total interest, and remaining balance after the first few years.

Questions to ask before relying on a loan quote

A loan quote should give enough detail to reproduce the payment. If it cannot be reproduced, ask for the missing information.

• What is the principal amount being borrowed?
• Is the rate fixed or variable? If variable, what index or benchmark does it follow?
• What is the APR or total cost of borrowing after fees?
• What is the term, and what is the amortization period?
• Are payments principal-and-interest, interest-only, or another structure?
• If there is an interest-only period, when does principal repayment begin and what will the payment become?
• Are extra payments allowed, and are there prepayment penalties?
• What balance will remain after one, three, five, and ten years?

How to use the paired DentiPath tool

Use the DentiPath Loan Repayment Calculator to compare amortized and interest-only structures side by side. Look beyond the first monthly payment. Model the total interest, final payment, cash out, and remaining balance. Then stress test the result by changing the interest rate, payment period, or extra-payment amount.

Key takeaway

Compare both structures with the Loan Repayment Calculator before relying on any quote.

Sources

• Financial Consumer Agency of Canada, Personal loans.
• Consumer Financial Protection Bureau, What is amortization and how could it affect my auto loan?
• Consumer Financial Protection Bureau, What is an interest-only loan?
• Financial Consumer Agency of Canada, Personal loans: know your rights.
• American Dental Education Association, Educational Debt.
• American Dental Education Association, Dentists of Tomorrow 2025.